EMS MEd Blog

Challenging the Dogma of “All Clear”: Is Hands-On Defibrillation the Next Step in Reducing the Peri-shock Pause?

by Brandon Bleess, MD EMT-T and Jeremy Cushman, MD, MS, EMT-P, FACEP, FAEMS

Case:

A 54-year-old male is working in his yard when he collapses to the ground and his wife calls 911. The call is dispatched as a cardiac arrest and the patient's wife is instructed to perform CPR per pre-arrival instructions. Upon EMS arrival, the patient is found to be apneic and pulseless. EMS relieves the patient’s wife and compressions are continued while the patient is connected to the monitor. The monitor is charged prior to the next pulse check where the patient is noted to be in ventricular fibrillation. Everyone takes the time to drop contact with the patient as the operator declares “everyone clear” before shocking and resuming compressions and ventilation.

When debriefing the case, one of the paramedics brings up the idea of hands-on defibrillation that he attended a lecture on at a recent conference. Is it safe to defibrillate a patient while CPR is actively being performed?

The Evidence For:

There is little question that high quality, continuous compressions improve neurologic outcomes in patients with out-of-hospital cardiac arrest. The choice of outcome here is important: compressions are really to maintain some oxygenated blood flow to the brain in order to keep it alive long enough to get the heart started again. All too often, ROSC is achieved but the patient has anoxic brain injury which can be a result of extended down time or ineffective compressions.

Thus the goal in performing compressions is to minimize interruptions, for every time compressions are stopped it takes a significantly longer time to return to the flow state that existed just prior to stopping them [1-5]. With the goal of increasing compression fraction and thus improving neurologic outcomes, the American Heart Association (AHA) began recommending charging the defibrillator during chest compressions in 2005 [6]. Multiple studies have since demonstrated that charging during compressions decreases both post- and peri-shock pauses [7-9]. These included the Resuscitation Outcomes Consortium (ROC) PRIMED trial which found that the median peri-shock pause was reduced from 21 seconds to 9 seconds with compressions during charging. This reduction in peri-shock pause lead to a significant increase in mean chest compression fraction (0.77 vs 0.70, 95% CI: 0.03-0.11), an independent factor in increasing survival [9, 10, 11]. Thus, the traditional analyze – charge - shock pattern should be changed to charge – analyze- shock.

But can we go one step further and continue CPR during defibrillation? After decades of “I’m clear, you’re clear, we’re all clear,” it might be time to let that go the way of the backboard in the closet of EMS dogma. Traditionally, external defibrillation has been considered a safety hazard to rescuers and clearing the patient is an almost universal practice, but there is little data to support this notion in the age of adherent defibrillation pads [12]. Indeed, there is now evidence to suggest that hands-on defibrillation is actually safe.

How much energy is potentially transferred to the compressor during hands-on defibrillation? Defibrillators generally deliver 30-40 A of current with each shock, and the threshold for perception is 2.5-4.0 mA, and exposure becomes painful at 6-10 mA. In healthy adults 200-500 mA of current is thought to be needed to induce ventricular fibrillation with incidence correlating linearly to increasing current [12].

Lloyd et. al. found that the amount of "leakage" (the amount of current going to the provider) in an ideal setting (outpatient cardiac electrophysiology evaluations) was well below the allowable minimum [13]. Keep in mind, this study was looking at microamps of current. The allowable being 3,500 microamps and the leakage was an order of magnitude less than that. To put this into further perspective, when pacing patients with transcutaneous pacing generally 60-80 mA is required for capture. Compared to the study’s mean leakage of 283 µA or 0.28 mA, transcutaneous pacing uses over 200 times the amperage to create capture.

Neumann et al. in 2012 followed up this study by inducing ventricular fibrillation in a swine model and comparing hands-on versus hands-off defibrillation. They found that in the hands-on group, chest compressions were interrupted for 0.8% versus 8.2% of the total CPR time (P=0.0003) and coronary perfusion pressure was restored earlier to its pre-interruption level (P=0.0205). They also found that not only was the defibrillation shock imperceptible, but the compressor wearing a cardiac monitor had no arrhythmias noted [14].

Insulating the provider from current leakage is probably one of the easiest ways to protect the compressor from harm. This was studied by Deakin et al. in 2015 using Class 1 electrical insulating gloves while simulating hands-on defibrillation. They found that the median current leakage was 20 μA from the 61 shocks studied, and even at 360 J the median current leakage was 27 μA. The highest recorded leakage was 28 μA, all below the 1 mA threshold they set [15]. More recently in 2016, Wampler et al. published a study looking at perception of shocks using multiple insulating barriers, including nitrile gloves, firefighting gloves, a neoprene pad, and a manual compression/decompression device. Out of the 100 shocks with no barrier device, all but 1 shock was not detected. Out of 500 shocks, only 5 were detected by the compressor - none causing harm, and most importantly the CPR puck prevented any detection [16].

The Evidence Against:

Closer evaluation of these studies may give some rescuers pause. In the 2008 Lloyd study, 8 of the 72 phases (36 shocks, 11.1%) exceeded the 500 µA threshold [13]. In the Neumann study of 2012, the compressors wore 2 pairs of polyethylene gloves which is outside the standard practice of many providers [14]. While Deakin’s study presents some very convincing data in relation to the safety, the compressor was wearing Class 1 electrical insulating gloves. According to the Occupational Safety and Health Administration (OSHA) regulation 29 CFR 1910.137, Class 1 gloves are rated for a maximum usage of 7500 V AC and are proof tested to 10,000 VAC and 40,000 VDC [18]. Defibrillators typically fall well below this at around 2700 V for a biphasic defibrillator.

In 2014, Lemkin et. al. published a cadaver study where they measured the differential of the voltages at various points on the body with several skin preparations (bare, water, saline, ultrasound gel). This allowed them to collect the resistance and exposure voltage in relation to anatomic landmarks to create a map of the providers’ exposure. From there, they derived a formula to measure the rescuer-received dose (RRD) to represent the proportion of energy the rescuer could receive from a shock to a patient. Their results demonstrated the rescuer-exposure could exceed 1 J in any location at some energy level, and reached as high as 9.4J on the anterior chest wall [17]. The argument made is that 1 J could potentially cause a provider to be shocked into ventricular fibrillation themselves. Since this does not include any barriers, it would apply if there was a large tear in the glove or the rescuer was contacting the patient without any gloves.

Conclusion:

While the literature suggests that hands-on defibrillation is safe, it should occur at the discretion of the compressor who should consider wearing two pairs of gloves or utilize both gloves and a CPR-feedback device if performing the procedure. There are no studies that have measured the effect of this on clinical outcome, although it is postulated that increased compression fraction is a useful surrogate. At minimum, the charge-analyze-shock method should be used during every defibrillation to minimize the hands-off time and increase the compression fraction.

For additional Resources, REBEL EM published the following review of Hands-On-Defibrillation: CPR Hands-On or Hands-Off Defibrillation

EMS MEd Editor: Maia Dorsett (@maiadorsett)

References:

1. Berg RA, Sanders AB, Kern KB, et al. Adverse hemodynamic effects of interrupting chest compressions for rescue breathing during cardiopulmonary resuscitation for ventricular fibrillation cardiac arrest. Circulation. 2001 Nov 13;104(20):2465-70.

2. Cunningham LM, Mattu A, O’Connor RE, Brady WJ. Cardiopulmonary resuscitation for cardiac arrest: the importance of uninterrupted chest compressions and cardiac arrest resuscitation. Am J Emerg Med. 2012 Oct;30(8):1630-8.

3. Paradis NA, Martin GB, Rivers EP, et al. Coronary perfusion and the return of spontaneous circulation in human cardiopulmonary resuscitation. JAMA. 1990 Feb 23;263(8):1106-13

4. Hazinski MF, Nolan JP, Aicken R, et al. Part 1: executive summary: 2015 International Consensus on Cardiopulmonary Resuscitation and Emergency Cardiovascular Care Science With Treatment Recommendations. Circulation. 2015;132(16)(suppl 1).

5. Neumar RW, Shuster M, Callaway CW, et al. Part 1: executive summary: 2015 American Heart Association Guidelines Update for Cardiopulmonary Resuscitation and Emergency Cardiovascular Care. Circulation. 2015;132(18)(suppl 2).

6. 2005 American Heart Association Guidelines for Cardiopulmonary Resuscitation and Emergency Cardiovascular Care. Circulation. 2005;112:IV1–IV203.

7. Perkins GD, Davies RP, Soar J, Thickett DR. The impact of manual defibrillation technique on no-flow time during simulated cardiopulmonary resuscitation. Resuscitation. 2007;73:109–114.

8. Edelson DP, Robertson-Dick BJ, Yuen TC, et al. Safety and efficacy of defibrillator charging during ongoing chest compressions: a multi-center study. Resuscitation. 2010;81(11), 1521-1526.

9. Cheskes S, Schmicker RH, Verbeek PR, Salcido DD, Brown SP, Brooks S, Menegazzi JJ, Vaillancourt C, Powell J, May S, et al. The impact of peri-shock pause on survival from out-of-hospital shockable cardiac arrest during the Resuscitation Outcomes Consortium PRIMED trial. Resuscitation. 2014 Mar; 85(3):336-42.

10. Christenson J, Andrusiek D, Everson-Stewart S, et al. Chest compression fraction determines survival in patients with out-of-hospital ventricular fibrillation. Circulation. 120 (2009), pp. 1241-1247.

11. Cheskes S, Schmicker RH, Christenson J, et al. Peri-shock pause: an independent predictor of survival from out-of-hospital shockable cardiac arrest. Circulation. 124 (2011), pp. 58-66.

12. Brady W, Berlat JA. Hands-on defibrillation during active chest compressions: eliminating another interruption. Am J Emerg Med. 2016 Nov;34(11):2172-2176.

13. Lloyd MS, Heeke B, Walter PF, Langberg JJ. Hands-on defibrillation: an analysis of electoral current flor through rescuers in direct contact with patients during biphasic external defibrillation. Circulation. 2008 May 13;117(19):2510-4.

14. Neumann T, Gruenewald M, Lauenstein C, Drews T, Iden T, Meybohm P. Hands-on defibrillation has the potential to improve the quality of cardiopulmonary resuscitation and is safe for rescuers—a preclinical study. J Am Heart Assoc. 2012 Oct;1(5):e001313.

15. Deakin CD, Thomsen JE, Løfgren B, Petley GW. Achieving safe hands-on defibrillation using electrical safety gloves—a clinical evaluation. Resuscitation. 2015 May;90:163-7.

16. Wampler D, Kharod C, Bolleter S, Burkett A, Gabehart C, Manifold C. A randomized control hands-on defibrillation study- Barrier use evaluation. Resuscitation. 2016 Jun;103:37-40.

17. Lemkin DL, Witting MD, Allison MG, Farzad A, Bond MC, Lemkin MA. Electrical exposure risk associated with hands-on defibrillation. Resuscitation. 2014 Oct;85(10):1330-6

18. https://www.grainger.com/content/qt-electrical-safety-gloves-inspection-262

EMS: The Best Kept Secret in Healthcare

by Maia Dorsett, MD PhD

At the end of my third year of residency, I was in the process of solidifying my decision to pursue a fellowship in EMS. I was on rotation in the Medical ICU and we were having an informal conversation about plans following residency. When I stated that I planned to pursue an EMS fellowship, the ICU Attending asked what it was.

My response?

EMS is the subspecialty of medicine that encompasses provision care beyond the borders of the hospital, at the level not only of individual patients but the entire community. That the care was not limited to 911 response in the traditional sense, but also public health, community education, disaster preparedness, provision of continuity of care following hospital discharge and in fact, to every critically ill patient transferred to his very own ICU. From then on, I pulled up available EMS records on every admission to point out the critical and often life-saving interventions provided to patients before they entered the hospital borders. My mission was to highlight the scope and importance of care provided by EMS providers.

I am not sure if this ICU attending – and the countless others who stated that they have never heard of an ‘EMS fellowship’ - were unaware of what EMS stands for. I think that they did not recognize the term in the context in which it was presented; they did not recognize it as a physician subspecialty, let alone a practice of medicine. I’m sure that those who did not recognize the term ‘EMS fellowship’ would expect a prompt and competent medical response if they were to call 911 from their living room or public place. In the grand scheme of things, EMS is relatively new. Accidental Death and Disability, which spurred the development of both EMS and Emergency Medicine, was only published a half century ago. EMS was only approved as a physician subspecialty in 2010, with the first board certifying examination offered in 2013. Like many developments that are also relatively young– the internet, cellular data network - EMS has become an assumption of peoples’ lives. Much like the delayed knowledge translation window between quality research and change in practice, moving the behemoth of the house of medicine to change the way it thinks is a long, arduous and inefficient process.

When it comes to recognition of EMS as a practice of medicine, we need to speed things up. Advocacy for our specialty is advocacy for our patients.

The reason?

Failure to recognize EMS as a practice of medicine stunts the growth of the specialty towards the model set out in the EMS Agenda for the Future:

“Emergency medical services (EMS) of the future will be community-based health management that is fully integrated with the overall health care system. It will have the ability to identify and modify illness and injury risks, provide acute illness and injury care and follow-up, and contribute to treatment of chronic conditions and community health monitoring. This new entity will be developed from redistribution of existing health care resources and will be integrated with other health care providers and public health and public safety agencies. It will improve community health and result in more appropriate use of acute health care resources. EMS will remain the public’s emergency medical safety net.”

While small steps have been made, the defacto situation is that EMS is reimbursed as a taxi service, mobile integrated healthcare programs are stunted, EMS providers are disrespected and underpaid, national certification of EMS providers fails to be 100% nationally accepted, EMS research is still underperformed and underfunded, hospitals fail to share outcome data and operational metrics rule assessments of EMS quality.

There are many different approaches to changing the status quo. EMS physicians and providers with significantly more experience and knowledge than me are pursuing those routes. But as someone new to EMS (a lab nerd turned emergency physician who caught the EMS bug mid-residency), I can tell you that part of every approach needs to be explaining the specialty of EMS not only to the public and lawmakers, but to our colleagues in medicine. I have now given talks on the principles of and barriers to Mobile Integrated Healthcare in a limited number of venues – three different EM residencies and a conference on healthcare overuse. In every situation, audience members have been surprised and inspired by how EMS can be used to provide patient-centered care with decreased healthcare utilization. They have been similarly frustrated by the payment by transport model. They have shared in our vision for a truly integrated healthcare system.

For our healthcare system to meet its potential to improve the health of our communities, it must be transformed. Many of us became EMS physicians because we wanted to be part of this transformation.

Those of us who took the EMS Boards in September are anxiously awaiting exam results. Many if not most of us put ourselves through the exam not for better pay or a new position, but because of dedication to the specialty – to the knowledge that we can positively influence the lives of an incredible number of people by improving the quality of care they receive on a system-wide level. It’s time that our colleagues in medicine understood what we actually do.

A debate of supraglottic proportions... the conclusion

The Case

It’s a brisk fall afternoon when an ALS unit is dispatched to the home of a 62 yo female in respiratory distress. She lives on the third story of an apartment building. The team carries their gear upstairs to find a woman in severe distress. She is obese, tripoding and beginning to get combative. The medics are setting up their CPAP and calling for assistance when the patient stops fighting and becomes apneic. Two-person BVM is initiated but the patient is difficult to ventilate and oxygen saturations remain poor. The medic decides to attempt to intubate, but is unsuccessful after one attempt and they decide to move on to a supraglottic airway.

Which supraglottic airway should they be using?

What supraglottic airway is available within your EMS system? Why is it preferred and what are its advantages over the alternatives?

Our readers shared their comments - and there were a lot of them. A number of important perspectives were voiced by our readership regarding their preferred supraglottic airway.

Supraglottic Airways: A Brief Review

First developed as an operating room adjunct, supraglottic airways have now been widely adopted in prehospital care. There are a wide-variety of subtypes [1], but our readers described prehospital use of predominantly two subtypes:

Laryngeal Mask Airway (LMA): The LMA was invented in 1988 by a British Anesthesiologist, Dr. Archie Brain. It involves a mask component connected to a ventilation tube and is designed to sit in the patient’s hypopharynx and cover the supraglottic structures. Most LMAs are elliptical in shape with an inflatable cuff. The i-gelTM, a modification of the LMA device, was invented in 2003. Rather than having an inflatable cuff, the i-gelTM is made from a thermoplastic elastomer that conforms to the pharyngeal and laryngeal anatomy. (Figure 1A). Most widely used LMA models, such as the LMA-SupremeTM or the i-gelTM , have ports to allow for gastric decompression.

Laryngeal-Tube (LT): The laryngeal tube was first introduced in the US in 2003 by King Systems. The LT is designed to intubate the esophagus. The device has two cuffs, a distal esophageal cuff and a proximal oropharyngeal cuff, which inflate with a single inflation port (Figure 1B). It is available with (LTS-D) and without (LT-D) a gastric decompression port.

Figure 1: Ideal positioning of LMA-type and LT supraglottic airways.

Ease of Use

The majority of commenters used or preferred an LMA (and the i-gel TM specifically) because they felt that it was easy to use and lead to a high first pass success rate:

“Igel! Easy to use, quick...” – Phil

“We having been using igel for several years and very happy. Success first pass greater than 90% easy to switch to et no cuffs.” – Peter

“From a moderate-sized, midwestern, single county urban system: Our system (paramedics) began using the igel over a year ago and we are just now starting to work with select first response agencies to incorporate the device in their tool box. We have had better first pass success rates with the igel than the King. There are less "moving parts" and it seems to be easier to troubleshoot and replace if necessary due to size/fit issues.” - Dena Smith

“ We formerly used King LT, but switched to LMA Supreme a year or two ago system wide. Providers prefer the LMA.” – Ian Smith

“King but now looking at switching to I-gel as easy to use and have good feedback in field trials.” – Jeff Rabrich

“We have been using the LMA Supreme for about 5 years with great success”. – Gary McCalla

“WE like the IGel.
Easier to train on and use than the prior King.
Capital City Fire & Rescue, Juneau, AK” - Quigley Peterson

“We use Igel.
easy, quick. no cuff to inflate, no syringes, soft material and hard to inflict airway trauma.
We have first pass success rate for igel on cardiac arrest patients of around 93% (50% placed by BLS and 50% placed by ALS)....no difference in success rate between ALS/BLS.
this is after several hundred deployments over past 1.5 years.
vomit is issue, but it is issue with any airway including ET tubes.
moved to Tube Tamers to secure (can accommodate ET or supraglottics) (using OR models).” – Ryan Jacobsen

“Approximately one year into Igel (replacing King) with summary stats not yet available. Choice was made based upon some evidence for more rapid placement, Greater size range, Some local events of balloon failures with King (perhaps, technique related), and a theoretic concern regarding carotid blood flow in humans lead to our decision to use the Igel as our 'rescue' airway.”- Jim Nania M.D., Spokane County EMS, Washington State

“King! Easy to use. Some evidence to support ease of use and successes. https://www.ncbi.nlm.nih.gov/m/pubmed/17907036/?i=5&from=king%20airway%20guyette” - - -Jeremiah Escajeda

What do published studies say about first and second pass success rate?

A number of studies have been performed to either evaluate a supraglottic placement success in live patients. There are relatively few randomized trials, and all were in elective surgical cases. Overall, the first pass placement success rates of the devices are variable: King LTD (53-92%), LMA supremeTM (72-96%), and i-gelTM (74-97%) and the variability in operators and clinical setting make it difficult to determine if there are any clinically significant differences in device-placement success (Table 1), [2-18].

While the table above by no means represents a rigorously-derived summary such as would be included in a systematic review, one simple observation is that each device has predominantly been evaluated in the clinical setting for which it was initially developed: LMA devices (i-gelTM and LMA-SupremeTM) in the operating room and LT in out-of-hospital studies. This difference in intended setting was the topic of a subset of comments left on the discussion forum post:

“We switched to igel for a one year trial. So far results are mixed. Our medical director doesn't like the long list of manufacturers contraindications. i.e. Non-fasted patients for routine and emergency anaesthetic procedures. Patients with an ASA or Mallampati score of III and above. Trismus, limited mouth opening, pharyngo-perilaryngeal abscess, trauma or mass.If this device is a rescue airway for an unsuccessful ETI. If it was an unsuccessful intubation attempt due to difficulties or trauma, an igel is contraindicated. Not to say the king was any better or worse but it didn't have the box contraindications. Would love some more provider insight.” - Joshua

“This is a great discussion and where we need to focus on the context of the airway's application. First, the Mallampati scale holds virtually no relevance to emergency situations out of hospital. By definition, many of our patients will be Class III and above due to the presence of an acute, life threatening condition. In fact, the lack of visualization of the posterior oropharynx (Mallampati 4) might serve as an actual indication for these devices!” – Ben Lawner

“Let me start with a disclosure. I'm an anesthesiologist and paramedic. Our system in Upstate NY is a King system and I would like us to become an iGel system. The King was designed as a rescue airway tool for EMS. LMAs in general are a hospital tool that has come over and been adapted to EMS as a rescue device. I'm just guessing here, but my hospital system probably uses > 500 disposable LMAs for every one King airway that comes into our Level 1 quaternary academic medical center. The market for LMA manufacturers is dramatically bigger than the market for King airways.

If we polled physicians that manage airways in the US and asked what type of airway is available to them as a SGA for rescue purposes, what percentage would say King airways? I am currently not aware of any hospitals that purchase King Airways as rescue devices and they certainly don't buy them as primary airway devices. In fact, the only reason most anesthesiologists know about King airways is because we are occasionally called up the EM department to switch them out to an ETT.

I'm not aware of any direct evidence comparing the two. It's pretty obvious to me though that less cuffs and balloons means less chance of malfunction in a uncontrolled environment. The iGel can be switched out to an ETT in a much safer manner once oxygenation has been achieved. The iGel has nothing that breaks or tears. I could see the King being preferred in a patient who required very high peak inspiratory pressures to achieve adequate ventilation, but that's pretty nuanced for a rescue device.

Joshua, your medical director won't see those contraindications change anytime soon. EMS is likely the King airway's near total business line. EMS is a tiny portion of the iGel's manufacturers business, so they probably won't bother to make that investment. I can assure you that LMAs are used as rescue devices in CICO or CICV (cannot intubate, cannot oxygenate/ventilate) situations in hospitals around the world on a daily basis. LMAs have saved more than a few patient's lives in my practice and will continue to do so. I'll let you know when I start using the King, but don't hold your breath.” – Christopher Galton

Although not have been developed specifically for prehospital use, the LMA-devices are widely used as rescue devices in emergency and prehospital settings, including in cases of severe facial trauma [19,20]

Facilitation of intubation:

In his commentary above, Dr. Galton brings up an important point that was echoed by other commenters – the ability to intubate through the device rather than needing to remove the device to intubate.

“IGel and King used in SW Ohio. Prefer IGel...it’s easier to use and capable of exchange for ETT in Hospital without removing the device. King has to be removed for patient to be intubated. I’m intrigued, though, by the Intubating King assuming it eventually becomes available in US.” – Josh B

“We're an iGel shop. I moved us from the King several years ago and we've been pleased. I disliked the airway maceration I saw in the ED when I eventually swapped out the King for an ET. – Jeff Jarvis

With its current design, the LT must be removed in order for endotracheal intubation to occur. One concern for any airway manipulation that occurs prior to endotracheal intubation is whether a supraglottic device may cause enough perilaryngeal tissue trauma to make subsequent endotracheal intubation more difficult. In a randomized comparison of the i-gelTM, LMA SupremeTM and LTS-D devices in the operating room, the authors evaluated the incidence of “airway morbidity” caused by each of the devices [3]. They assessed how often the device had blood on the outside of it after removal and whether patients later complained of sore throat or dysphagia. In comparison with the i-gel (13%) or LMA-supreme (13%), the LTS-D more often had blood on the outside of the device (37.5%, p=0.006). This correlated with a significant increase in the incidence of subsequent sore throat or dysphagia. Whether this type of “airway morbidity” has any predictive value at all for increased difficulty in airway securement after device removal is unclear.

The ventilation port of i-gelTM airway is large enough to facilitate subsequent endotracheal intubation through the device [21]. This ideally should be performed using fiber-optic guidance as blind endotracheal intubation through an i-gel has a low success rate at least in a manikin study [22]. Exchange of a King-LT over a gum-elastic bougie should not be pursued; in one cadaver, this led to penetration of the right aryepiglottic fold by the bougie which subsequently ended up in the soft tissues of the neck [23]. Intubation around the King airway using video laryngoscopy and a gum-elastic bougie has been described [24].

Safeguards are key.

One group of commenters made the important point that no matter which supraglottic was used, correct placement and adequate oxygenation and ventilation must be ensured:

“Either as long as you use waveform capnography to confirm placement! No airway is foolproof....must be confirmed!” – Veer Vithalani

“Veer is spot on about requiring EtCO2 just like we do for intubation (great paper!).” – Jeff Jarvis

“I have both King and iGel at my agencies. Both are widely used and accepted by my crews.
We have slowly moved toward the iGel for a few reasons:
1. No balloon to inflate
2. No added pressure (from a balloon) in the hypopharynx which doesn't impede carotid flow (pig and cadaver studies)
3. Gastric port (12 Fr) can be inserted into the stomach (except for size 1)

Downsides of the iGel:
1. No gastric port for the size 1
2. Packaging for the iGel consumes a lot of space compared to king
3. Cannot use commercial tube holders to stabilize the pediatric sizes.
a. Smaller sizes do not have the strap - adult sizes do.
b. Without the strap the iGel may "pop" out ever so slightly and the provider may not realize it
4. Intersurgical requires that the agency sign a waiver since the product was not intended for field airway use

My overall feeling is that iGel is preferred, yet I like the King and agree with what Veer said in his comment.”- Peter Antevy

“Agree with the comments about the absolute need for capnometry. Our first responders are using a colormetric device and our paramedics use waveform capnometry. We do have prolonged resuscitation times (we generally do not transport unless we have ROSC and have stabilized the patient). As with any device there are considerations, however training and feedback to providers seem to increase the success of its use.” – Dena Smith

As voiced in the commentary by Dr. Vithalani, as with endotracheal intubation, supraglottic airways should always be confirmed with continuous in-line capnography to confirm both initial placement as well as safeguard against unrecognized dislodgment of the device. Supraglottic airways should be secured, as they will dislodge with similar force to an endotracheal tube [24]. Vithalani et. al. studied the incidence of unrecognized failed airway management using a supraglottic airway device (King LTS-D) within their EMS system [25]. They retrospectively reviewed continuous capnography tracings of 344 the supraglottic airway attempts. Objective successful airway placement was defined as a sustained 4-phase end-tidal waveform greater than or equal to 5 mmHg for the duration of patient care, while subjective successful placement was defined as documentation of successful placement by the EMS provider. They found that only 85.1% of subjectively successful SGA placements met objective criteria for successful placement. Conversely, 4 of 28 (14%) of SGA airways that were removed because they were deemed failed by the providers actually met the objective criteria for success. The main conclusion of this paper is an important one:

“This study points to the critical necessity for objective measurement of airway management utilizing a supraglottic airway device… adequate education, training and quality assurance processes must be in place to ensure appropriate use and interpretation of continuous waveform capnography by EMS providers.”

Agreement on type of device, adequate system-wide training on its use and subsequent quality review to ensure that it is used with proper indications and quality controls remain both barriers and requirements for effective implementation or system-wide change:

“We've used intubating LMAs (disposable), Kings and now Air Qs. All work fairly well. In my opinion the most important thing is train intensively, QA thoroughly and make sure your paramedics have a healthy respect for the difficult airway.” - Marc Restuccia

“Currently using King LT, which we switched to from Combi-tube a number of years ago. Contemplating a switch to iGel, based on reported simplicity of use and reported good results. One challenge is getting 2 EMS medical directors and 13 EMS agencies to come to agreement for a system-wide change.” – Paul Rostykus

Patient-centered outcomes

“In terms of evidence base, there's really not a lot when it comes to the best "backup airway" decision based upon patient centered outcomes. The supraglottic airways can certainly temporize a difficult situation, but I struggle with evidence based recommendations. The King Airway seems quite popular, but I've encountered more than a few problems with dislodgement and ineffective ventilation. In terms of tried and true airways, the "LMA advantages" include: ease of insertion, quick deployment, and relative lack of side effects. LMAs have been used successfully for quite some time and are arguably the most well studies. Granted, we adapt airways for prehospital use, and there really is no "one size fits all" when it comes to the airway management of sick patients in the out of hospital setting.” – Ben Lawner

As voiced by Dr. Lawner, the supraglottic debate is similar to many clinical situations in prehospital care where there are few evidence-based recommendations to support clinical decision making based on patient-centered outcomes. Many aspects discussed with respect to supraglottic airways – such as of ease of use and successful placement or effect on carotid blood flow – may be useful surrogates for patient-centered outcomes but fall very short of where we as a specialty need them to be. Ease of use is basically an operational outcome, but quality in medicine is really about patient outcome and from this perspective, the debate of supraglottic proportions continues.

Take Home

The most commonly used devices amongst our readers are the i-gelTM, King LT, and LMA-SupremeTM. Current data regarding overall ease of use find overall high success rate within two attempts for all devices. Regardless of which device is used, there must be rigorous training not only on placement, but continuous end-tidal capnography as a means to ensure initial placement and prevent unrecognized device dislodgment.

Summary of discussion comments by EMS MEd Editor, Maia Dorsett MD, PhD (@maiadorsett)

For an excellent review and more in-depth discussion of supraglottic airways, we highly recommend Darren Braude’s talk available through the EMS Medicine Live site: http://www.ems-medicine.com/single-post/2016/05/31/Extraglottic-Airways-Updates-Controversies

References

1. Ostermayer, D. G., & Gausche-Hill, M. (2014). Supraglottic airways: the history and current state of prehospital airway adjuncts. Prehospital Emergency Care, 18(1), 106-115.

2. Gatward, J. J., Cook, T. M., Seller, C., Handel, J., Simpson, T., Vanek, V., & Kelly, F. (2008). Evaluation of the size 4 i‐gel™ airway in one hundred non‐paralysed patients. Anaesthesia, 63(10), 1124-1130.

3. Russo, S. G., Cremer, S., Galli, T., Eich, C., Bräuer, A., Crozier, T. A., ... & Strack, M. (2012). Randomized comparison of the i-gel™, the LMA Supreme™, and the Laryngeal Tube Suction-D using clinical and fibreoptic assessments in elective patients. BMC anesthesiology, 12(1), 18.

4. Fenner, L. B., Handel, J., Srivastava, R., Nolan, J., & Seller, C. (2014). A Randomised Comparison of the Supreme Laryngeal Mask Airway with the i-gel During Anaesthesia. J Anesth Clin Res, 5(440), 2.

5. Francksen, H., Renner, J., Hanss, R., Scholz, J., Doerges, V., & Bein, B. (2009). A comparison of the i‐gel™ with the LMA‐Unique™ in non‐paralysed anaesthetised adult patients. Anaesthesia, 64(10), 1118-1124.

6. Weber, U., Oguz, R., Potura, L. A., Kimberger, O., Kober, A., & Tschernko, E. (2011). Comparison of the i‐gel and the LMA‐Unique laryngeal mask airway in patients with mild to moderate obesity during elective short‐term surgery. Anaesthesia, 66(6), 481-487.

7. Mitra, S., Das, B., & Jamil, S. N. (2012). Comparison of Size 2.5 i-gel™ with ProSeal LMA™ in anaesthetised, paralyzed children undergoing elective surgery. North American journal of medical sciences, 4(10), 453.

8. Jagannathan, N., Sommers, K., Sohn, L. E., Sawardekar, A., Shah, R. D., Mukherji, I. I., ... & Seraphin, S. (2013). A randomized equivalence trial comparing the i‐gel and laryngeal mask airway Supreme in children. Pediatric Anesthesia, 23(2), 127-133.

9. Theiler, L. G., Kleine-Brueggeney, M., Kaiser, D., Urwyler, N., Luyet, C., Vogt, A., ... & Unibe, M. M. (2009). Crossover comparison of the laryngeal mask supreme™ and the i-gel™ in simulated difficult airway scenario in anesthetized patients. Anesthesiology: The Journal of the American Society of Anesthesiologists, 111(1), 55-62.

10. Das, B., Mitra, S., Jamil, S. N., & Varshney, R. K. (2012). Comparison of three supraglottic devices in anesthetised paralyzed children undergoing elective surgery. Saudi journal of anaesthesia, 6(3), 224.

11. Bamgbade, O. A., Macnab, W. R., & Khalaf, W. M. (2008). Evaluation of the i‐gel airway in 300 patients. European Journal of Anaesthesiology (EJA), 25(10), 865

12. Wharton, N. M., Gibbison, B., Gabbott, D. A., Haslam, G. M., Muchatuta, N., & Cook, T. M. (2008). I‐gel insertion by novices in manikins and patients. Anaesthesia, 63(9), 991-995.

13. Middleton, P. M., Simpson, P. M., Thomas, R. E., & Bendall, J. C. (2014). Higher insertion success with the i-gel® supraglottic airway in out-of-hospital cardiac arrest: A randomised controlled trial. Resuscitation, 85(7), 893-897.

14. Hagberg, C., Bogomolny, Y., Gilmore, C., Gibson, V., Kaitner, M., & Khurana, S. (2006). An evaluation of the insertion and function of a new supraglottic airway device, the King LT™, during spontaneous ventilation. Anesthesia & Analgesia, 102(2), 621-625.

15. Gahan, K., Studnek, J. R., & Vandeventer, S. (2011). King LT-D use by urban basic life support first responders as the primary airway device for out-of-hospital cardiac arrest. Resuscitation, 82(12), 1525-1528.

16. Wyne, K. T., Soltys, J. N., O’Keefe, M. F., Wolfson, D., Wang, H. E., & Freeman, K. (2012). King LTS-D use by EMT-intermediates in a rural prehospital setting without intubation availability. Resuscitation, 83(7), e160-e161.

17. Frascone, R. J., Wewerka, S. S., Griffith, K. R., & Salzman, J. G. (2009). Use of the King LTS-D during medication-assisted airway management. Prehospital Emergency Care, 13(4), 541-545.

18. Guyette, F. X., Wang, H., & Cole, J. S. (2007). King airway use by air medical providers. Prehospital Emergency Care, 11(4), 473-476.

19. Baratto, F., Gabellini, G., Paoli, A., & Boscolo, A. (2017). I-gel O 2 resus pack, a rescue device in case of severe facial injury and difficult intubation. The American Journal of Emergency Medicine.

20. Häske, D., Schempf, B., Niederberger, C., & Gaier, G. (2016). i-gel as alternative airway tool for difficult airway in severely injured patients. The American journal of emergency medicine, 34(2), 340-e1.

21. Michalek, P., Hodgkinson, P., & Donaldson, W. (2008). Fiberoptic intubation through an I-gel supraglottic airway in two patients with predicted difficult airway and intellectual disability. Anesthesia & Analgesia, 106(5), 1501-1504.

22. Michalek, P., Donaldson, W., Graham, C., & Hinds, J. D. (2010). A comparison of the I-gel supraglottic airway as a conduit for tracheal intubation with the intubating laryngeal mask airway: a manikin study. Resuscitation, 81(1), 74-77.

23. Lutes, M., & Worman, D. J. (2010). An unanticipated complication of a novel approach to airway management. The Journal of emergency medicine, 38(2), 222-224.

24. Klein, L., Paetow, G., Kornas, R., & Reardon, R. (2016). Technique for exchanging the King Laryngeal Tube for an endotracheal tube. Academic Emergency Medicine, 23(3).

25. Carlson, J. N., Mayrose, J., & Wang, H. E. (2010). How much force is required to dislodge an alternate airway?. Prehospital Emergency Care, 14(1), 31-35.

26. Vithalani, V. D., Vlk, S., Davis, S. Q., & Richmond, N. J. (2017). Unrecognized failed airway management using a supraglottic airway device. resuscitation, 119, 1-4.

A debate of supraglottic proportions...

Which supraglottic airway should they be using?

What supraglottic airway is available within your EMS system? Why is it preferred and what are its advantages over the alternatives?

Read the Case Conclusion here.

Quality Assurance in Innovation: Drug Shortages, Cost and the Tale of Check & Inject NY

By Melinda Johnson, EMT-B

One could say that MacGyver is the patron saint of EMS. Prehospital professionals pride themselves on innovative solutions to patient care. Most frequently this takes the form of the work that goes into delivering a packaged patient to the right hospital in a timely manner no matter where, what time of day, and in what situation they originally presented. Less frequently, but no less importantly, this takes the form of innovative solutions to patient care on a system-level. Occasionally, this requires modification of a scope of practice limitation caught under statute or regulation.

Anaphylaxis is a potentially lethal multi-system allergic reaction triggered by an exaggerated immune response. The signs and symptoms of anaphylaxis include bronchospasm, urticaria, pruritis, angioedema, gastrointestinal symptoms (diarrhea, nausea, cramping), cardiac arrythmmias and hypotension [Figure 1]. These symptoms occur on a clinical continuum and can develop over time. Most anaphylaxis occurs in the prehospital environment.

Source: Simons, F. E. R., Ardusso, L. R., Bilò, M. B., El-Gamal, Y. M., Ledford, D. K., Ring, J., ... & Thong, B. Y. (2011). World allergy organization guidelines for the assessment and management of anaphylaxis. World Allergy Organiza… — Source: Simons, F. E. R., Ardusso, L. R., Bilò, M. B., El-Gamal, Y. M., Ledford, D. K., Ring, J., ... & Thong, B. Y. (2011). World allergy organization guidelines for the assessment and management of anaphylaxis. *World Allergy Organization Journal*, 4(2), 13.

Many studies have demonstrated that the treatment of choice for anaphylaxis is epinephrine [1]. Death from anaphylaxis occurs either through respiratory compromise or circulatory collapse. The treatment of anaphylaxis is about as time-critical as it gets. In a study of 202 patients who died of anaphylaxis in the UK from 1992 to 2001, onset of symptoms to death took 10-20 minutes for medications, 10-15 minutes for insect stings, and 25-35 minute for food exposures [2]. In two cases series comparing near-fatal and fatal anaphylactic reactions, a > 5 minute delay in epinephrine administration from time of onset of significant symptoms was closely associated with death [3,4]

Ideally, epinephrine is self-administered by patients via auto-injector as soon as severe symptoms occur. However, in many cases, patients either do not have their auto-injector or are having a first allergic reaction and need EMS to provide this potentially life-saving intervention. In the National Scope of Practice model, EMTs are allowed to help patients administer their own medication, but administration of IM epinephrine is left to the AEMT level. Studies published after these guidelines demonstrated that EMTs can administer epinephrine under appropriate circumstances given adequate training [5]. In 2011, NAEMSP published a position statement supporting administration of epinephrine by BLS providers, citing that it “is imperative that EMS providers have the capability to administer epinephrine in a timely fashion.” [6]

While the majority of states allow BLS providers to administer epinephrine, they require that it be administer in the form of an epinephrine auto-injector (EAI). Here in New York, the exponentially increasing cost in epinephrine auto injectors made it difficult for agencies to keep them stocked on their emergency vehicles. Despite the financial challenge posed by EAI, we knew that we couldn’t absolve such a lifesaving drug from our medical supplies. It would be unethical and harmful for our patients. We needed a solution (pun intended).

The Check & Inject NY project was born out of an increasing need for an alternative to the epinephrine auto injector. Several other states had used a lower-cost solution to the epinephrine auto-injector problem: syringe injectable epinephrine. A 2016 survey of all 49 states (excluding Texas because of variability in practice within the state) identified 13 states that allowed BLS providers to draw up epinephrine from an ampule and administer it by syringe [7]. At the time of the survey, 7 other states (including New York) were considering instituting training programs.

The idea of having basic EMTs draw up epinephrine seemed to be the best solution to the auto injector price hike. After reviewing the syringe-injectable epinephrine project developed by King County Medic One in Seattle Washington, we decided to have a specialized syringe manufactured to prevent dosing issues. We worked with CODAN Medical ApS, a company based in Denmark to develop a syringe with just two gradations on it, one for pediatric patients and the other for adult [Figure 2]. With this simple change, we avoided dosing errors throughout our project.

We quickly realized that given the distribution size of this project, it was unrealistic to put together and distribute all these kits ourselves. We entered a partnership with Bound Tree Medical to keep up with the demand for our kits state-wide. Through this partnership, we also provided a seamless transition to prevent further delay for our agencies to obtain the cost effective Check & Inject kits.

In EMS (and medicine in general), an intervention is only as useful as the training and quality assurance that accompanies it. The Check & Inject NY team created several different tools to be able to make this project successful. We created an entire training program for each agency participating to ensure each provider was refreshed on the use of epinephrine and when to choose adult over pediatric dosing. This training included a skills station in which each provider familiarized themselves with the syringe, the process of drawing up epinephrine, and the process of intramuscular administration. Additionally, students were provided pre and post tests, whose purpose was to evaluate the training and not necessarily the provider’s knowledge of the learning objectives. This was to ensure completeness of the training program so that we were able to provide uniform education not just to local participating agencies, but to agencies statewide.

As quality assurance was a key component to our pilot program, we established a physician phone line that enabled us to have an on-call physician 24/7 for each administration during the pilot program. Once the provider used the syringe epinephrine kit, they were to call this phone line to discuss with the physician about the administration process as well as potential concerns. The physicians then entered the data to a Research Electronic Data Capture database (REDCap) allowing the agency to maintain HIPPA compliance. Additionally, the phone alert itself, triggered a replacement kit to be sent to that agency at no additional cost.

In the active demonstration project phase, 638 agencies participated across the State. There were 83 administrations of check & inject epinephrine. All administrations were deemed indicated by physician consultation and none resulted in injuries for the patients or providers. It was found that kit usage was also utilized for asthma exacerbation. This lead our team to add asthma exacerbation as another Check & Inject kit indication. Interestingly, a provider reported that a patient stated that the syringe epinephrine kit was a less painful than an EAI as a method of receiving the medication.

On May 24, 2017, the project was formally adopted by the New York State Department of Health Bureau of EMS and Trauma (BEMSAT) with the support of the Commissioner of Health through the issuance of Policy 17-06. This was a tremendous achievement and expansion of the BLS scope of practice in New York State. The Check & Inject NY demonstration project is the largest of its kind ever undertaken in the State’s history, requiring collaboration on the part of many individuals. Many other states across the nation have inquired about our project and are looking to start ones of their own.

Patient care starts with basic life support and should not be limited by the outrageous and unnecessary hikes in medication cost. Rising drug costs, shortages, and evidence-based medicine require us to change our practice in order to do what is best for our patients. The importance of training and quality-control cannot be underestimated as we advance practice to ensure that our best-intentions are realized.

References

1. Kemp, S. F., Lockey, R. F., & Simons, F. E. R. (2008). Epinephrine: the drug of choice for anaphylaxis--a statement of the World Allergy Organization. World Allergy Organization Journal, 1(2), S18.

2. Pumphrey, R. (2004). Anaphylaxis: can we tell who is at risk of a fatal reaction?. Current opinion in allergy and clinical immunology, 4(4), 285-290.

3. Sampson, H. A., Mendelson, L., & Rosen, J. P. (1992). Fatal and near-fatal anaphylactic reactions to food in children and adolescents. New England Journal of Medicine, 327(6), 380-384.

4. Yunginger, J. W., Sweeney, K. G., Sturner, W. Q., Giannandrea, L. A., Teigland, J. D., Bray, M., ... & Helm, R. M. (1988). Fatal food-induced anaphylaxis. Jama, 260(10), 1450-1452.

5. Rea, T. D., Edwards, C., Murray, J. A., Cloyd, D. J., & Eisenberg, M. S. (2004). Epinephrine use by emergency medical technicians for presumed anaphylaxis. Prehospital Emergency Care, 8(4), 405-410.

6. Jacobsen, R. C., & Millin, M. G. (2011). The use of epinephrine for out-of-hospital treatment of anaphylaxis: resource document for the National Association of EMS Physicians position statement. Prehospital Emergency Care, 15(4), 570-576.

7. Brasted, I. D., & Dailey, M. W. (2017). Basic Life Support Access to Injectable Epinephrine across the United States. Prehospital Emergency Care, 1-6.

EMS MEd Editor: Maia Dorsett, MD PhD (@maiadorsett)

When it’s more complicated than a tweet: Door-to-Furosemide and EMS

by Sahar Morkos El-Hayek, MD

EMS MEd Editor Maia Dorsett, MD PhD (@maiadorsett)

This past summer, the results of the REALTY-AHF (Registry Focused on Very Early Presentation and Treatment in Emergency Department of Acute Heart Failure) study, a prospective observational cohort study of the management of patients presenting to the emergency for acute heart failure was published [1]. The one-liner conclusion – as summarized by tweets and online articles – was that early furosemide saves lives:

If early furosemide saves lives, why aren’t we giving it prehospital?

Because it doesn’t necessarily help and it has the potential to cause harm.

The REALITY- AHF was a prospective observational study that examined the association between door to furosemide (D2F) and all-cause-in-hospital-mortality. To be included in the study, patients had to be diagnosed with acute heart failure within their first three hours of admission to the ED. Patients who received furosemide within 60 minutes of arrival were assigned to the early treatment group. “Non-early” treatment was defined as furosemide administration at any time beyond the first hour. A total of 1291 patients met the inclusion criteria. 481 patients (37.3%) were classified as the early treatment group and 810 (62.7%) composed the non-early treatment group. Overall, the authors found a decrease in both in-hospital and 30-day mortality for patients who received furosemide within the first 60 minutes, (OR 0.36, 95% CI 0.19-0.71 and OR 0.52, 95% CI 0.28-0.96) respectively. Since the trial was not randomized, the authors attempted to control for confounding variables using propensity score matching and found similar results (OR 0.41, 95% CI 0.18-0.89 for in hospital mortality). The authors accounted for many variables - demographics, lab values – but not whether patients concurrently received therapies with proven outcome benefits such as nitroglycerin and ACE-inhibtors or Noninvasive Positive Pressure Ventilation( NIPPV )[2-5].

Variables accounted for in the Propensity Analysis by Matsue et. al. (Reference 1).

Patients who received earlier treatment were more likely to arrive by ambulance, had a more rapid onset of symptoms, and more severe congestive symptoms. As no other key interventions were examined – i.e. preload and afterload reduction – it is unclear whether “door-to-furosemide” time is simply a surrogate for the “door-to-rapid-recognition-and-treatment-of-acute-heart-failure” time.

The patients we care for in EMS are fundamentally different from the patients included in the REALTY-AHF study in one important way: they are undifferentiated. We care for patients with respiratory distress and shortness of breath, not an unequivocal diagnosis of acute heart failure. This is also true of the initial part of a patient’s stay in the emergency department. It is not always obvious at the time of presentation whether the etiology is acute heart failure, or rather a pulmonary embolism, Chronic Obstructive Pulmonary Disease (COPD), volume overload due to renal failure, sepsis from pneumonia or some combination of the above. Moreover, acute heart failure itself is not a homogenous disease. Most commonly heart failure is left-sided, but even then, it may be due to the heart’s decreased ability to pump blood into circulation (systolic heart failure) or incomplete filling during diastole [i.e diastolic heart failure or heart failure with preserved ejection fraction (HFpEF)]. Most emergency department patients with acute decompensated heart failure have preserved systolic function and are not overloaded in terms of total body volume [5]. Rather, these patients have a fundamentally vascular problem – one of an abrupt increase in afterload that results in acute decompensation. More importantly, although hypertensive, these patients may be euvolemic or even hypovolemic. In these cases, the treatment focuses on managing the flow of blood through system rather than eliminating fluid from the system. This is accomplished by NIPPV in the form of CPAP or BiPAP, high dose nitroglycerin, and ACE inhibitors [2-5].

Since many EMS and ED patients with acute decompensated heart failure are not volume overloaded, liberal use of diuretics may not be helpful and has the potential to be harmful [5]. Several studies have been published regarding prehospital furosemide administration, mainly examining the accuracy of paramedics’ working diagnosis of acute decompensated heart failure by comparing it to the final hospital diagnosis and studying the side effect profile and potential harm.

Jerome Hoffman and Susan Reynolds published a study in 1987 that evaluated the effect of prehospital furosemide on patient outcomes [6]. At the time of the study, paramedics in LA County were instructed to administer furosemide and morphine +/- nitroglycerin to patients with a clinical presentation consistent with pulmonary edema. Through clinical experience, the authors became concerned that morphine and furosemide led to clinically harmful respiratory depression and dehydration. They carried out a prospective sequential trial of therapies which included patients with shortness of breath as a presenting symptom and paramedic clinical suspicion for pulmonary edema and a SBP > 120. Patients received one of four treatment cocktails:

Group A: Sublingual nitroglycerin + 40 mg IV furosemide

Group B: 3 mg IV morphine + 40 mg IV furosemide

Group C: Sublingual nitroglycerin + 3 mg IV morphine + 40 mg IV furosemide

Group D: Sublingual nitroglycerin + 3 mg IV morphine [FUROSEMIDE-FREE]

Table 7 from Hoffman and Reynolds (Reference 6) . Group D represents the "Furosemide-free" group.

Each therapy could be repeated up to three times and there were 15 patients in each group. As this was not an intention-to-treat analysis, 2 patients were excluded who did not receive the prescribed treatment. Patients were evaluated for clinical deterioration or improvement in the prehospital arena, in the emergency department, and 12 hours into their admission. The study found that only 77% of patients had pulmonary edema in the emergency department with the most common alternative diagnosis being COPD exacerbation. They also found that excluding nitroglycerin and administering morphine increased intubation rates. Finally, their data suggested that prehospital furosemide administration lead to complications including arrhythmias due to hypokalemia, hypotension, increased tachycardia and need for fluid administration without clear evidence of benefit. The authors concluded that prehospital pharmacologic treatment of respiratory distress due to pulmonary edema should be limited to nitroglycerin.

In contrast, a multi-center retrospective study by Pan et. al. (2014) failed to identify an association between prehospital furosemide administration and serious adverse events (acute renal failure, intubation, vasopressors or death) [7]. The study included acutely ill patients 50 years and older with dyspnea who were diagnosed with acute heart failure in either the prehospital or hospital record. 330 patients were subdivided into three categories: Furosemide without heart failure (N=58), furosemide with heart failure (N=110), and no furosemide with heart failure (N = 162). They performed a linear regression to identify whether there was an association between furosemide use and outcome. The adjusted odds ratio for serious adverse event for patients receiving furosemide was 0.62 (95% CI 0.33 – 1.43) for patients with heart failure and 1.14 (95% CI 0.58-2.23) in those without. Similar to the REALTY-AHF study, the adjustments accounted for historical factors, but not differences in use of NIPPV or nitroglycerin which differed significantly between the groups (see Table).

34.8% of patients who received furosemide did not have a final ED diagnosis of acute heart failure. Other studies have found this proportion to vary anywhere between 15 – 36% [6-9]. This level of diagnostic accuracy is similar to emergency department physicians [10]. These represent a substantial proportion of critically ill patients who may be harmed by furosemide administration [9].

Take Home Points:

EMS cares for undifferentiated patients with shortness of breath. While expeditious furosemide therapy may benefit patients with acute heart failure due to volume overload, it may cause harm to the 15-36% of patients who are miscategorized as having acute decompensated CHF. EMS should continue to focus on appropriate use of therapies with significant benefit towards patient-centered outcomes, such as NIPPV, and leave consideration of door-to-furosemide time out of our protocols.

References

1. Matsue Y, Damman K, Voors A.A, et al. Time-to-Furosemide Treatment and Mortality in Patients Hospitalized With Acute Heart Failure. Journal of the American College of Cardiology Jun 2017, 69 (25) 3042-3051; DOI: 10.1016/j.jacc.2017.04.042

2. Sacchetti, A., Ramoska, E., Moakes, M. E., McDermott, P., & Moyer, V. (1999). Effect of ED management on ICU use in acute pulmonary edema. The American journal of emergency medicine, 17(6), 571-574.

3. Vital, F. M., Saconato, H., Ladeira, M. T., Sen, A., Hawkes, C. A., Soares, B., ... & Atallah, Á. N. (2008). Non-invasive positive pressure ventilation (CPAP or bilevel NPPV) for cardiogenic pulmonary edema. Cochrane Database Syst Rev, 3(3).

4. Levy, P., Compton, S., Welch, R., Delgado, G., Jennett, A., Penugonda, N., ... & Zalenski, R. (2007). Treatment of severe decompensated heart failure with high-dose intravenous nitroglycerin: a feasibility and outcome analysis. Annals of emergency medicine, 50(2), 144-152.

5. Scott, M. C., & Winters, M. E. (2015). Congestive heart failure. Emergency Medicine Clinics, 33(3), 553-562.

6. Hoffman, J. R., & Reynolds, S. (1987). Comparison of nitroglycerin, morphine and furosemide in treatment of presumed pre-hospital pulmonary edema. Chest, 92(4), 586-593.

7. Pan, A., Stiell, I. G., Dionne, R., & Maloney, J. (2014). Prehospital use of furosemide for the treatment of heart failure. Emerg Med J, emermed-2013.

8. Dobson, T., Jensen, J., Karim, S., & Travers, A. (2014). Correlation of paramedic administration of furosemide with emergency physician diagnosis of congestive heart failure.. Australasian Journal of Paramedicine, 7(3).

9. Wuerz, R. C., & Meador, S. A. (1992). Effects of prehospital medications on mortality and length of stay in congestive heart failure. Annals of emergency medicine, 21(6), 669-674.

10. Ackerman, R., & Waldron, R. L. (2006). Difficulty Breathing: Agreement of Paramedic andEmergency Physician Diagnoses. Prehospital Emergency Care, 10(1), 77-80.

Emergency Care and the Opioid Epidemic: Lessons from Dreamland

by Melody Glenn, MD

Last Wednesday, we met around a picnic table at Rotten City Pizza to discuss Sam Quinones’ Dreamland and the ways in which we as emergency providers can work to combat the worsening opioid epidemic.

Perhaps no one is more qualified to write such a captivating, multifaceted book on this international crisis than is Sam Quinones, who was a writer in Mexico for over a decade. Dreamland is a story of place, with each chapter rooted in a different city to illustrate how the factors unique to a specific location contributed to the growing problem. Each chapter also revolves around an individual character whose story represents a larger issue. Multiple story lines, initially seeming disparate and unrelated, all come together to form the overall narrative of addiction, and we realize how large and unwieldy the opioid epidemic has ballooned. Quinones shows how a perfect storm of changing business practices in heroin marketing and sales, socioeconomic forces in Xalisco, Mexico and the US rust belt, changing medical beliefs around pain and addiction, and pharmaceutical marketing and development coalesced to form the perfect storm in which opioid overdoses have nearly quadrupled over the last 20 years, now outpacing motor vehicle collisions as the number one cause of accidental death. Quinones focuses on several heavily impacted towns in Ohio, West Virginia, and Kentucky, which helps us make sense of the data regarding alarmingly high opioid abuse/death rates in this region.

In the emergency department, we are protagonists in this dark narrative. We frequently treat patients with opioid dependence, overdose, Hepatitis C, HIV, soft tissue infections, or traumatic injuries sustained while engaged in illicit activities. Unfortunately, we are partially to blame -- much of opioid dependence is iatrogenic. A study published in the New England Journal of Medicine earlier this year showed that a single opioid prescription from the ED may lead to long-term use (number needed to harm of 48 pts), and that this risk is greater if the patient is treated by a physician who prescribes relatively more opioids. Of course, we don’t see ourselves a nefarious drug pushes, or even as careless prescribers. Although we are not the highest prescribers, we come fairly close: according to one analysis, emergency medicine physicians prescribe almost 13% of all opioid prescriptions. Even if we aren’t directly getting our patients hooked, we are contributing to a flood of opioid pills onto the illicit market. In some states, there is more than 1 opioid prescription written for every person.

In the prehospital environment, the discussion seems to revolve more around acute overdoses and the use of naloxone to reverse them. Many EMS and police departments are expanding who they train to recognize and reverse an opioid overdose with naloxone -- it is no longer just paramedics administering this medication, but also first responders and law enforcement. However, there is increasing worry about the rising cost of treatment as overdoses increase in frequency. In one heavily affected town in Ohio, the local fire department estimates it will spend 50% more than its entire medication budget on naloxone because they respond to so many opioid overdoses; for a town of 48,791, they respond to about 4-5 overdoses a day, and this number continues to increase. Dan Picard, Middletown City Councilman, estimates that each overdose run costs the city $1,104. At this rate, they are not sure how they can continue to afford to provide emergency care to their community.

In addition to whether or not acute reversal is financially solvable, it is also unclear the long-term outcome of such reversal practices on patient outcomes. David Showalter, a sociology PhD candidate at UC Berkeley whose research focuses on opioid overdoses, and Dr. Andrew Herring, a physician double-boarded in emergency medicine and pain management, both believe that unless acute reversals are tied into more sustainable interventions, such as take-home naloxone kits, referrals to syringe exchanges, or referrals to medication-assisted treatment, acute reversals by field providers will have little impact on overall morbidity or mortality.

But that is where things get a little more controversial -- what kind of sustainable interventions are we willing to support? Some, including Quinones, argue for jail-based and abstinence-only recovery programs, with the goal of getting everyone 100% clean for the rest of their lives. Unfortunately, it’s rarely so simple. The data shows that fatal drug related overdoses usually increase after people leave jail or “drug-free” rehab. Although it may seem less palatable to some, harm reduction modalities seem to be the most effective in reducing heroin use and fatal overdose.

Harm reduction is based in the philosophy that we must meet patients where they are in order to reduce the morbidity and mortality associated with drug use. Harm reduction spans a large spectrum of practices, including syringe exchange, naloxone distribution to users and their friends/family, fentanyl testing kits (as many of the recent fatal OD’s have involved accidental consumption of fentanyl), medication-assisted treatment (MAT), and supervised injecting sites.

Various emergency departments and EMS systems are starting to distribute naloxone kits to those believed to be at risk of overdose, as well as to their family members and friends. Although some providers worry that providing naloxone encourages further opioid use, studies show the converse is true [1,2,3]. In Massachusetts, opioid overdose death rates are lower in communities with naloxone distribution programs than in similar communities without them[4]. In San Francisco and Chicago, mortality rates among IV drug users decreased after the introduction of naloxone programs [5,6]. Such programs are also considered a cost-effective intervention, in terms of quality-adjusted life years saved per cost spent [7]. So why aren’t more EMS services and ED’s giving prescriptions or naloxone take-home kits? In addition to cost, some may worry about liability if there is an overdose, but many states have enacted good samaritan regulations and third-party prescribing statutes to assuage such fears. Others may worry about providing insufficient training on when and how to use naloxone, but Dwyer et al showed that there are no significant differences in overdose response when training is provided and when it is not [8].

Another successful strategy to reduce heroin use and fatal overdose is through the use of medication-assisted treatment (MAT) with methadone or buprenorphine, which can somewhat be seen as preferred alternatives to illicit opioids. Sometimes, the use of these medications is just a bridge to abstinence, other times, they are taken for the rest of a person’s life. As these programs are so effective, the World Health Organization supports MAT as the first line treatment for opioid dependence for most patients.

Although a cochrane review found little difference between methadone and buprenorphine maintenance in terms of treatment retention and illicit opioid use, in Dreamland, Quinones does not paint the most favorable image of methadone clinics, blaming their dearth of counseling and therapy services on their profit-driven motive (p. 64), and describing them as targets for heroin dealers (p.63-66). Dr. Herring, who runs a pain clinic at Highland Hospital, says his patients describe methadone as more disabling than buprenorphine. When on methadone, they don’t feel clear-headed, and they have to go to a highly-stigmatized place every day to get their dose. Therefore, he believes that buprenorphine, which is just a partial opioid agonist, is the preferred agent. It can be prescribed by primary care providers (with a special waiver) out of their regular clinics, and patients can pick it up at their pharmacy like any other medication. It can also be be administered by emergency physicians, and as such, Dr. Hering has started a buprenorphine induction program out of his emergency department.

Dr. Kathy Vo, a toxicologist at Zuckerberg San Francisco General Hospital, cautions that we should not be so quick to discount methadone as an effective treatment modality. She believes that the daily clinic visits are vital to the success of some users. Nonetheless, as buprenorphine prescribing is more accessible to emergency physicians, it is bound to become another option in our toolbox for reducing opioid morbidity and mortality. As you do not need a special DEA waiver to provide induction doses for those in acute opioid withdrawal, some emergency physicians are administering buprenorphine in the ED and then referring their patients to other providers who have agreed to continue their patients on maintenance doses. Unfortunately, in many counties heavily hit by the opioid epidemic, there may not be any physicians with a buprenorphine waiver (DEA-x) available to follow these patients.

That’s where telemedicine comes in: Various start-up’s are offering telemedicine consults to patients in the ED and at home [9]. So via the same tablet that you use for your interpreter, or your stroke neurologist, you can also consult a pain specialist. And your patient can get their outpatient follow-up via their personal phone or computer.

What if your patient isn’t ready to stop using? This may be more common that we would like to think; Dr. Herring says that there is a prevailing mentality amongst providers that patients in the throes of a medical crisis related to opioids -- withdrawal, abscess, fall, overdose -- are in this perfect window for an intervention, for a “wake-up call.” In his experience, that’s not exactly the case. People in crisis often just want to make it through the crisis, and using opioids may be their more familiar method of coping. But even if they aren’t ready to get clean during that traumatic moment, don’t despair -- a different window of opportunity still exists -- one for engagement. Give them referral information about where they can access care. When they are ready, they’ll come.

Perhaps this is the most important take-home message for prehospital providers, that we can make a difference simply by providing our opioid-depedent patients with a list of local resources. In the same way that EMS systems have been responsible for creating trauma systems of care, we can start to forge a coheisve network among our emergency departments, harm reduction organizations, and outpatient MAT centers.

Are Emergency Physicians the EMS experts that many think they are?

by Clayton Kazan, MD MS FACEP

I suppose I am biased. Like many of the readers, I got my start in medicine working as an EMT on the UCLA EMS ambulance in college, and, I entered medical school with the intent to become an Emergency Physician. I have been actively involved in EMS since I was first bitten by "the bug" (yikes, 23 years), and I have always seen my understanding of the local EMS system as fundamental to my Emergency Medicine practice. When I was in residency, my classmates used to tease me (rightfully) as an EMS geek, but I always viewed EMS personnel as an extension of the ED, and knowing their protocols and practice was akin to knowing how our ED nurses manage our patients. EMS providers are as much a part of my treatment team as the ED nurse, tech, secretary, radiology, lab, etc. So, why don't more of our ED colleagues feel the same way? Why don't more of them take an active part in understanding the basics of the local EMS system in which they practice: scope of practice, treatment protocols, destination criteria, etc?

The American Board of Emergency Medicine (ABEM) and NAEMSP have taken the critical step of establishing a Board Certification in EMS, and I realize that our subspecialty is still in its infancy. Many of our physician colleagues, and, unfortunately, many of our fellow EP's still do not know that EMS Board Certification exists. What frustrates me is the lack of understanding by EP's that this whole knowledge set exists.

As an example, consider the interfacility transfer for STEMI patients. Our EMS system in Los Angeles County has had STEMI centers for more than 10 years. Since very early in our STEMI program, we recognized that our ED's could not get a private transport ambulance quickly enough to get STEMI patients to the cath lab quickly, so, by policy, they are permitted to call 911 to facilitate transfer to STEMI centers. Yet, we often find that our ED physicians start nitroglycerin and heparin drips on these patients prior to calling 911; with a clear lack of understanding that our paramedic scope of practice does not allow for such interventions.

Los Angeles County also allows for "911 re-triage" of trauma patients under specific circumstances in order to get them emergently evacuated from non-trauma hospitals to Trauma Centers. Despite the very clearly defined criteria, only about half of the calls we receive for 911 re-triage actually meet criteria. And, for the patients that do, we often find them receiving blood transfusions or IV infusions (propofol, etc) which are out of our scope of practice. When we share the EMS Agency policy with the ED administration, it is often apparent that they have little to no idea of its very existence.

Unfortunately, this lack of understanding is apparent even from California ACEP. In December 2015 and January 2016, Cal ACEP went on the warpath against Community Paramedicine and Alternative Destination projects citing a lack of data around their safety. Their stance was that people who call 911 are "actively seeking access to emergency care, where their EMTALA rights can be realized." But, Cal ACEP also noted that its mission is "to support emergency physicians in providing the highest quality care to all patients and to their communities." But, we (EMS Physicians) are Cal ACEP members and emergency physicians too, and these are our patients and communities. Prior to making its stance, Cal ACEP did not reach out to its EMS constituents for comment or input, and their stance demonstrates a lack of appreciation for the challenges faced by the EMS community. To their credit, since its publications, Cal ACEP has begun to engage with the EMS physician community.

So, how do we solve these issues? As the trailblazers in this new subspecialty, we need to pound the pavement and advocate for EMS. If we don't, then the Emergency Medicine (EM) groups will remain our proxy. We need to engage with groups on all sides and demonstrate the value that we bring to the table. This includes the EM groups, but also primary and urgent care, fire chiefs, firefighters, EMS groups, law enforcement, political groups, etc. We can have a loud voice, but only when groups remember to think of us, and they remember to think of us when they see us out there...so get out there and show up at meetings...until people start asking, "who is that guy that keeps showing up and eating our cookies and drinking our coffee?"

I was wrong. EMS is far more than an extension of the ED into the community. EMS is a mobile, community healthcare provider with its own patients, challenges, and values that sometimes transports sick patients to the ED. We care deeply for the communities we serve and the integrity of our EMS safety net. We fill a complex niche in community health that is completely distinct from the EM system. I am proud of my EMS Geekdom!

http://c.ymcdn.com/sites/californiaacep.org/resource/resmgr/docs/Lifeline/2016/Lifeline_Magazine_December_2.pdf (Page 4-6)

http://c.ymcdn.com/sites/californiaacep.org/resource/resmgr/docs/Lifeline/2017/Lifeline-Magazine_January_20.pdf (Page 10-15)

The EMS-ED Handoff: A Critical Moment in Patient Care

Screening & Treating: EMS and the Sepsis Care Continuum

by Elizabeth Odom, MD MPH

EMS MEd editor: Maia Dorsett MD PhD (@maiadorsett)

Case Scenario

It’s a hot summer day and EMS is dispatched to an old farmhouse on the edge of the town for a patient who has been ”generally weak” and now unable to get out of bed. Upon arrival, paramedics find a previously healthy 65 year old female who has had a productive cough for a week. She has had little oral intake for 3 days and her urine has been dark and low in volume. Her husband called EMS because she has become progressively more confused over the course of the day. Her vital signs are T 38.1 HR 96 BP 115/80 RR 23 O2 Sat 91%.

The patient is quickly loaded into the ambulance. An IV is placed and fluid bolus is initiated. Fingerstick blood sugar is within normal limits and an ECG demonstrates sinus rhythm. Given the semi-rural location, transport to the hospital will exceed 30 minutes.

The paramedic suspects sepsis. What is the role of EMS in sepsis screening and treatment? How should we best screen for sepsis in the prehospital environment? Beyond IV fluids, should EMS administer antibiotics?

Literature Review

Sepsis is a Time-Critical Diagnosis

Advancements in protocols for STEMI and trauma patients have drastically improved early identification and treatment [1,2]. Like STEMI and Trauma, sepsis is a time-critical diagnosis where early screening and intervention can impact outcome [3-6]. With a mortality rate of 18-50% depending on other risk factors, severe sepsis should be acted on as quickly as possible [7]. Septic patients who are transported by EMS are sicker and have a higher mortality than those who arrive via other means, so the effect of any delay in antibiotic administration in this population may be amplified [8]. Delays in care of even 1 hour after first medical contact have been shown to increase mortality in patients with severe sepsis [9-12] while antibiotic therapy within the first hour of severe sepsis recognition contributed to an 80% survival [13]. The rapid administration of broad spectrum IV antibiotics may save more lives than the administration of aspirin in acute MI and epinephrine in anaphylaxis [14].

Current literature suggests that sepsis is both underrecognized and undertreated in the prehospital setting [15-16]. The reasons are likely multi-factorial, but include knowledge gaps as well as poor prehospital performance of sepsis screening tools. A recently published survey study from Atlanta found that 24% of paramedics were unaware of evidence supporting early sepsis treatment [17]. Moreover, 73% of participating Emergency Physicians reported caring for patients with sepsis almost every shift, while 62% of EMS providers reported caring for patients with sepsis no more than occasionally. While there are multiple sets of criteria for diagnosing sepsis, sepsis screening tools have variable performance in the prehospital setting. MEWS (Modified Early Warning Score) and BAS 90-30-90 scores were 74% and 62% sensitive, while the Robson score has been found to be 75-90% sensitive [18-21]. The PRESS (prehospital severe sepsis) score to identify severe sepsis also has a sensitivity near 90%, but is rather complicated for prehospital use [22]. qSOFA was developed as a simple tool to prompt clinicians to consider sepsis and escalate therapy as appropriate [23,24]. However, recent studies have demonstrated that although very specific, it has extremely poor sensitivity for severe sepsis in the prehospital setting, predominantly due to absence of hypotension until after ED admission [25,26]. SIRS itself lacks specificity in the prehospital setting. Moreover, in the hospital, 12.1% of patients with documented severe infection causing end-organ dysfunction are SIRS-negative [27].

Some services have successfully introduced lactate meters to detect occult hypoperfusion to enable hospital notification of a need for early, aggressive intervention [6]. As lactate meters are cost-prohibitive for many services, an important alternative to is end-tidal capnography, which is more widely available and has increasing applications in the prehospital setting. More recently, end-tidal CO2 levels were found to correlate with lactate levels and mortality in the ED setting [28]. Incorporation of end-tidal capnography into a SIRS-based prehospital sepsis alert protocol had a sensitivity of 90% (95% CI 81-95%), a specificity of 58% (95% CI 52-65%), and a negative predictive value of 93% (95% CI 87-97%) for sepsis and severe sepsis [29] .

EMS Interventions and Antibiotic Administration

Although decreased time to from first medical contact to antibiotic administration has the potential to impact mortality for patients with severe sepsis and septic shock, few EMS systems have initiated the administration of antibiotics to septic patients in the prehospital setting. This is due to a number of complexities. First, as discussed above, sepsis may be difficult to diagnose, despite the numerous algorithms that have been presented. Second, blood cultures allow for targeted antimicrobial therapy and these should typically be drawn prior to antibiotic administration, which may be subject to contamination or be difficult to obtain in the prehospital setting. Third, logistics and costs behind carrying and administering antibiotic agents on ambulances limits feasibility without substantial evidence behind the routine administration of antibiotics in the field.

Some EMS systems have standardized sepsis protocols based on one or a combination of scales references above. The mainstay of these protocols is fluid resuscitation and prehospital notification [6]. A small number of EMS systems have begun to introduce antibiotic administration into their protocols for patients with severe sepsis. This has reduced time to antibiotic from an average of 131 minutes after first contact to 69 minutes [30]. Even with short transport times, antibiotics may be initiated prior to arrival, eliminating the wait time for a bed, to see a physician, to receive the drug from pharmacy, and for a nurse to administer it. In South Carolina, EMS has treated 650 septic patients according to this protocol and 59% have received antibiotics [31]. Patients with > 2 SIRS criteria and a Point of Care Lactate >2.2mmol/L were treated with IV or interosseous ceftriaxone 1 g is in cases of suspected pneumonia or piperacillin/tazobactam 4.5 g following obtainment of blood cultures. Contamination rate for EMS-obtained blood cultures was <6%. Preliminary data showing a reduction from 25.6% mortality vs 9.3% mortality for patients with sepsis within the hospital system. In Australia and New Zealand, the PASS (Paramedic Antibiotics for Severe Sepsis) study, a randomized trial in which paramedics following a similar protocol is underway [32].

One of the most commonly cited fears regarding prehospital antibiotic administration is that it will cause an in antibiotic resistance. Inappropriately prescribed antibiotics do indeed increase resistance [33]. “Inappropriate” antibiotic use in an undifferentiated patient is not straightforward to define. Programs will have to fairly be compared to ED-administered antibiotics (rather than hospital final-diagnosis) and the impact on patient-centered outcomes measured prospectively. Empiric antibiotics provided are consistent with those recommended by local agencies for bacterial sensitivity resistance patterns for each area [34]. Ideally, a randomized-controlled trial will be conducted as the true risks-benefits of EMS-initiated antibiotics is unclear.

Take Home

Sepsis is a time-critical diagnosis and EMS can play a key role in reducing time to intervention and impacting patient-centered outcomes. Currently, sepsis remains underrecognized and undertreated in the prehospital setting, largely due to knowledge gaps and poor performance of screening methods. Recently, end-tidal capnography has emerged as a tool to enhance prehospital sepsis screening. Some EMS agencies have introduced paramedic-initiated antibiotics with some success. Further research is needed to fully understand the risks and benefits of this approach, which may vary regionally due to transport times and subsequent hospital-based patient management.

References

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Synthetic Opioid Overdose: Practical Considerations for Emergency Medical Services

by Aurora Lybeck, MD and M. Riccardo Colella, DO

Abstract: First responders, including Emergency Medical Services (EMS), fire departments, and law enforcement officers (LEOs), are often the first to respond to suspected opioid overdoses. The heroin epidemic has been worsening throughout the US and Canada, from coast to coast and in every state and province. The recent increase in synthetic opioid abuse and heroin contaminants can raises additional safety concerns for first responders and strains local resources. We suggest an emphasis on provider safety including personal protective equipment (PPE) and awareness of potential first responder exposure. Patient care for suspected overdoses should focus on respiratory support, transporting patients refractory to initial scene care, and ensuring appropriate naloxone dosage and adequate supply on each responding unit. Synthetic opioids in a local area can create a surge in overdose calls that has the potential to overwhelm available emergency resources and supplies, akin to a mass casualty event. EMS systems may mitigate potential strain on local resources by awareness and monitoring of local epidemiologic patterns, preparation, and collaboration with local agencies.

Background: The number of heroin related deaths and overdoses have significantly increased over the past decade. Overdose deaths involving heroin more than tripled in the US from 2010 to 2014, and are anticipated to be even higher given the rapidly changing epidemic [1, 2, 3]. Numerous federal organizations such as The Center for Disease Control (CDC), Drug Enforcement Administration (DEA), National Drug Early Warning System (NDEWS), and the Canadian Centre on Substance Abuse (CCSA), continue to gather and report on these data as this epidemic burgeons. In 2016, the DEA declared prescription drugs, heroin, and synthetic opioids, such as fentanyl, the most significant drug related threat to the US.. Outbreaks of fentanyl and other synthetic opioids have contributed to surges in overdoses rates and deaths. In 2016 and early 2017, several EMS agencies experienced significant increases in overdose related call volumes. Multiple cities have witnessed overdose “outbreaks” which can overwhelm local EMS resources, akin to a mass causality event. For instance, in February 2017, EMS agencies in Louisville, Kentucky received 151 overdose calls within four days, with 52 of those calls occurring within 32 hours. [4] Medical examiner data from similarly affected areas reflects similar surges in overdose deaths, raising suspicion that fentanyl and other synthetic opioids may be at least partially to blame. [5, 6]. High-potency opiates require higher doses of naloxone for reversal. A retrospective study of NEMSIS data from 2012-2015 found that among patients receiving prehospital naloxone, the percent of patients receiving multiple doses increased from 14.5% in 2012 to 18.2 % in 2015, anoverall increase of 25.8 % suggesting increased infiltration of the opiod market by high-potency synthetics [7].

Fentanyl is considered 100 times more potent than morphine and 600 times more lipid soluble, subsequently increasing brain absorption. Illicitly produced synthetic opioids include non-pharmaceutical fentanyl, fentanyl analogs, and novel synthetic opioids [8]. Synthetic opioid overdose outbreaks have occurred historically on a smaller scale, as evidenced by the China White (3-methylfentanyl) in the US in the 1980’s [9] and several hundred fentanyl deaths across the US in the mid 2000’s [10,11]. The CDC reports a marked increase in deaths involving synthetic opioids since 2013 [2, 12]. Since Pharmaceutical fentanyl prescription rates (primarily fentanyl patches) remained relatively stable in comparison, the etiology of this surge is not prescription fentanyl. [12, 13]. Synthetic opioids are often found as a heroin contaminant or are sold in pill form [14, 15]. Hundreds of thousands of counterfeit pills have been entering the US and Canadian drug market, many of which contain fentanyl and other synthetic opioids, some at lethal doses in a single pill [12-18].

The fentanyl analog carfentanil is considered 10,000 times more potent than morphine and 100 times more potent than fentanyl [5, 6, 19], and is reported in medical examiner overdoses cases across the US and Canada. In 2002, an unknown aerosolized “gas” was used by Russian special operations forces in an attempt to rescue 800 hostages held in a theater by Chechnan rebels. Sadly, at least 125 hostages were killed, and years later carfentanil and remifentanil were positively identified as likely agents in post-mortem samples [20]. Other synthetic opioids including various fentanyl analogs, (such as MT-45, AH-7921 and an isomer U-47700) are present in the illicit marketplace and have all been confirmed in deaths in the US, Canada, and Europe [21-24]. Once novel synthetic drugs appear in the market, there is often a significant time delay to the development of an assay for identification in post-mortem samples. By the time the chemical is identified with reliability, either from post mortem samples or seized drug samples, the synthetic drug manufacturers often have already flooded the market with a new compound. Consequently, first responders may encounter either an affected patient or a drug exposure in the field before it has been identified.

Provider Safety and Personal protective equipment (PPE)

The most commonly used PPE for first responders includes nitrile gloves and occasionally eye protection, escalating to other types of PPE as situationally indicated. In a 2017 descriptive surveillance study, data collected from 572 EMS workers who sought treatment in emergency departments (EDs) between 2010-2014 demonstrated that exposures to harmful substances were the second leading occupational injury (behind strains and sprains). The authors recommended new and enhanced efforts to prevent EMS worker injuries and exposures to harmful substances [25]. The concept of evolving and improving our use of PPE is not new to healthcare providers. Diseases such as Ebola and SARS have spurred additional training and use of PPE, and the use of PPE should be continually readdressed in the face of new threats to provider safety.

The DEA released a warning in June 2016 to the police and public regarding fentanyl exposures after two law enforcement officers (LEOs) experienced overdose symptoms after exposure to airborne particulate from a “tiny amount” of white powder. This warning was later expanded to include all first responders, with a guide for prehospital providers released in Jun 2017 [26, 27]. Heroin found in the white powder form (predominantly, with some regional variability) and is visually indistinguishable from most synthetic opioids (1). Fentanyl and other synthetic opioids in the white powder form may put first responders at risk by mucous membrane contact, inhalation of airborne particulate, and potentially skin contact. Toxic doses of carfentanil in particular pose a significant risk to first responders in small amounts, some as little as a few grains of salt. The Acting DEA Administrator stated in reference to synthetic opioids: “I hope our first responders- and the public- will read and heed our health and safety warning. These men and women have remarkably difficult jobs and we need them to be well and healthy” [19].

With increasing concern for first responder safety and exposures, the Justice Institute of British Colombia, in conjunction with the Royal Canadian Mounted Police (RCMP), British Colombia Emergency Health services, and Vancouver Fire Rescue services, and other collaborating services created an innovative website at www.fentanylsafety.com. Included are resources for all levels of first responders outlining specific considerations for LEOs, firefighters, EMS, and Hazmat personnel. Within the EMS recommendations is a guide specific for fentanyl/synthetic overdose education, treatment guidelines, field risk assessment, donning and doffing PPE including N95 masks, and protocol recommendations for self-administration of naloxone in the event of symptomatic exposure. NIOSH, the National Institute for Occupational Safety and Health, provides similar PPE recommendations for first responders, found at www.cdc.gov/niosh/topics/fentanyl/risk.html. Though exposures may be uncommon, the prehospital environment can be unpredictable and providers may unintentionally encounter substances while caring for patients. First responders should be intimately aware of risk for contact with, disturbing, or aerosolizing any powders on patients, their clothing, and surroundings. If such substances are on or near the patient, first responders should at minimum add respiratory precautions such as facemasks to routine PPE, and consider NIOSH recommendations for full PPE. As always, scene safety remains paramount.

Respiratory support

Synthetic opioids overdoses should be treated initially the same as all patients with respiratory failure and/or suspected opioid overdoses with a pulse, primarily with effective Bag-Valve-Mask (BVM) ventilations. Ensuring an open airway, providing respiratory support, and monitoring circulation remain cornerstones of patient care for all levels of EMS providers. Nasal or oral airway adjuncts and oxygen administration to correct hypoxemia should also be used when indicated. Almost one quarter of synthetic opioid overdose patients described in one hospital based case series required advanced respiratory support for persistent hypoxemia despite high doses of naloxone, and repeat respiratory arrest after cessation of naloxone infusion [14]. While the current focus for lay persons and law enforcement is rapid naloxone administration for suspected opioid overdoses, EMS providers are experts in the “ABCs”. A full patient assessment, high quality basic skills such as use of airway adjuncts, BVM, and respiratory support is imperative.

Naloxone

Naloxone is a high affinity mu-opioid receptor antagonist which acts on the central nervous system. It can be given to suspected opioid overdoses to reverse respiratory depression in the prehospital setting. For routine suspected opioid overdose, there are no definitive studies that have determined the optimal dose of naloxone to administer. Recommendations for initial dose can vary 10-fold based on reference and medical specialty. In general, emergency medicine and anesthesia references suggest higher doses (0.4mg) while medical toxicology and general medicine references suggest lower doses (0.04mg) [28]. The naloxone nasal atomizer devices currently in use by most first responders and bystanders is delivered in either 2mg or 4mg single dose sprays. Intranasal (IN) naloxone has an approximate bioavailability of only 4%, significantly lower than intramuscular (IM) and intravenous (IV) naloxone [29]. One prehospital study found that 2mg IN naloxone was not inferior to 0.4mg IV naloxone at reversing opioid induced apnea or hypopnea [30].

There is some concern that following naloxone administration and reversal of opioid overdose, patients may have adverse events such as pulmonary edema, precipitation of withdrawal symptoms, vomiting, or aspiration pneumonitis. In a one year prospective study in Norway, EMS witnessed vomiting in only 9% of patients who received prehospital naloxone [31]. A retrospective study in Pittsburgh found a lower rate of adverse events following naloxone administration with vomiting in only 0.2% of patients [32]. Novel synthetic opioid overdose cases have demonstrated a variety of adverse events during or after naloxone administration, including pulmonary edema and diffuse alveolar hemorrhage [14, 21], though the exact incidence is not known. EMS and first responders should also be aware of the potential safety risk of unmasking of other drug intoxications (methamphetamine, cocaine, or other stimulants) leading to behavioral disturbances. LEO training in naloxone administration has been generally well received and initial studies also report low rates of adverse events [33-35]. Overall, prehospital naloxone administration for suspected opioid overdose is considered safe, though the impact of synthetic opioids on the safety profile is unknown.

Naloxone administered to patients with synthetic opioid overdoses may require multiple doses. During known fentanyl overdose outbreaks, patients have required up to 14mg of naloxone to reverse respiratory and CNS depression [10, 36, 37]. In the prehospital environment, resources can be limited, and a single responding unit or even an entire region may not regularly stock large quantities of naloxone for single patient use. Naloxone supply can be particularly strained during events such as multiple overdose calls for a single responding unit or a multi-day drug overdose outbreak within a single system or area. In a case series of 18 patients, many of whom required naloxone infusions after exposure to fentanyl-adulterated pills, an entire hospital supply of naloxone was depleted and required emergency delivery to replete supply. 83% of patients who had either witnessed or themselves overdosed in the preceding six months reported that two or more doses of naloxone (most commonly used 2mg IN) were required before any response in suspected fentanyl overdoses [38]. Since novel synthetic opioids may have varied street concentrations, potencies, and receptor affinities, the actual dosage of naloxone that may be required to restore adequate spontaneous respirations may be unpredictable. This further emphasizes the role of respiratory support and transport particularly for patients who do not respond adequately to initial attempts at reversal on scene.

Transport

While some studies have failed to demonstrate increased mortality after opioid overdose reversal in the field [39, 40], those who may have overdosed with known or suspected long acting opioids, synthetic opioids, or those requiring repeated doses of naloxone benefit from transport to the nearest emergency department [8, 14]. The safety of refusal of transport after a suspected synthetic opioid overdose has not been established. If spontaneous respiratory drive has not returned after initial resuscitation attempts, EMS should consider transport rather than staying for extended scene times to administer repeated doses of naloxone. En route patient care should include continued reassessment, monitoring, and ongoing respiratory support with repeated administration of naloxone titrated to return of adequate spontaneous respirations, per local protocols.

Awareness of local patterns, collaboration, and community engagement

Synthetic opioids have the potential to overwhelm available emergency resources and supplies, akin to a mass casualty event. EMS systems may mitigate potential strain on local resources by monitoring local epidemiologic patterns, preparing for outbreaks, and collaborating with local agencies, including call centers, law enforcement agencies, EMS/fire departments and EDs. EMS data is particularly well suited for surveillance of suspected overdose patterns as it is geographically indexed and can be collected in near real time [41, 42]. Initial suspicion and tracking of synthetic opioid patterns can involve local EDs, medical examiners, toxicologists, and law enforcement. By sharing knowledge of local trends, all collaborators can stay abreast of the epidemic.

EMS and other first responders are well positioned for a critical role in intervention and prevention, and can provide a unique perspective for community engagement. On-scene interaction with the patient and/or family provides a potentially impactful opportunity to provide resources and support. EMS systems should consider novel strategies for combating the underlying opioid epidemic, including providing on-scene resources, take home naloxone rescue kits, encouraging any local resource utilization including medication assisted treatment (MAT), role of community paramedicine, and other opioid reduction programs.

Additional Resources:

The DEA video with LEO personal accounts of their exposure
Canada's fentanyl safety website
NIOSH recommendations for prehospital PPE
DEA: "Fentanyl, a briefing guide for first responders"

Special thanks to Brooke Lerner, PhD and Jill Theobald, MD

References:

1. United States Drug Enforcement Administration National heroin threat assessment summary—updated. (June 2016). Retrieved Feb 25, 2017. www.dea.gov/divisions/hq/2016/hq062716attach.pdf

2. Rudd RA, Seth P, David F, Scholl L: Increases in Drug and Opioid Involved Overdose Deaths-United States, 2010-2015. December 30, 2016 MMWR Morb Mortal Wkly Rep. 2016;65(50-51):1445-1452

3. Deaths Involving Fentanyl in Canada, 2009–2014. Canadian Centre on Substance Abuse. http://www.ccsa.ca/Resource%20Library/CCSA-CCENDU-Fentanyl-Deaths-Canada-Bulletin-2015-en.pdf. Published August 2015. Accessed February 25, 2017

4. Sonka, Joe. (2017). Fentanyl was main driver of Louisville’s surge in drug overdose deaths in 2016. [news release] Insider Louisville. February 28, 2017. Accessed May 24, 2017. https://insiderlouisville.com/metro/fentanyl-was-main-driver-of-louisvilles-surge-in-drug-overdose-deaths-in-2016/

5. Ohio Hamilton County Heroin Coalition: Public Health Announcement: Synthetic Opioid Carfentanil Found in Local Drugs. December 5, 2016. Retrieved Feb 25, 2017 www.hamiltoncountyhealth.org

6. Medical Examiner Public Health Warning Deadly Carfentanil Has Been Detected in Cuyahoga County [news release]; Cuyahoga County Medical Examiner; August 17, 2016. Accessed Feb 25, 2017, http://executive.cuyahogacounty.us/en-US/ME-Public-Health-Warning.aspx

7. Faul, M., Lurie, P., Kinsman, J. M., Dailey, M. W., Crabaugh, C., & Sasser, S. M. Multiple Naloxone Administrations Among Emergency Medical Service Providers is Increasing. Prehospital Emergency Care, 2017; 1-8

8. Lucyk SN, Nelson LS. Novel Synthetic Opioids: An Opioid epidemic within an opioid epidemic. Ann Emerg Med. 2017 Jan;69(1):91-93

9. Martin M, Hecker J, Clark R, et al. China White epidemic: an eastern United States emergency department experience. Ann Emerg Med. 1991;20(2):158-164

10. Schumann H, Erickson T, Thompson T et al. Fentanyl epidemic in Chicago, Illinois and surrounding Cook County. Clin Toxicol (Phila). 2008;46(6):501-506

11. Boddinger D. Fentanyl-laced street drugs “kill hundreds”. Lancet 2006;368:569-570

12. Gladden RM, Martinez P, Seth P. Fentanyl law enforcement submissions and increases in synthetic opioid involved deaths-27 states, 2013-2014. MMWR Morb Mortal Wkly Rep August 26, 2016;65:837-43

13. Fentanyl and Fentanyl Analogs. National Drug Early Warning System (NDEWS) Special Report. https://ndews.umd.edu/sites/ndews.umd.edu/files/NDEWSSpecialReportFentanyl12072015.pdf Published December 7, 2015. Accessed February 25, 2017

14. Sutter ME, Gerona R, Davis M, et al. Fatal fentanyl: One pill can kill. Acad Emerg Med. 2017 Jan;24(1):106-113

15. Armenian P, Olson A, Anaya A, Kurtz A, Ruegner R, Gerona RR. Fentanyl and a Novel Synthetic Opioid U-47700 Masquerading as Street “Norco” in Central California: A Case Report. Ann Emerg Med 2017 Jan;69(1):87-90

16. United States Drug Enforcement Administration Counterfeit prescription pills containing fentanyls: A global threat. (July 2016). Retrieved Feb 25, 2017, from www.dea.gov/docs/Counterfeit%20Prescription%20Pills.pdf.

17. Novel Synthetic Opioids in Counterfeit Pharmaceuticals and other Illicit Street Drugs. Canadian Centre on Substance Abuse. http://www.ccsa.ca/Resource%20Library/CCSA-CCENDU-Novel-Synthetic-Opioids-Bulletin-2016-en.pdf Published June 2016, Accessed February 25, 2017

18. CDC health update: influx of fentanyl-laced counterfeit pills and toxic fentanyl-related compounds further increases risk of fentanyl-related overdose and fatalities. (Aug. 25, 2016.) U.S. Centers for Disease Control and Prevention. Retrieved Feb 25, 2017, from https://emergency.cdc.gov/han/han00395.asp.

19. Drug Enforcement Administration Report: DEA Issues Carfentanil Warning to Police and Public. September 22, 2016. Accessed Feb 25, 2017. https://www.dea.gov/divisions/hq/2016/hq092216.shtml

20. Riches JR, Read RW, Black RM, Cooper NJ, Timperley CM. Analysis of clothing and urine from Moscow theatre siege casualties reveals carfentanil and remifentanil use. J Anal Toxicology 2012 Nov-Dec;36(9):647-56

21. Helander A, Backberg M, Beck O. Intoxication involving the fentanyl analogs acetylfentanyl, 4-methoxybutyrfentanyl and furanylfentanyl: results from the Swedish STRIDA project. Clinical Toxicology 2016;54(4):324-32

22. Mounteney J, Giraudon I, Denissov G, Griffiths P. Fentanyls: Are we missing the signs? Highly potent and on the rise in Europe. International Journal of Drug Policy (2015) 26:626-631

23. Mohr AL, Friscia M, Papsun D et al. Analysis of Novel Synthetic Opioids U-47700, U-50488 and furanyl fentanyl by LC-MS/MS in Postmortem Casework. J Anal Toxicol 2016;40(9):709-717

24. Coopman, V, Blanckaert P, Van Parys G, et al. A case of acute intoxication due to combined use of fentanyl and 3,4-dichloro-N-[2-(dimethylamino)cyclohexyl]-N-methylbenzamide (U-47700). Forensic Sci Int 2016; 266-68-72

25. Reichard AA, Marsh SM, Tonozzi TR et al. Occupational Injuries and Exposures among Emergency Medical Services Workers. Prehosp Emerg Care 2017 Jan 25 [Epub ahead of Print]

26. Drug Enforcement Administration Report: DEA Warning to Police and Public: Fentanyl exposure Kills. June 10, 2016. Accessed Feb 25, 2017. https://www.dea.gov/divisions/hq/2016/hq061016.shtml

27. Drug Enforcement Administration: Fentanyl, A Briefing Guide for First Responders. Accessed June 12, 2017. http://dig.abclocal.go.com/wls/documents/DEA_Fentanyl_Publication.pdf

28. Connors NJ, Nelson LS. “The Evolution of Recommended Naloxone Dosing for Opioid Overdose by Medical Specialty.” J Med Toxicol. 2016 Sep;12(3):276-81.

29. Dowling J, Isbister GK, Kirkpatrick CM, Naidoo D, Graudins A. “Population pharmacokinetics of intravenous, intramuscular, and intranasal naloxone in human volunteers.” Ther Drug Monit. 2008 Aug;30(4):490-6.

30. Merlin MA, Saybolt M, Kapitanyan R et al. Intranasal naloxone delivery is an alternative to intravenous naloxone for opioid overdoses.

31. Belz D, Lieb J, Rea T, Eisenberg MS. “Naloxone use in a tiered-response emergency medical services system.” Prehosp Emerg Care. 2006 Oct-Dec; 10(4):468-71.

32. Buajordet I, Naess AC, Jacobsen D, Brørs O. Adverse events after naloxone treatment of episodes of suspected acute opioid overdose. Eur J Emerg Med. 2004 Feb;11(1):19-23.

33. Ray B, O’Donnell D, Kahre K. Police officer attitudes towards intranasal naloxone training. Drug Alcohol Depend 2015 Jan 1;146:107-10

34. Purviance D, Ray B, Tracy A, Southard E. Law enforcement attitudes towards naloxone following opioid overdose training. Subst Abus 2016 Aug 11:1-6 [Epub ahead of print]

35. Fisher R, et al. Police officers can safely and effectively administer intranasal naloxone. Prehosp Emerg Care 2016;20(6):675-80.

36. Boyer EW. Management of opioid analgesic overdose. New England Journal of Medicine. 2012;367(2):146-155

37. Solomon, Ranee. A 20-year-old woman with severe opioid toxicity. Journal of Emergency Nursing, April 2017 [Epub ahead of Print]

38. Somerville NJ, O’Donnell J, Gladden RM, et al. Characteristics of Fentanyl Overdose- Massachusetts, 2014-2016. MMWR Morb Mortal Wkly Rep 2017;66:382-386

39. Wampler DA, Molina DK, McManus J, et al. No deaths associated with patient refusal of transport after naloxone-reversed opioid overdose. Prehosp Emerg Care. 2011;15(3):320–324.

40. Kolinsky D, Keim SM, Cohn BG, Schwarz ES, Yealy DM. Is a prehospital treat and release protocol for opioid overdose safe? The Journal of Emergency Medicine. 2017;52(1):52-58.

41. Garza, A and Dyer, S. EMS Data Can Help Stop the Opioid Epidemic. JEMS, Nov 2016. Accessed Feb 25, 2017.

42. Moore, PQ, Weber J, Cina S, Aks S. Syndrome surveillance of fentanyl-laced heroin outbreaks: Utilization of EMS, Medical Examiner, and Poison Center databases. Am J Emerg Med 2017 May 8

When You're Stuck in the Middle: Caring for Residents During Major Events.

by Tom Grawey, DO

Case Scenario: It is the first couple hours of your shift on the rig while you're working on some chores at the station. Your partner mentions that his wife is running her first marathon today which happens to pass through your coverage area. While some of your colleagues are scattered throughout the race path, you are ready to respond to a call from those not participating in today's activities.

A few minutes later a call comes in from the dispatcher for a 68 y/o male who is having chest pain a few blocks away. While on any other day this would be a pretty routine occurrence, given the race, you and your partner take a few extra minutes to map out a route to the scene with the current road closures in place. With all of the detours and traffic congestion you realize it will probably take an extra 5-10 minutes to get to the scene. A few questions start to run through your head:

Do residents living in the area of a mass gathering event receive a different level of care when an event is taking place?

How much is caring for this population discussed during the planing stages of the event?

What are some strategies that can be used to mitigate the challenges of providing medical care to non-participants who experience illness during a mass gathering in their neighborhood?

Literature Review:

During a mass gathering the daily EMS needs of the community do not stop. Undoubtedly one of the biggest challenges when planning an event is trying to have as little impact on the residents living in the area as possible. Road closures, eliminated parking spots, large amounts of pedestrians walking through a neighborhood and a redirection of the attention of first responders are just some inconveniences that residents experience during a marathon or similar activity.

A particular focus of our profession is the effect that mass gatherings have on access to prehospital medicine. As people who are helping plan the emergency response to an event, it is responsibility of EMS to ensure that participants, attendees and residents of the community all have appropriate access to medical care should they need it. A recent study was published in the New England Journal of Medicine entitled “Delays in Emergency Care and Mortality during Major U.S. Marathons” evaluated whether there are delays in care for nonparticipants with a medical emergency who live close to marathon routes. [1]

This study analyzed Medicare data to identify patients who were hospitalized for acute myocardial infarction (AMI) or cardiac arrest among Medicare beneficiaries in 11 cities that hosted large marathons over a 10 year period from 2002-2012. The idea was that this cohort would be unlikely to be running the marathon. For this population, 30 day mortality was compared among three groups - those near the race hospitalized on the same day as the marathon, those near the race hospitalized on the same day of the week either 5 weeks before or 5 weeks after the marathon, and those with these conditions who were hospitalized on the same day as the marathon but in a surrounding zip code that was not affected by the race path. In addition to patient outcomes, the study reviewed ambulance transport data to answer two questions - whether transport times varied before or after noon on marathon days, and whether transport times varied on marathon vs non marathon dates.

In total, the study examined 1145 hospitalizations for AMI or cardiac arrest on marathon dates in affected hospitals compared to 11074 on non marathon dates in the 10 weeks surrounding the event. Patient age, sex, race and past medical history were statistically similar on all dates. Despite the race taking place there was no difference in daily frequency of hospitalizations for these complaints between marathon and non-marathon dates.

The research team found that 30 day adjusted mortality was higher among those admitted to marathon-affected hospitals on marathon dates than on non-marathon dates (28.6% [95% CI, 26.1 to 31.3] vs 24.9% [95% CI 24.1 to 25.6], absolute adjusted risk difference 3.7% [95% CI, 1.1 to 6.4]). In control hospitals, it was found that adjusted mortality was similar on marathon (25% [95% CI, 23.6 to 26.4]) and non marathon dates (24.7% [95% CI, 24.3 to 25.2]). Transport times increased by an average of 4.4 minutes on marathon vs non marathon dates (95% CI, 1.3 to 7.5 p=0.0005) even though mileage traveled was similar.

When trying to account for possible causes of increase in mortality, further analysis revealed that frequency of hospitalizations, distribution of home zip codes of all patients, CABG, PCI or those receiving circulatory support did not differ in either group and it was concluded that differences in morality were not attributed to out-of-towners, hospital staffing or patients forgoing care. Of note, a high percentage of patients presenting with AMI in regions affected by a marathon had concurrent cardiac arrest on race than on non race days (5.1% vs 2.6%, absolute difference, 2.5%; 95% CI, 1.4 to 3.5; P<0.001) while this was not a significant finding in control hospitals.

A Discussion of the case raised a few key points:

"A well planned marathon route should interrupt as little of city traffic as possible for as short a time as possible. For example, the route on one of our events, the Milwaukee Running Festival, was recently modified because it landlocked a section of the city for too long. I would imagine that any large event or other disruption (construction, parades, arena sporting events, Summerfest) disrupt the flow of traffic enough to delay emergency medical care, but I would argue that the health and lifestyle benefits of these events outweighs the negatives. Nevertheless, the lesson on the importance of careful planning to ensure as little community disruption as possible is noted.” – Ben Weston, MD

Dr. Weston mentions something that isn’t discussed in the case or the NEJM Article – the benefits of the race to the participants. The decrease in heart disease associated with regular exercise is well known and published countless times in the literature. Certainly training for a marathon far exceeds the current CDC recommendations of just over 20 minutes a day of moderate-intensity aerobic activity and 2+ days a week of muscle strengthening activities. [2] While the personal choice (and health limitations) preventing some from participating in a race should not be held against them there is a greater good in mind when a community plans a marathon and as with any medical decision a risk/benefit approach must be used when planning an event.

Take home: Any event large enough to cause road closures and an influx of people is likely to cause delays in care to nonparticipants. This study shows that in the case of large marathons, these obstacles may worsen outcomes for residents living in race affected areas. EMS physicians and race medical directors must remain vigilant to ensure that a large event can accomplish its goals while creating as few interruptions and delays in medical care to nonparticipants as possible.

References:

1. Jena AB, Mann NC, Wedlund LN, Olenski A. Delays in emergency care and mortality during major US marathons. N Engl J Med. 2017;376:1441-1450. doi: 10.1056/NEJMsa1614073

2. Physical Activity Guidelines Advisory Committee. Physical Activity Guidelines Advisory Committee Report, 2008. Washington, DC: U.S. Department of Health and Human Services, 2008.

Articles in Review: The 2018 LLSA for EMS

The 2018 EMS Subspecialty LLSA Articles have been released by ABEM. The Communications Committee has put together the following review of all 12 articles to keep you up to date and ready for the test when it eventually comes out...

1. Brown JB et al. Not all prehospital time is equal: influence of scene time on mortality.J Trauma Acute Care Surg Jul 2016;81(1):93-100.

Reviewed by Maia Dorsett, MD PhD, @maiadorsett

Background & Objectives: Given that trauma is a time –sensitive disease, minimizing prehospital time may be beneficial to trauma patients. Most studies have not linked increased prehospital time with worse trauma outcomes. With the overall goal of identifying modifiable prehospital factors that may improve trauma outcomes, the objective of the study was to evaluate the association of prehospital time patterns with mortality.

Methods: The study was a retrospective review of data from the Pennsylvania Trauma Registry. Inclusion criteria were all patients 16 years and older who were transported by EMS with a total prehospital time (TPT) of 20 minutes or longer between Jan 2000 – June 2013. Patients were excluded if they were transported from another hospital or if prehospital time data were missing. Total prehospital time was divided into Response (notification to arrival), Scene (arrival to leaving for hospital), and Transport (scene to hospital). In order to control for the variability of “raw” prehospital times due to EMS system characteristics, the authors evaluated the relative proportion that each interval contributed to the TPT. A time interval was classified as prolonged If it contributed to > 50% of TPT.

After matching for TPT, a logistic regression model was used to determine the association of mortality with PH time pattern, controlling for confounders such as age, sex, race, co-morbidities, mechanism, transport mode, PH provider level (ALS vs. BLS), IVF volume, PH and admission VS, ISS, severe head injury, and blood transfusion in the ED.

Key Results: Out of 164,471 patients included in the study, only 2% had a prolonged response time, while 19% had a prolonged scene time and 31% had a prolonged transport time. Prolonged scene time was associated with a 21 % increase in mortality (AOR 1.21, 95% CI, 1.02-1.44, p = 0.03). Prolonged response time and transport time were not associated with increased mortality [AOR 1.16, 95% CI 0.83-1.3, p = 0.38 for response; AOR 0.82, 95% CI 0.65 – 1.04, p = 0.11 for transport]. This was consistent for patients with both blunt and penetrating trauma, although was more pronounced for patients with penetrating trauma who more commonly required emergent operative intervention. The effect was also more pronounced when overall prehospital time increased.

To further break down contributing factors, the authors evaluated the contribution of intubation and extrication to mortality. They found that prehospital intubation was associated with an increased risk of mortality (AOR 4.49, 95% CI, 3.48-5.78) and contributed on average 6 min 22 seconds to scene time. Extrication was also associated with mortality (AOR 1.40, 95% CI 1.19-1.65, p < 0.01) and extended scene time by 4 min 30 seconds on average. Together, they mediated 60.5% of the total effect of prolonged scene time on mortality in the risk-adjusted model. However, the more extrications or intubations an EMS agency performed, the less dramatic the effect on mortality. In patients with GCS < 8, there was an association between prehospital intubation and mortality if patients were transported by ground (AOR 2.52, 95% CI, 1.95 – 3.26, p < 0.01) but not if they were transported by helicopter (AOR, 1.26; 95% CI 0.92 – 1.73).

Take Home: Prolonged scene time is associated with increased mortality of trauma patients. Prehospital intubation and extrication mediate this effect significantly, although less so when EMS agencies have more experience in either procedure.

2. Weaver MD et al. An observational study of shift length, crew familiarity, and occupational injury and illness in emergency medical services workers. Occup Environ Med Nov 2015;72(11):798-804.

Reviewed by Catherine Counts, MHA (@CatherineCounts)

Background& Objectives: EMS is high-risk work where extended shifts and lack of familiarity between teammates is common.

Extended shifts: While OSHA defines a normal work shift as 8 hours a day, 5 days a week with at least 8 hours of rest between shift, EMS providers often work an extended shift which may increase the risk of “adverse events, medical errors and attentional deficits.”

Crew Familiarity: Data from the airline industry has shown that a lack of familiarity between pilots is linked to more errors. The average EMS provider will have 19 different partners annually; some will have as many as 50 in a year and thus lack of familiarity may lead to more errors amongst EMS providers.

Given the high rate of extended shifts in EMS, as well as lack of consistency between EMS partners, the objective of this study was to “examine the relationship between shift length and occupational injury while controlling for relevant shift work and teamwork factors.”

Methods: This was a retrospective study using administrative data from 14 EMS agencies with 37 base sites. Agencies provided historical shift schedules and OSHA reports which were matched by date. The primary outcome of interest was OSHA-reported illness or injury, defined as an injury that required medical treatment beyond basic first aid “or [resulted] in loss of consciousness or an inability to perform normal duties without restriction.” The exposure of interest was shift length; the main analysis stratified continuous shift length variable into sections: less than 8 hours, 8-12 hours, 12-16 hours, 16-24 hours, and 24+ hours. Secondary analysis included shift length as a dichotomous variable (yes/no 12+ hours, yes/no 10+ hours), as well as a continuous variable.

The authors also evaluated the effects of the following independent variables of interest:

· Partner Familiarity - Assigned via number of shifts with partner within past 8 weeks, categorized by quartiles.

· Recovery period – time between end of prior shift and start of shift with injury, treated as continuous variable with 1 hour increments

· Consecutive shift - if less than 2-hour break between shifts

· Overnight shift – Yes/No

· Part time – Work less than 34 hours a week

· Number of workers at agency – estimated using unique number of workers during middle four weeks of study period (workforce size is associated with injury reporting)

Results were analyzed using multi-variable mixed-effects logistic models using both fixed and random effects.

Key Results: Fourteen agencies at 37 sites participated over 1 to 3 year period. OSHA reports were matched on date, location and employee. Shifts were excluded when the assigned job role described a non-clinical task. After removing non-clinical and incomplete shift records, the authors included 966, 082 total work shifts from 4,382 employees in their analysis.

Shifts < 8 hours as well as overnight shifts are associated with fewer injuries [relative risk 0.70, 95% CI 051-0.96, p = 0.029 for < 8 hr; RR 0.78, 95% CI 0.65-0.93, p = 0.005 for overnights. 16-24 hour shifts are associated with more injuries when compared with the reference category of 8-12 hour shifts (RR 1.6, 95% CI 1.22-2.10, p=0.001). Familiarity, agency workforce size, part-time status and hours of recovery were not associated with occupational injury or illness. Consecutive shifts also did not significantly alter the risk of occupational injury or illness. Shifts > 24 hours had nearly a three-fold increase in risk (RR 2.88, 95% CI 1.74 – 4.77, p < 0.001), while shifts over 12 hours had a 38% increase in risk of injury (RR 1.38, 95% CI 1.12-1.70, p = 0.002).

Take Home: There is not a one-size-fits-all model for EMS scheduling, but this study further builds on literature that shift length serves as a contributing factor for employee wellbeing. Before any organizational changes are made “trials of novel, minimally intrusive, intra-shift and inter-shift safety management interventions in the EMS setting are needed.”

3. Berkhemer OA et al; MR CLEAN Investigators. A randomized trial of intraarterial treatment for acute ischemic stroke. N Engl J Med Jan 2015;372(1):11-20.

Reviewed by Maia Dorsett, MD PhD, @maiadorsett

Background & Objectives: Intravenous alteplase (tPA) therapy has a narrow therapeutic window and a large number of contraindications. Moreover, it is less effective at opening proximal occlusions of the major intracranial arteries which account for a third of anterior circulation strokes. Initial trials of endovascular approaches to reperfusion were largely negative, but there were a number of concerns about these trials including lack of imaging to confirm proximal vascular occlusion prior to intervention, long time interval to intervention, and use of earlier versions of mechanical thrombectomy devices.

Given the concerns regarding these early trials, the objective of the MR CLEAN trial was to determine whether “intraarterial treatment plus usual care would be more effective than usual care alone in patients with a proximal arterial occlusion in the anterior cerebral circulation that could be treated intra-arterially within 6 hrs of symptom onset.”

Methods: MR CLEAN was a multi-center randomized clinical trial carried out in the Netherlands. Patients were randomized to treatment-group assignments, underwent open-label treatment, and blinded end-point evaluation.

Inclusion criteria included:

1. > 18 years of age with acute ischemic stroke

2. intracranial occlusion of the distal intracranial carotid artery, middle cerebral artery (M1 or M2), or anterior cerebral artery (A1 or A1) confirmed on CT or MR angiography

3. NIHSS > 2

The treatment consisted of intra-arterial treatment of the occlusion. The method of reperfusion (thrombolytic agent, mechanical thrombectomy, or both) was left to the discretion of the interventionalist. If eligible, patients were treated with alteplase or urokinase prior to intervention.

The primary study outcome was modified Rankin scale at 90 days. Secondary outcomes included NIHSS at 24 hrs and at 5 to 7 days post discharge, acivities of daily living as measured by the Barthel index, and health related quality of life as measured by the EuroQol Group 5 Dimension Self-Report Questionnaire at 90 days.

Key Results: The study included 500 participants, 233 (46.6%) were assigned to the intervention group and 267 patients (53.4%) were assigned to the control group. The large majority of patients received IV alteplase prior to intra-arterial intervention (87.1% in intervention group and 90.6% in control group), with a median time to initiation of 85-87 min. 196 of 233 participants in the treatment group received intra-arterial therapy.

For the primary outcome of modified Rankin score, there was a shift in favor of the intervention with an adjusted common odds ratio of 1.67 (95% CI 1.21-2.30). Patients who received intra-arterial treatment were more likely to be functionally independent (modified Ranken score 0 to 2; AOR 2.16; 95% CI, 1.39-3.38) with an absolute increase of 13.5% (32.6% vs. 19.1%, NNT 7.4). Patients receiving intra-arterial treatment also scored higher on the Barthel index (AOR for score 19 or 20 at 90 days 2.1, 95% CI 1.4 – 3.2). There was no significant difference in QQ-5D score (69% vs. 66%).

There was no significant difference in severe adverse events between the two groups during the 90 day follow-up period. Procedure-related complications included embolization into new vascular territories downstream of the occluded vessel (8.6% of patients) with evidence of new ischemic stroke in a different vascular territory in 5.6% patients in the intervention group.

Take Home: There is a functional benefit of intra-arterial therapy for patients with acute ischemic stroke with NIHSS > 2 and confirmed proximal intra-arterial occlusion in the anterior circulation who are able to receive treatment within 6 hrs.

4. Drennan IR, Lin S, Sidalak DE, Morrison LJ. Survival rates in out-of-hospital cardiac arrest patients transported without prehospital return of spontaneous circulation: an observational cohort study. Resuscitation. 2014;85(11):1488-93.

Reviewed by Jeremiah Escajeda, MD, @ JerEscajeda

Background & Objectives: Cardiac arrest is a prevalent disease entity encountered in EMS systems. In 2009, Morrison et al. derived and validated the prehospital Universal Termination of Resuscitation (TOR) Guideline to help direct appropriate termination efforts for both basic life support (BLS) and advanced life support (ALS) prehospital services. To satisfy the TOR Guideline, a cardiac arrest patient must have an 1) unwitnessed arrest by EMS personnel 2) no shock delivered and 3) no return of spontaneous circulation (ROSC) [1]. Implementation of the TOR has been inconsistent and some prehospital services use sole criteria for termination of resuscitation based on no ROSC achieved. The authors sought to report the survival rates of patients without prehospital ROSC who still met transportation criteria based on the TOR Guideline, such as those still who have had either witnessed arrest by EMS personnel or prehospital shock delivered.

Methods: This was a retrospective observational study of the Toronto site Resuscitation Outcomes Consortium (ROC) database from April 1, 2007 –March 31, 2013. Subjects included for analysis were adult patients (≥18 years of age) with cardiac arrest suspected to be cardiac etiology (no trauma, drowning, overdose or asphyxia). EMS services included both BLS (supraglottic device capable) and ALS services. Both EMS and inhospital records were reviewed. 20,207 patients met inclusion criteria.

Key results: Of the 20,207 adult cardiac arrest patients included, 3,374 (16.4%) did not have prehospital ROSC but met the Universal TOR guideline for continued resuscitation and transport. Of these, 551 (16.3%) obtained ROSC in the ED and 122 (3.6%) survived to hospital discharge.

In adjusted multivariable logistical regression, survival to discharge was associated with younger age (OR 0.98; 95% CI 0.97-0.99), initial shockable VF/VT (OR 5.07; 95% CI 2.77-9.30), EMS witnessed arrests (OR 3.51; 95% CI 1.73-7.15), bystander-witnessed arrests (OR 2.11; 95% CI 1.18-3.77) and public locations (OR 1.57; 95% CI 1.02-2.40).

Take home: In this study, using absence of prehospital ROSC as sole determinant for TOR misses an unacceptably high number of potential survivors (3.6%). This is well above the 1% defined threshold for medical futility. Also, the optimal minimum time to obtain prehospital ROSC has not been established. Adherence to all of the Universal TOR criteria results in more accurate prehospital identification of futility in cardiac arrest patients.

1. Morrison LJ, Verbeek PR, Zhan C, Kiss A, Allan KS. Validation of a universal prehospital termination of resuscitation clinical prediction rule for advanced and basic life support providers. Resuscitation. 2009;80(3):324-8.

5. Nichol G et al.; ROC Investigators. Trial of continuous or interrupted chest compressions during CPR. N Engl J Med Dec 2015;373(23):2203-14.

Reviewed by Tom Grawey, DO @EMtgDO

Background & Objectives: Standard CPR consists of manual chest compressions with positive-pressure ventilation until ROSC is obtained. Traditionally chest compressions are interrupted by ventilation, though interruptions reduce circulation of blood and potentially reduce the effectiveness of CPR. One way to reduce time off the chest in CPR is to provide breaths to the patient while continuing CPR. The objective of this study was to determine the effect of continuous chest compressions at a rate of 100 per minute with ventilation provided concurrently at a rate of 10 per minute (experimental group) compared to interrupted compressions with a 30:2 compression:breath ratio (control group) during CPR on the rate of survival, neurologic function, or the rate of adverse events.

Methods: This was a cluster-randomized trial with crossover; 114 EMS agencies across 8 sites were grouped into 47 clusters were randomly assigned to performed continuous or interrupted compressions to all cardiac arrests to which they responded. Twice yearly the cluster was switched to the other resuscitation strategy. Both protocols were followed for a total of 6 minutes, at which point an advanced airway was placed and all patients underwent continuous compressions with breaths provided at a rate of 10 per minute. CPR quality was measured in both groups. The primary outcome was survival to hospital discharge with secondary outcomes including neurologic function at discharge (using modified rankin scale based on the clinical record), adverse events and hospital-free survival (number of days alive and permanently out of the hospital during the first 30 days after the arrest).

Key Results: 1129 of 12,613 patients (9%) in the continuous compressions group and 1072 of 11035 (9.7%) in the 30:2 group survived to hospital discharge. In patients with available data on neurologic status, 883 of 12,560 patients (7%) in the intervention group and 844 of 10,955 (7.7%) in the control group survived with a modified Rankin scale score of 3 or less. Hospital-free survival was significantly shorter in the intervention group than in the control group (mean difference, -0.2 days; 95% CI, -0.3 to -0.1; P=0.004) however this is arguably not clinically significant.

Take home: The study authors conclude that among patients with out of hospital cardiac arrest, continuous chest compressions did not result in significantly higher rates of survival or favorable neurologic status when compared to a 30:2 compression to ventilation ratio. Despite the differences in CPR protocol, the mean difference in chest compression fraction (defined as the proportion of each minute during which compressions were given) between the intervention and control groups was small (0.83±0.14 and 0.77±0.14 ; p<0.001 respectively) in this study which may be contributing to similar outcomes and may emphasize the importance of minimizing compression interruptions. It is unclear whether ventilation quality and strategy contributed to patient outcomes as it was not measured.

6. Fisher R, et al. Police officers can safely and effectively administer intranasal naloxone. Prehosp Emerg Care 2016;20(6):675-80.

Reviewed by Aurora Lybeck, MD, @AuroraLybeck

Background & Objectives: Law enforcement officers (LEOs) are increasingly utilizing naloxone administration for suspected opioid overdose patients prior to EMS arrival, though limited literature is available on the safety and efficacy of such programs. This publication provides an example of training and implementation of LEO administered naloxone program, and aimed to describe indication, response, and disposition of the patients to whom LEO naloxone was administered.

Methods: This is a retrospective case series describing LEO administered naloxone within a large urban police department and included 126 occurrences over 18 months of data collection. They described a 30-minute training program for all LEOs and academy trainees. Instruction topics included signs and symptoms of suspected opioid overdose, naloxone and atomizer devices with hands-on training and instruction to administer 2mg IN naloxone, and required patient transport to the hospital if LEO naloxone was administered. The data was gathered through standard police run reports and an additional naloxone administration data form, using the narrative to complete data when possible. Data elements included:

1) number of times naloxone was administered by police

2) indications for naloxone administration

3) basic patient demographics

4) patient response to naloxone

Other data elements collected included time to EMS arrival on scene and whether the patient was voluntarily or involuntarily transported to the hospital. If patient refused transport, LEO placed patient on involuntary hold and transported them to hospital.

Key Results: The most common indication for LEO administered naloxone was “unconscious/unresponsive” (n=117, 92.9%). Most patients receiving LEO naloxone were white (92.9%), male (59.5%), with average age of 32.8 years. After LEO administration of naloxone, most patients regained consciousness (n=82, 65.1%) or regained spontaneous respirations (n=71, 56.3%), though some demonstrated no response (n=22, 17.5%). Of those with no response to a single dose of LEO administered naloxone, 18 of the 22 outcomes were reported: 3 were fatalities, 3 were non-opioid overdoses, and 12 responded to an additional dose of naloxone by EMS. EMS arrived within 5 minutes in 90% of the calls. 96.8% were transported to the hospital voluntarily. One patient became agitated but later went voluntarily to the hospital. No significant adverse effects noted.

Limitations of the study included selection based only on LEO naloxone administration, potentially missing those opioid overdoses cases not recognized by the LEO, 28 reports with missing EMS follow-up data, lack of toxicological confirmation tests confirming opioid as primarily intoxicant.

Take Home: Trained law enforcement officers can correctly identify an opioid overdose and effectively administer naloxone without significant adverse effects. Further research is needed regarding outcomes and system impact.

7. Rostykus P et al. Variability in the treatment of prehospital hypoglycemia: a structured review of EMS protocols in the United States. Prehosp Emerg Care 2016;20(4):524-30.

By Hawnwan P. Moy, MD, @PECpodcast

Background & Objectives: Hypoglycemia is a frequent emergency situation in many prehospital systems. The traditional approach has been to treat hypoglycemia intravascularly (IV) with fifty milliliters of a 50% solution of glucose containing 25 grams of glucose (commonly known as an amp of D50). However, this treatment is not without risk. D50 is known to over-treat hypoglycemics to inappropriate hyperglycemic levels. Mathematically speaking an amp of D50 is 5 times the amount of glucose in a normal adult and a common pediatric dose of 0.5-1 g/kg (at more dilute concentrations of D25, D12.5, or D10) of glucose provides 6-11 times the normal amount of glucose in a normal child’s blood. Excessive glucose can cause complications in the brittle diabetic and has been known to have detrimental effects in medical conditions such as acute stroke and post cardiac arrest patients. The hypertonic nature of D50 may also cause tissue necrosis should extravasation occur. Finally, dilution and adjustment for the hypoglycemic pediatric population is highly prone to error.

In response to a national drug shortage of D50 and potential harmful side effects, many EMS systems adjusted their treatment of hypoglycemia to now include a 10% dextrose containing solution (D10) instead of D50. Initial studies on D10 indicate that there is a similar time to reversal of hypoglycemia, less post treatment hyperglycemia, and less risk of tissue necrosis given the lower hypertonicity of D10 compared to D50. As a result, this objective of this study was to determine how many EMS systems utilize D10 in their treatment protocols in place of D50. Secondary outcomes were to describe initial and subsequent dextrose treatments, routes of administration, availability of glucagon to treat hypoglycemia, recommendation for post treatment monitoring, and non-transport policies for treated patients.

Methods: The authors performed a structured review of EMS protocols from 50 of the largest populated cities in the United States as well as EMS protocols from http://www.emsprotocols.org. The following data points were manually abstracted by trained investigators: the concentration of glucose recommended for the parenteral reversal of hypoglycemia in adult and pediatric patients, clinical treatment thresholds, dose recommendations, follow-up care, glucagon use, and non- transport policies.

Key Results: The authors collected a total of 185 protocols. From those protocols, 70% had D50 as the only treatment for hypoglycemia, 8% mandated D10 as the only treatment, and 22% allowed either D50 or D10. For the pediatric population, two thirds of the EMS protocols called for 0.5 g/kg of hypertonic glucose with the rest varying between 1 g/kg to less than 0.5 g/kg. The most common initial dose for neonates was 0.5 g/kg. Additionally, IV and intraosseous (IO) routes of administration were allowed in two-thirds of protocols, and a third allowed only IV. Other major differences included post treatment guidelines (only a third of protocols had this) and less than half of all protocols had a non-transport policy of patients with corrected glycemic status.

Take Home: Despite the fact that the administration of D50 has the known side effects of supratherapeutic blood sugar, a majority of EMS systems still utilize D50 for treatment of hypoglycemia. Additionally, this manuscript demonstrates a wide variability in treatment of hypoglycemia in not only the dosage of medication used, but also blood glucose indication for treatment, subsequent dosage of glucose treatment, potential routes, post treatment monitoring, and non-transport policies for treated patients. In many industries, reducing variabilities in protocols reduces errors. Although no two EMS systems are alike, if there is no physiologic or scientific basis for protocol differences, treatment standardization may result in fewer errors and enhance patient safety.

8. Prekker ME et al. Pediatric Intubation by paramedics in a large emergency medical services system: process, challenges, and outcomes. Ann Emerg Med Jan 2016;67(1):20-9.

Reviewed by Maia Dorsett, MD PhD, @maiadorsett

Background & Objectives: In many EMS systems, pediatric intubation is considered a core paramedic skill. However, proficiency in pediatric intubation is hampered by inadequate training, infrequent opportunities to perform the skill, as well as anatomic and equipment differences. The largest clinical trial of pediatric intubation by paramedics found that pediatric intubation and bag-mask-ventilation had comparable survival and neurologic outcomes while intubation delayed transport to the hospital [1]. Evaluating the process used by paramedics in systems in which pediatric intubation is performed is a starting point for quality improvement.

The study had two objectives:

1. Estimate “the incidence of out-of-hospital pediatric intubation within the study community and the EMS system”.

2. Describe “the process used by paramedics in their attempt to intubate these children, with focus on the specific challenges to successful intubation, the corrective actions taken after a failed intubation attempt, and potential procedural complications.”

Methods: The study is a retrospective cohort study of patients < 13 years old who underwent at least one intubation attempt treated by the EMS system serving King County, WA between September 2006 and December 2012. Paramedics in the King County system receive standardize training in airway management and perform an average of 6 pediatric and 40 adult intubations prior to graduation from paramedic school They are also required to perform 12 successful intubations per year.

Data collection involved retrospective chart review of EMS, ED and hospital reports as well as review of a mandated detailed airway report that paramedics must complete for each attempted intubation.

Key Results: In 651,194 calls over 6.3 years, only 299 encounters included an attempted pediatric intubation (0.05% of all calls). Among the 123 paramedics who had at least one pediatric intubation attempt, on average paramedics had no more than one pediatric intubation every 2.6 years. Cardiac arrest was the most common reason(44%) and most commonly involved infants. Preschool and school age children were most commonly intubated for neurologic emergencies, including seizures and trauma.

Amongst all intubation attempts, first pass success was only 66%. First pass success was lower in infants (53%) and children in cardiac arrest (53%). Second attempt success rate was 69% (cumulative success after two attempts was 89%), 57% on 3rd attempt (cumulative success 95%) and 64% after > 4 attempts (cumulative success 97%). The most commonly noted challenge to successful intubation was body fluids (33%). Paramedics changed their approach after failed intubation by suctioning the airway (32%), repositioning the patient (27%), or changing the operator or using a bougie after a failed third attempt. Among the 8 patients who were not successfully intubated out-of-hospital, 5 were intubated in the ED, 1 died prior to arrival and 2 did not end up requiring intubation. Of note, 9% of pediatric patients who were intubated out-of-hospital were extubated in the ED and 1% were discharged home.

The most frequent complication was right mainstem intubation (19%). Major complications (peri-intubation arrest, ET tube dislodgement, injury to the respiratory tract, or bradycardia) occurred in 11% of cases. There were no un-recognized esophageal intubations documented, but endotracheal tube placement could not be retrospectively determined in 50 cases in which the resuscitation was terminated in the field.

Take Home: Pediatric intubation is rarely performed. Even in a system where it is considered a core skill, repeated attempts at intubation were required in a third of patients, although 97% were successfully intubated eventually. Evaluating the process and complications step by step will help determine whether out-of-hospital pediatric intubation is appropriate for an EMS system and opportunities for improvement.

1. Gausche, M., Lewis, R. J., Stratton, S. J., Haynes, B. E., Gunter, C. S., Goodrich, S. M., ... & Seidel, J. S. (2000). Effect of out-of-hospital pediatric endotracheal intubation on survival and neurological outcome: a controlled clinical trial. Jama, 283(6), 783-790.

9. Schlapbach LJ et al. High-flow nasal cannula (HFNC) support in interhospital transport of critically ill children Intensive Care Med Apr 2014;40(4):592-9.

Reviewed by Maia Dorsett, MD PhD, @maiadorsett

Background & Objectives: Escalating respiratory support during transport is inherently difficult; interhospital transport teams have therefore historically had a low threshold for intubating patients prior to transport. However, intubation and invasive ventilation are not without risk. In Pediatric Intensive care, high-flow nasal cannula (HFNC) therapy is increasingly used for respiratory support in critically ill infants and has reduced the need for intubation. The use of HFNC during interhospital transport had not yet been studied. The objective of this study was to evaluate the safety of HFNC during interhospital transfer of critically ill children < 2 years of age and determine the impact of its use on intubation rate and successive PICU management.

Methods: This was a single center, retrospective, pre-post study of critically ill children under 2 years of age requiring interhospital transport by a specialized tertiary pediatric retrieval team and consecutively admitted to the PICU of Mater Children’s Hospital in Brisbane, Australia between 1/2005 and 12/2012. The authors compared the use of respiratory support modes [low flow oxygen/room air, HFNC, NIV (CPAP/BiPAP), or invasive ventilation] and complication rates [need for intubation, pneumothorax, cardiac arrest, need for invasive ventilation in the first 24 hrs of PICU admission] during the 48 month period before and after HFNC was made available as a standard treatment for interhospital transport.

Key Results: 331 children were transported in the pre-HFNC and 462 in the post-HFNC period, with a mean duration of transport of 1.4 hours. After introduction of HFNC, 33% of all patients were transported on HFNC. Intubation rates decreased between the pre (49%) and post(35%) periods. This was in part due to decrease rate of intubation by the referring hospital (36% pre/28% post), but fewer patients were intubated by the retrieval team as well (13% pre/7% post).

In the subgroup of patients with bronchiolitis, there was a significant decrease in the proportion of patients with invasive ventilation initiated by the retrieval team (33% vs. 15%, p = 0.001). Among patients receiving HFNC, bronchiolitis was the most common condition requiring transport (77%).

There was no increase in adverse events post introduction of HFNC, including no cases of patients requiring intubation during transport. There was no significant difference between need for intubation during the first 24 hrs of PICU admission in the pre/post period.

Take Home: HFNC therapy during transport of critically ill infants appears to be safe and may have the potential to reduce need for intubation and invasive ventilation.

10. Clemency BM, Bart JA, Malhotra A, Klun T, Campanella V, Lindstrom H. Patients immobilized with a long spine board rarely have unstable thoracolumbar injuries. Prehosp Emerg Care 2016;20(2):266-72.

Reviewed by Brandon Bleess, MD @BBBleess

Background & Objectives: Because of concern that patients with unstable spine injuries are at risk for secondary mechanical injury if exposed to significant movement, long spine boards and cervical collars were widely adopted as a mainstay of treatment for patients with suspected spine injury. However, multiple studies have demonstrated potential harms of spine board use, including respiratory compromise, pain, tissue ischemia, and unnecessary imaging. In order to objectively compare the relative risk and benefit of spinal immobilization, the objective of this research was to “determine the prevalence of unstable thoracolumbar spine injuries among patients receiving prehospital spine immobilization.”

Methods: This was a retrospective study of prehospital and hospital records of patients cared for by a single, large, private EMS agency in Western New York from January 1, 2010 through December 31, 2013. The corresponding hospital data was obtained from a single, Urban, academic Level I Trauma Center that served an 8 county region with approximately 65,000 emergency department visits per year. During the study, EMS operated under a single statewide “Suspected Spinal Injury” protocol requiring complete spinal immobilization when spinal injury was suspected. Inclusion criteria included age > 18 years old, documented spinal immobilization from the scene, and transport to the study hospital.

Hospital records were reviewed for mechanism of injury, imaging of the thoracolumbar spine, and presence of any acute fractures, dislocations, or subluxations. For patients with injuries identified on spinal imaging, performance of thoracolumbar spine surgery during hospitalization was used as a marker for unstable thoracolumbar spine injury. The primary outcome was the percentage of patients with unstable thoracolumbar injury who underwent prehospital spine immobilization following blunt trauma. Rate of imaging and injuries by mechanism were secondary outcomes.

Key Results: Immobilization was documented on 5,593 patients transported to the ED. 97% of prehospital records were successfully linked with the corresponding hospital record. Spinal imaging was ordered in 82.5% of subjects and thoracolumbar imaging specifically was ordered in 51.3%of subjects. An acute thoracolumbar fracture, dislocation, or subluxation was present in 4.3% of cases. An unstable injury was present in 0.5% cases (n=29). No unstable injuries were found among the 951 patients that were immobilized following ground level falls. Falls from heights greater than 20 feet had the greatest chance of causing any fractures and unstable injuries with 10% (8/80) having unstable fractures.

Take home: While spinal imaging is commonly performed on blunt trauma patients who undergo prehospital spinal immobilization, unstable thoracolumbar injury is a rare occurrence.

11. Newgard CD et al.; Western Emergency Services Translational Research Network (WESTRN) Investigators. Improving early identification of the high-risk elderly trauma patient by emergency medical services. Injury Jan 2016;47(1):19-25.

Reviewed by Melody Glenn, MD, @MGlennEM

Background & Objectives: Existing field triage guidelines often fail to identify serious injuries in elderly trauma patients. This is partially due to the increased likelihood of sustaining injury from low-velocity mechanisms (e.g. ground-level falls) and their different physiologic responses to injury amongst the elderly. Under-triage leads to a greater proportion of seriously injured elders being transported to non-trauma hospitals, where their needs may outstretch hospital capabilities. Although the CDC added a “special consideration” section relating to adults >55 into their 2011 field triage guidelines for injured patients, little evidence exists that similar EMS protocol changes have decreased under-triage.

The objectives of the study were to:

Define the high-risk injured older adult using prognostic differences associated with different injury patterns
Derive alternative field trauma triage guidelines that mesh with current national guidelines to improve identification of high-risk elderly trauma patients.

Methods: This was a retrospective cohort study of 33,298 injured adults 65 years or older who were transported by 94 EMS agencies to 122 hospitals in 7 western regions in the United States from 2006 - 2008. Only patients with matched hospital records were included. The researchers used Abbreviated Injury Scale (AIS) scores or need for surgery to create 5 definitions/categories of “serious injury,” including: Injury Severity Score (ISS) ≥ 16, serious traumatic brain injury (TBI), serious chest injury, serious chest injury, serious abdomen-pelvic injury, and serious extremity injury. They considered in-hospital mortality as a marker of prognosis to compare definitions.

They derived an alternative set of field triage guidelines to identify high-risk older adults, using 60% of the sample to derive and cross-validate their decision tree. The remaining 40% were used to validate the tree.

Key Results: 80% of the elders in their sample of 32,298 patients were injured by falls. Out of their cohort, 13,401 met their definition for serious traumatic injury (4.5% with ISS ≥ 16, 4.7% with TBI, 3.4% w serious chest injury, 1.7% with Abdomen-Pelvis injury, and 3.1% with in-hospital mortality). Patients with isolated serious extremity injuries had the lowest mortality.

Based on having any positive triage criterion from the 23 field trauma triage criteria currently in existence at the study sites, 3,299 serious trauma patients would have been identified, resulting in a sensitivity of 75.9% (95% CI 72.3-79.2%) and a specificity of 77.8% (95% CI 77.1-78.5%).

Their alternative triage guidelines included: any positive triage criterion from the current guidelines, GCS ≤ 14, and abnormal vital signs. Adding these triage criteria resulted in identifying an additional 4,744 patients with serious traumatic injuries, yielding a higher sensitivity of 92.1% (95% CI 89.6-94.1%) and a lower specificity of 41.5% (95% CI 40.6-42.4%).

Take Home: Elderly-specific triage guidelines can be applied to the current national triage guidelines, and will result in greater identification of those with serious traumatic injuries. However, such changes would also result in over-triage.

Further studies should evaluate additional variables/assessment tools that could be used to increase sensitivity without decreasing specificity, the cost and resource implications of adopting new, less-specific triage guidelines, and whether or not there is a survival benefit associated with the treatment of elderly trauma patients at major trauma centers.

**12. Scerbo MH, Mumm JP, Gates K, Love JD, Wade CE, Holcomb JB, Cotton BA. Safety and Appropriateness of Tourniquets in 105 Civilians. Prehosp Emerg Care. 2016 Nov-Dec;20(6):712-722.**

Reviewed by Scott Goldberg, MD MPH, @EMS_Boston

Background & Objectives: Tourniquets have been commonly used in the military environment for some time. However, tourniquet use in the civilian setting is still controversial and wide variations exist in recommendations for tourniquet use in the civilian population. The objective of this study was to examine tourniquet application in the civilian setting as well as evaluate the safety and efficacy of application by prehospital and emergency department (ED) providers.

Methods: This was a single center retrospective cohort study including all trauma activations from October 2008 through May 2013 in which a tourniquet was applied in the field or in the ED. All tourniquets used in this system were Combat Application Tourniquets (CAT). The authors defined tourniquet use as absolutely indicated if it met any of the following criteria: urgent or operative intervention for limb injury within 2 hrs of arrival or a vascular injury requiring repair or ligation. Tourniquet use was considered relatively indicated if there was documentation of significant blood loss at the scene or a major musculoskeletal/soft tissue injury requiring a non-emergent or urgent operation (between 2 and 8 hours of hospital arrival).

Key Results: Over the study period there were 105 tourniquet applications included for analysis, of which 14 were placed in the ED with the remainder placed in the field. Nine patients had a tourniquet placed in the field and an additional tourniquet placed after arrival to the ED. Approximately an equal number of tourniquets were placed for penetrating and blunt trauma.

Ninety percent of tourniquet placements met the apriori definition of indicated for placement. All of the 10 non-indicated tourniquets were placed in the field. However, it is important to differentiate not indicated from inappropriate. All of the tourniquet applications in this cohort were placed with the intent to control major hemorrhage, and while on final determination of the patient’s injury the tourniquet may have been deemed not indicated, its use was nevertheless felt to be appropriate by the field provider.

There were no significant differences in patient ages, transport times, injury severity scores, or vital signs between indicated and non-indicated tourniquet placement. Thirty percent of patients underwent limb amputation, none of which were related to tourniquet use. Eighteen percent of patients had a complication potentially related to tourniquet use, including amputation, renal failure, compartment syndrome, nerve palsy, or venous thromboembolism. However, after review of each of these cases, none of the complications were felt to be related to use of the tourniquet, with the majority of complications resulting from the injury itself.

Take Home: Tourniquet application was safe and effective in this civilian patient population. The complications seen in the cohort were related to the injuries sustained and not attributable to tourniquet use. Tourniquets should therefore be considered as a potentially life-saving measure for patients suffering from hemorrhage from blunt and penetrating trauma.

Prefer a pdf version? Download one here.

California’s Quest for Evidence-Based EMS Protocols: Chest Pain

Book Club Sessions: Evicted, Poverty and Profit in the American City

by Melody Glenn, MD

Perhaps the success of Harvard sociologist Matthew Desmond’s Evicted, Poverty and Profit in the American City, lies in its engaging style, reading more like a page-turning novel and less like an academic analysis. Through following the ups and downs of its colorful characters, we realize the profound impact that stable housing has on individuals, communities, and their health. Although the setting is in Milwaukee, the lessons are transferable, as unaffordable housing is a problem nationwide.

From the individuals’ narratives, we see how easy it is to crash to the bottom if you are poor; there is no safety net to catch you. In the first pages of the book, Arleen and her two boys are evicted after a man breaks down their door. There is little incentive for landlords in poor neighborhoods to pay for costly repairs, as they know that the market for low-cost housing far outstrips demand. After a family has an eviction on their record, they have even less bargaining power, and are thus more likely to be forced into substandard housing conditions, as are Arleen and her boys when they subsequently rent a decrepit $550/month apartment in one of the worst neighborhoods in American’s fourth-poorest city. The rent takes 88% of Arleen’s monthly income, which is not uncommon. The majority of poor renting families spend half of their income on housing, which is far above the traditionally recommended 30%. Given those numbers, perhaps it isn’t so surprising that 1 in 8 renters experienced a forced move between 2009 and 2011 in Milwaukee, and that similar numbers are seen nationwide.

Image Source: Desmond, M.  Unaffordable America: Poverty, housing, and eviction. Fast Focus, University of Wisconsin-Madison. 2015; 22. http://www.irp.wisc.edu/publications/fastfocus/pdfs/FF22-2015.pdf — Image Source: Desmond, M. Unaffordable America: Poverty, housing, and eviction. Fast Focus, University of Wisconsin-Madison. 2015; 22. http://www.irp.wisc.edu/publications/fastfocus/pdfs/FF22-2015.pdf

Arleen and her boys are again evicted, and Arleen attempts, unsuccessfully, to fight her eviction at eviction court. As people have no right to an attorney in civil court, 90% of tenants in housing courts nationwide do not have attorneys, whereas 90% of landlords do [1]. Looking around her, Arleen notices that the other tenants are predominantly black females. Matthew Desmond writes, “If incarceration had come to define the lives of men from impoverished black neighborhoods, eviction was shaping the lives of women. Poor black men were locked up. Poor black women were locked out.” [1]

Later in the book, Arleen and her boys are again evicted, but this time via the nuisance property ordinance. After their roommate calls 911 in response to a domestic disturbance in the unit upstairs, the police contact the landlord, informing her that she will be responsible for a fine or jail time if there are any further “nuisance activities” on her property, and requiring her to submit a plan as to how she will “abate the nuisance activities.” Her initial plan was not accepted by the police department, but the 2nd plan, eviction of the tenants, was.

Nationwide, the majority of nuisance citations are related to domestic violence calls, which discourages victims from calling 911 [1]. A study by Rollins et al suggested that among victims of intimate partner violence, evictions and housing instability were predictors of PTSD, depression, increased work/school absence, and increased ED/hospital use [2]. Additionally, black tenants are more likely to receive nuisance citations, and thus evictions, than are their white counterparts. In black neighborhoods, 1 in 16 eligible properties receive a citation, compared to 1 in 41 in white neighborhoods [1].

Arleen and her boys move into a shelter, and within the span of 2 months, she applies to, and is rejected by, 89 prospective apartments. This is likely secondary to both her eviction record and the fact that she has children. The Fair Housing Act of 1968 did not consider families with children a protected class, so many units charged children-damage deposits and monthly surcharges. In 1988, housing discrimination against children and families was outlawed, but the practice continued. In as many as 7 in 10 housing searches, families with children were turned away [1].

Arleen’s eviction is also a strike against her when applying for public housing assistance. Even if she qualified, ¾ of families in America who qualify for assistance receive nothing. In Milwaukee, the list for rental assistance was frozen [1]. In some cities, the wait for public housing is counted in decades.

Evictions have dramatic, negative effects on people’s jobs and children’s educational trajectories. Arleen’s son Jori attends 5 different schools between the 7th and 8th grades, and her son Jafaris starts to show signs of anger issues and learning disabilities, which is not uncommon in children who are experience housing instability. Multiple studies have shown that evictions and housing instability increase rates of depression, suicide attempts, decreased medication compliance, gaps in health insurance, and even low birth weights [3-9].

James Baldwin (Image Source: Wiki Commons)

Although Arleen is not working, many of the other characters in the book are, or were, until they were evicted. Desmond notes that workers who involuntarily lost their housing were roughly 20 percent more likely subsequently lose their jobs, compared to similar workers who did not [10]. [GM2] As eviction leads to so many destabilizing, downstream effects that place individuals and their communities on a downward trajectory, Desmond argues that eviction is a cause, not just a condition, of poverty. As James Baldwin wrote in Fifth Avenue, Uptown “Anyone who has ever struggled with poverty knows how extremely expensive it is to be poor; and if one is a member of a captive population, economically speaking, one's feet have simply been placed on the treadmill forever." [11]

On April 4th, our interdisciplinary book club met at The Laughing Monk Brewery to discuss the relevance of Desmond’s work to our communities and professional practice here in the Bay Area. In the Mission neighborhood, where many of us work at Zuckerberg San Francisco General Hospital, the Anti-Eviction Mapping Project documents that there have been 908 evictions since 2011 [12]. They also have a map of all evictions in San Francisco, stratified by type, which shows that nuisance evictions are the 3rd most common cause.

The statistics and arguments in Desmond’s book support the theory that of all the social determinants of health, housing insecurity may be one of the most detrimental. For those of you who may be new to the term, “social determinants of health,” the WHO defines them as the forces that lead to health inequities and are beyond the span of control of the individual, and include education, race, neighborhood, and labor and housing markets [13]. According to a study by Galea et al, social factors are attributable to more deaths in the US than are acute MI’s, CVA, and lung cancer [14].

Image source:http://kff.org/disparities-policy/issue-brief/beyond-health-care-the-role-of-social-determinants-in-promoting-health-and-health-equity/ — Image source:
http://kff.org/disparities-policy/issue-brief/beyond-health-care-the-role-of-social-determinants-in-promoting-health-and-health-equity/

In San Francisco, the Department of Public Health began to treat housing instability as a public health issue. They saw that many of their highest users and those who were severely disabled often did not qualify for low-income housing, so they opened their own housing facilities [15]. They obtained federal funds dedicated for initiatives based on Housing First, which is an approach that reduces barriers, such as preconditions of abstinence, to housing, under the belief that addiction and mental health issues will improve after individuals attain a safe living situation. In 2009, JAMA published an article showing that implementation of a Housing First intervention for chronically homeless individuals with severe alcohol problems and high service use lead to a decrease in health care and public service use, saving an average of $2,449 per person after accounting for housing program costs [16].

Even with the involvement of local government, there still isn’t enough low-cost or subsidized housing to meet the demand. As Dr. Barry Zevin, the medical director of the San Francisco Street Medicine & Shelter Health Team, stated, “We are trying to find local solutions to a national problem.” That being said, it does seem like San Francisco faces some additional challenges due to particularly high rents and limited space. According to Trulia, the median price of a one-bedroom apartment in SF was just shy of $3,000 month in October of 2016. According to an article in Quartz, in 2005, the Bay Area added 64,000 in jobs but only 5,000 new homes were built[17. In San Francisco, there are an estimated 6,000- 7,000 homeless people in the city every night, and public health records suggest that a whopping 13,000 – 14,000 people experience homelessness at some point during the year [18]. As Dr. Zevin summarizes, we have a “liberal ethos that crashes up against incredible disparity.”

April Bassett, a captain & community paramedic with the San Francisco Fire Department who focuses on improving care for the city’s frequent 911-users, addressed the myth of the existence of a strong safety net: “Let’s talk about how hard it is to get benefits in the city.” In order to get social services, you need an ID. In order to get an ID mailed to you, you need an address. Furthermore, if you have an untreated psychiatric condition, you may be too disorganized to complete the multi-step process of obtaining an ID. Dr. Zevin, much like April and Desmond, has learned just “how hard the gains are, yet how easy and multiplying the losses are.”

As an emergency physician in the Bay Area, I have come to see how housing instability affects the health of my patients, and the effectiveness (or lack thereof) of my interventions. Diabetics with DKA because their insulin was stolen while living on the street, patients whose blood pressure was sky-high because their medications were left behind in their old house, patients with severe asthma exacerbations because they did not have enough money left over to pay for their inhaler even after working two jobs, patients whose chronic venous stasis ulcers continue to worsen because they don’t have a clean place to wash and change their dressings. My treatments just feel like a Band-Aid that will become ripped off as soon as they leave the ED. I imagine I’ll see them again in a few days, and the data supports this; a study by the Agency for Healthcare Research and Quality found that ED visits are 9-12 times higher among homeless men and women [19].

As medics and emergency medicine practitioners, what can we do? Dr. Zevin stressed the importance of simply documenting our patients’ housing status and if they have evidence of psychosis. It also helps us better meet our patients where they are, and adds perspective and continuity to future encounters (i.e., is the homelessness or mental illness new or is it years old?). Then we can better address “their barriers to care and the system gaps.” Maggie Roberts JD, a civil rights attorney who often advocates for those with disabilities, emphasizes the value of this simple task; if these patients ever try to apply for benefits, such documentation is hugely important.

Amber Quelvog, an ER nurse at San Francisco General Hospital, suggested that the nurse in triage check a box in the chart if a patient were currently homeless, and then the patient’s chart could be forwarded to one of the public health clinics (if such a transfer of information were made more systematic and HIPAA compliant) As Dr. Zevin asserts, “If someone is on [our] radar, there is a better chance that they will get to what they need.”

We also have to decide whether or not we think housing is a human right, and if so, support policies and regulations that increase access to housing. Matthew Desmond suggests making the current voucher system more efficient and expanding its availability to include more people. Josh Seim, a PhD candidate in sociology at UC Berkeley, thinks the solution needs to involve more public housing.

As EMS providers, I believe that this is in our wheelhouse. One direct way that we can work to address the negative health effects of housing instability is through community paramedicine initiatives that better plug people into the care they need -- whether that is social services, primary care, mental health, or addiction programs. In San Francisco, ED providers and field medics refer vulnerable, frequent-user patients to their EMS-6 Community Paramedicine team [20]. April, or one of the other community paramedics, and a social worker then go to the field to meet the patient wherever they are, from a tent on the sidewalk to a hospital bed at UCSF, and start to address their individual barriers to care. Often times, this centers around housing instability, so the team helps their clients fill out the necessary shelter or supportive housing applications, or gets them into medical detox programs that can better help them in this transition. They help their patients better navigate the system. If your EMS system doesn’t have a community paramedicine program, there are other ways to have an effect, such as medic-led patient referrals to social services organizations, or EMS Agency support.

Dr. Zevin tries to end the discussion with an uplifting tone, “The resilience of the people I see is amazing. The things that would kill me do not kill them. The things that would destroy my spirit mostly do not destroy the spirit of my patients. Their material circumstances are horrible, and the outlook is pretty bleak. But people keep trying. And they appreciate even the little things we can do for them. I need to hold onto that, or things look pretty bleak. These are consequences of national problems, not local problems, although there are strange local bits to this. Donate. Understand the victories we have gotten. That helps me keep going.”

Image Source:  Melody Glenn, personal photo — Image Source: Melody Glenn, personal photo

Take home points:

Homelessness and housing instability have negative health outcomes

Homelessness is associated with a higher frequency of ER visits

Document homelessness and abnormalities in your patients’ psychiatric exams

EMS can help refer patients to needed social services and address barriers to care

References

1. Desmond, Matthew. Evicted: Poverty and Profit in the American City. 2016.

2. Rollins C, Glass NE, Perrin NA, Billhardt KA, Clough A, Barnes K, HansonGC, Bloom TL. Housing instability is a strong predictor of poor health outcomes as level of danger in abusive relationship: findings from the SHARE study. J Interpers Violence. 2012 Mar; 27(4): 623-43.

3. Bolívar Muñoz J1, Bernal Solano M2, Mateo Rodríguez I3, Daponte Codina A3, Escudero Espinosa C4, Sánchez Cantalejo C4, González Usera I5, Robles Ortega H5, Mata Martín JL5, Fernández Santaella MC5, Vila Castellar J5. The health of adults undergoing an eviction process]. Gac Sanit. 2016 Jan-Feb;30(1):4-10. [Article in Spanish]

4. Burgard SA1, Seefeldt KS, Zelner S.Housing instability and health: findings from the Michigan Recession and Recovery Study. Soc Sci Med. 2012 Dec;75(12):2215-24.

5. Carrion BV1, Earnshaw VA, Kershaw T, Lewis JB, Stasko EC, Tobin JN, Ickovics JR. Housing instability and birth weight among young urban mothers.J Urban Health. 2015 Feb;92(1):1-9. doi: 10.1007/s11524-014-9913-4.

6. Carroll A1, Corman H2, Curtis MA3, Noonan K4, Reichman NE5. Housing Instability and Children's Health Insurance Gaps. Acad Pediatr. 2017 Feb 20. pii: S1876-2859(17)30062-1.

7. Fowler KA1, Gladden RM, Vagi KJ, Barnes J, Frazier L. Increase in suicides associated with home eviction and foreclosure during the US housing crisis: findings from 16 National Violent Death Reporting System States, 2005-2010. Am J Public Health. 2015 Feb;105(2):311-6.

8. Rojas, Y. Evictions and short-term all-cause mortality: a 3-year follow-up study of a middle-aged Swedish population. Int J Public Health. 2017 Apr;62(3):343-351. 9. Rojas Y1, Stenberg SÅ1. Evictions and suicide: a follow-up study of almost 22,000 Swedish households in the wake of the global financial crisis. J Epidemiol Community Health. 2016 Apr;70(4):409-13.

9. Vásquez-Vera H1, Palència L2, Magna I3, Mena C3, Neira J3, Borrell C4. The threat of home eviction and its effects on health through the equity lens: A systematic review. Soc Sci Med. 2017 Feb;175:199-208.

10. Desmond, M. Unaffordable America: Poverty, housing, and eviction. Fast Focus, University of Wisconsin-Madison. 2015; 22. http://www.irp.wisc.edu/publications/fastfocus/pdfs/FF22-2015.pdf

11. Baldwin, J. Firth Avenue, Uptown. Esquire. July 1960. http://www.esquire.com/news-politics/a3638/fifth-avenue-uptown/

12. http://www.antievictionmap.com/

13. http://www.who.int/social_determinants/en/

14. Galea S et.al. Estimated Deaths Attributable to Social Factors in the US. AJPH:June 16,2011;eprint.

15. per Barry Zevin, MD

16. Larimer, Mary E.; Malone, Daniel K.; Garner, Michelle D.; Atkins, David C.; Burlingham, Bonnie; Lonczak, Heather S.; Tanzer, Kenneth; Ginzler, Joshua; Clifasefi, Seema L.; Hobson, William G.; Marlatt, G. Alan (1 April 2009). "Health Care and Public Service Use and Costs Before and After Provision of Housing for Chronically Homeless Persons with Severe Alcohol Problems". JAMA. 301 (13): 1349–57.

17. https://qz.com/711854/the-inequality-happening-now-in-san-francisco-will-impact-america-for-generations-to-come/>.

18. http://dhsh.sfgov.org/research-reports/san-francisco-homeless-point-in-time-count-reports/

19. Hwang SW, Henderson MJ. Health Care Utilization in Homeless People: Translating Research into Policy and Practice. Agency for Healthcare Research and Quality Working Paper No. 10002, October 2010, http://gold.ahrq.gov.

20. http://www.sfchronicle.com/bayarea/article/Emergency-responder-to-be-honored-for-treating-6828232.php

One size does not fit all: Should we be using mechanical CPR in OHCA?

by Maia Dorsett, MD PhD (@maiadorsett)

Recap of the Case:

A 64 yo male is having dinner with his family when he begins to feel lightheaded and nauseated. As he stands up to leave the table, he collapses to the ground. His family calls 911. As he is unresponsive with agonal respirations, the call is dispatched as a cardiac arrest and the patient's family is instructed to perform CPR via pre-arrival instructions.

On EMS arrival, the patient is found to be pulseless. Compressions are continued while the patient is connected to the monitor. The EMS supervisor arrives on scene shortly after with a newly purchased mechanical CPR device.

Should the mechanical CPR device be used? If so, when should it be applied?

Do you have a protocol dedicated to use of mechanical CPR? If you utilize mechanical CPR, how do you integrate it into your cardiac arrest resuscitation so as to minimize interruption of chest compressions?

Review:

High quality compressions of adequate depth, rate, recoil and with minimal interruption are crucial to neurologically-intact survival from out of hospital cardiac arrest (OHCA). Quality compressions require considerable physical effort on the part of providers leading to decreased compression quality over time. A number of mechanical CPR devices have been developed with the goal of maintaining compression consistency and off-loading the work of compressions [1]. However, when applied to all patients with cardiac arrest, mechanical CPR is equivalent or inferior to manual CPR in achieving neurologically-intact survival.

The first large trial to examine the effect of mechanical CPR on cardiac arrest outcomes was a multicenter randomized control trial in the United States and Canada [2]. The trial enrolled patients from 2004 to 2005. Individual stations within each site were randomized to manual CPR or mechanical CPR with an AutoPulse band device, with subsequent alternation between intervention and control groups. They found no difference in the primary outcome of 4 hr survival between manual and mechanical CPR (N=1071; 29.5% vs 28.5%; P=.74), but found that an overall lower rate of neurologically-intact survival among those patients who received mechanical CPR (3.1 % for mechanical CPR vs. 7.5% for manual CPR , p=.006). The study was terminated early because of poorer neurologic outcomes in the mechanical CPR group.

Following this, three randomized control trials (CIRC, LINC and PARAMEDIC) found that mechanical CPR was non-inferior to manual CPR.

The CIRC trial was a randomized control trial of mechanical CPR using the Autopulse band device versus standard CPR [3]. It included all 4231 patients with arrests of presumed cardiac origin. Patients were randomized by sealed envelopes opened after manual compressions were initiated. They found no difference in survival to hospital discharge between mechanical and manual CPR (OR for mechanical compared with manual: 1.06, 95% CI 0.83-1.37). For the secondary outcome of good neurologic outcome (defined as a modified Rankin score of < 3 at discharge from the hospital), there was no difference between mechanical and manual CPR (OR for mechanical compared with manual; aOR 0.80, 95% CI 0.47–1.37).

Unlike the CIRC trial, the LINC trial (Lucas IN Cardiac arrest) used the plunger-type Lucas device. 2593 patients were randomized using a sealed envelope after initiation of manual compressions [4]. The mechanical compression arm of the study varied more than just the mode of CPR. In the Lucas arm, the first defibrillation shock was delivered during ongoing compressions without pausing to check the heart rhythm and CPR cycles were extended to 3 minutes between subsequent rhythm checks. When comparing the two arms, the authors found no difference between 4 hr survival (307/1300 [23.6%] vs 305/1289 [23.7%]; risk difference, −0.05%; 95% CI, –3.3% to 3.2%; P<.99) and neurologic outcome at hospital discharge (108/1300(8.3 %) vs. 100/1289 (7.8%), risk difference, 0.55; 95% CI−1.5% to 2.6%; p = 0.61). Mechanical and manual CPR groups were similar in the proportion of patients with witnessed arrest, bystander CPR and shockable rhythm.

The PARAMEDIC trial also compared mechanical CPR with a LUCAS device to manual compressions [5]. Randomization was done with a computer-generated randomization sequence that assigned particular vehicles to carry the device. The study enrolled 4471 patients with similar baseline characteristics. Manual compressions were initiated until the device could be placed. During pauses, if a shockable rhythm was found, the LUCAS was turned back on and defibrillation took place with ongoing mechanical CPR. The study found no significant difference in the primary outcome of survival to 30 days (aOR 0.86, 95% CI 0.64-1.15). Survival with favorable neurologic outcome at 3 months was lower in the group receiving mechanical CPR (aOR 0.72, 95% CI 0.52-0.99).

Two subsequent meta-analyses found no difference between manual and mechanical CPR on favorable neurologic outcome [6,7].

In an effort to compare outcomes for patients receiving manual versus mechanical CPR in the “real world” outside of the well-trained and monitored randomized control trials, two recently published studies retrospectively evaluated outcomes from patients in the CARES registry.

First, an observational cohort study of all cardiac arrests treated in the state of Utah from May 2012 through June 2015 tracked via the CARES registry was published in January 2016 [8]. This included adult patients with non-traumatic arrest who were either defibrillated with an AED or received chest compressions from a prehospital provider. They analyzed 2600 resuscitation attempts. Overall, mechanical CPR (predominantly with the AutoPulse device) was used in only 16% of all arrests. Patients who received mechanical CPR also were more likely to have several poor prognostic factors; their arrests were less likely to be witnessed, more likely to present with asystole and require more interventions (ACLS medications, advanced airway placement). The authors therefore used a regression model with weighted propensity to scores in order to control for possible confounders/selection bias – witnessed arrest, bystander CPR, deliver of bystander AED shock, initial shockable rhythm. Using this approach, the authors found that the adjusted relative risk for neurologically-intact survival with mechanical CPR compared to manual CPR was 0.41 (95% CI, 0.24 – 0.70, p=0.001). In a subgroup analysis, mechanical CPR was still associated decreased likelihood of neurologically-intact survival in patients with a shockable rhythm on initial check (aRR 0.47, 95% CI 0.25 – 0.86, p=0.001) and EMS-witnessed arrests (RR 0.18, 95% CI 0.08-0.40), p< 0.0001).

More recently, the analysis of the CARES registry and been expanded to a national scale [9]. A retrospective study of CARES registry data from January 2013 to December 2015 included an evaluation of outcomes in 80,861 patients. Using a multivariable regression model to control for arrest characteristics – age, arrest location, bystander CPR, AED use, initial rhythm, witnessed arrest, post-arrest targeted temperature management, successful placement of an advanced airway – they found that patients who received mechanical CPR were less likely to survive to hospital discharge (7.0% vs. 11.3%, p < 0.001) or have neurologically-intact survival (5.6% vs. 9.5%, P < 0.0001).

The above studies not only find lack of benefit, but also potential harm in the employment of mechanical CPR devices. Should this be the end of their use? Not necessarily, but these studies should make us strongly consider why use of mechanical CPR may be associated with worse neurologic outcomes.

Comments in response to the discussion forum questions focused on 3 key issues surrounding employment of mechanical CPR: Training, Personnel and potential need for transport.

Training and Personnel:

“The first thing I would like to know is do all of the crew members have training and knowledge of the device to be used? Does this device come on a fly car such as a physician vehicle or is this something that all units and crew members have practiced beforehand and is available to every transporting unit? Was the device implemented yesterday or 6 months ago? To maximize easy of use and decrease interruption of chest compressions, a comprehensive crowd knowledge and familiarity would be best. “

“Locally, in accordance with our statewide protocols, we limit use of mechanical compression devices during the first 10 minutes of resuscitation (link). With more time into an arrest, this generally also means more time for hands to arrive to assist. Having more crew members to assist, the better. In using the LUCAS device, we have found that having at least four people is ideal." – J. Escajeda

The association of mechanical CPR with worse neurologic outcome may be due to prolonged interruption of compressions when the device is applied. Indeed, the one site with a quality improvement initiative to minimized interruption in compressions in the Hallstrom et. al. trial changed their protocols mid-study as they found that there was a prolonged time without compressions while deploying the mechanical CPR device [2]. This does not mean that sufficient training cannot improve the efficiency and coordination with which the device is placed – but this requires recognition that funding for a mechanical CPR device must be accompanied by funding to provide adequate training in its use and ongoing quality review of effect on local outcomes.

Potential Need for Transport:

“The other question that comes to mind is what are your end-points to this particular arrest? Is this an organized rhythm (along with the mentioned witnessed arrest, bystander CPR). We know that there is no demonstrated benefit to a device [Perkins, Rubertsson], however, a role could be to maximize compressions during transport, a time when maintaining compression quality is difficult. Is this someone that is being transported to the hospital for other interventions such as ECPR?” – J. Escajeda

While staying on scene until ROSC or termination of arrest may be appropriate for the most cardiac arrest cases, there is emerging evidence that some patients with refractory arrest should be considered candidates for advanced therapies including ECMO, percutaneous coronary intervention or pulmonary embolectomy. Recently, initial results of the CHEER trial (mechanical CPR, Hypothermia, ECMO and Early Reperfusion) therapy carried in out Australia were published [10]. This pilot trial of a very select group of patients (age 18-65 years, cardiac arrest due to suspected cardiac etiology, chest compressions within 10 minutes, initial rhythm of ventricular fibrillation, absence of pre-existing non-cardiac morbidities affecting activities of daily living, and general gestalt by a critical care physician that the etiology of cardiac arrest would be reversible if veno-arterial ECMO and definitive treatment could be provided immediately) included 11 patients with OHCA. There were 5 survivors, all of whom were discharged directly home with full neurologic recovery, despite a median collapse to hospital arrival of 48 minutes (IQR 23-64).

As transport is a particularly difficult time to maintain quality compressions, mechanical CPR may be of benefit in the group of patients who are being transported (including post-ROSC patients who are high risk of re-arrest en route to the hospital).

Take Home: In general, mechanical CPR has no proven benefit in cardiac arrest and is associated with lower neurologically-intact survival in some studies. Mechanical CPR may best be utilized in the care of patients requiring transport, and EMS protocols should stress application of the device in a manner that leads to minimal interruption of compressions. For an example protocol, see (this protocol) from Sedgwick County EMS (written by Sabina Braithwaite, modified from Michael Levy’s Anchorage protocol).

Other #FOAMed posts on Mechanical CPR

EM Nerd: The Case of the Bridge to Nowhere

REBEL EM: The Death of Mechanical CPR?

References:

1. Ward, K. R., Menegazzi, J. J., Zelenak, R. R., Sullivan, R. J., & McSwain, N. E. (1993). A comparison of chest compressions between mechanical and manual CPR by monitoring end-tidal PCO2 during human cardiac arrest. Annals of emergency medicine, 22(4), 669-674.

2. Hallstrom, A., Rea, T. D., Sayre, M. R., Christenson, J., Anton, A. R., Mosesso, V. N., ... & Yahn, S. (2006). Manual chest compression vs use of an automated chest compression device during resuscitation following out-of-hospital cardiac arrest: a randomized trial. Jama, 295(22), 2620-2628.

3. Wik, L., Olsen, J. A., Persse, D., Sterz, F., Lozano, M., Brouwer, M. A., ... & Travis, D. T. (2014). Manual vs. integrated automatic load-distributing band CPR with equal survival after out of hospital cardiac arrest. The randomized CIRC trial. Resuscitation, 85(6), 741-748.

4. Rubertsson, S., Lindgren, E., Smekal, D., Östlund, O., Silfverstolpe, J., Lichtveld, R. A., ... & Halliwell, D. (2014). Mechanical chest compressions and simultaneous defibrillation vs conventional cardiopulmonary resuscitation in out-of-hospital cardiac arrest: the LINC randomized trial. Jama, 311(1), 53-61.

5. Perkins, G. D., Lall, R., Quinn, T., Deakin, C. D., Cooke, M. W., Horton, J., ... & Smyth, M. (2015). Mechanical versus manual chest compression for out-of-hospital cardiac arrest (PARAMEDIC): a pragmatic, cluster randomised controlled trial. The Lancet, 385(9972), 947-955.

6. Bonnes, J. L., Brouwer, M. A., Navarese, E. P., Verhaert, D. V., Verheugt, F. W., Smeets, J. L., & de Boer, M. J. (2016). Manual cardiopulmonary resuscitation versus CPR including a mechanical chest compression device in out-of-hospital cardiac arrest: a comprehensive meta-analysis from randomized and observational studies. Annals of emergency medicine, 67(3), 349-360.

7. Gates, S., Quinn, T., Deakin, C. D., Blair, L., Couper, K., & Perkins, G. D. (2015). Mechanical chest compression for out of hospital cardiac arrest: systematic review and meta-analysis. Resuscitation, 94, 91-97.

8. Youngquist, S. T., Ockerse, P., Hartsell, S., Stratford, C., & Taillac, P. (2016). Mechanical chest compression devices are associated with poor neurological survival in a statewide registry: A propensity score analysis. Resuscitation, 106, 102-107.

9. Buckler, D. G., Burke, R. V., Naim, M. Y., MacPherson, A., Bradley, R. N., Abella, B. S., & Rossano, J. W. (2016). Association of Mechanical Cardiopulmonary Resuscitation Device Use With Cardiac Arrest Outcomes. Circulation, 134(25), 2131-2133.

10. Stub, D., Bernard, S., Pellegrino, V., Smith, K., Walker, T., Sheldrake, J., ... & Cameron, P. (2015). Refractory cardiac arrest treated with mechanical CPR, hypothermia, ECMO and early reperfusion (the CHEER trial). Resuscitation, 86, 88-94.

Be All End-Tidal: The Expanding Role of Capnography in Prehospital Care

by Adam Rieves, MD (@AdamRieves) and Brandon Bleess, MD (@BBBleess)

EMS MEd Editor: Maia Dorsett (@maiadorsett)

Clinical Scenario: EMS is called to the home of an elderly gentleman with altered mental status. On arrival, they find an elderly male who is muttering to himself. Per his daughter, he has had decreased oral intake and confusion over the last day. His vital signs include a heart rate of 95, blood pressure of 96/40, RR of 32 and an oxygen saturation of 89% on room air. His finger stick blood sugar is 178. The paramedics suspect severe sepsis. Since sepsis is a time-sensitive diagnosis, they wonder whether capnography would be helpful in the care for their patient now and subsequently in the hospital.

Literature Review: The capnograph represents continuous monitoring of the partial pressure of CO2 in a circuit and has four main phases [1]. The first phase (phase 1) represents the end of a breath; this is dead-space ventilation, meaning air that did not participate in gas exchange is cleared from the airways. Phase 2 is a rapid up-tick in the amount of CO2 measured which represents the first gas that is being sampled from the alveoli, i.e. initial exhalation. Phase 3 is known as the “alveolar plateau”. It represents the amount of CO2 in all the alveoli, on average. This plateau should have a slightly positive inclination due to the continuous excretion of CO2 into the alveoli becoming progressively smaller and the late emptying alveoli with a low V/Q ratio containing a relatively higher concentration of CO2. The value displayed on the monitor is equal to the end-tidal CO2 measured at the end of Phase 3. This is when the CO2 concentration reaches a maximum at the end of exhalation and reflects the CO2 concentration of the alveoli emptying last. The last phase (phase 0) of the waveform represents inhalation. Given the change in flow and there is minimal CO2 in the ambient air, the level measured by the detector quickly falls to near zero.

Similar to the role of pulse oximetry in guiding the prehospital provider through both management decisions and differential diagnosis, end-tidal capnography can provide invaluable physiologic information that can be used to enhance prehospital patient care in both intubated and non-intubated patients. .

ETT Placement & Integrity of the Respiratory Circuit

Capnography is the most reliable method to confirm endotracheal tube placement in the pre-hospital setting. In a 2001 study of 345 intubations, capnography had a sensitivity and specificity of 100% for correct placement. It was also found to be better than capnometry (qualitative) given that capnometry had a sensitivity of only 88% in cardiac arrest [3]. This was again demonstrated in a 2005 study of 153 patients intubated in the pre-hospital setting; the incidence of unrecognized esophageal intubations was 0% in patients with continuous EtCO2 monitoring versus 23.3% when continuous EtCO2 monitoring was not used [4].

Beyond initial confirmation of correct placement, capnography provides a continuous assurance of functional tube placement. After initial placement, loss of the waveform can indicate movement of the tube, possible esophageal placement or circuit disconnection. EtCO2 monitoring will also recognize dislodgement or apnea immediately compared to several minutes for the pulse oximeter to recognize desaturation. Given that endotracheal tubes can move upwards of 3 cm with neck extension, patient movement alone can cause tube dislodgement which could go unidentified without continuous EtCO2 monitoring [2]. Therefore, continuous waveform capnography for all patients with an advanced airway can be viewed as standard of care.

Uses in Cardiac Arrest

Because EtCO2 is a surrogate for perfusion, capnography can be used during CPR to monitor the effectiveness of resuscitative efforts. Continuous EtCO2 during resuscitation is associated with an improved rate of ROSC compared to no reported physiologic monitoring [12]. Furthermore, EtCO2>10 mmHg during CPRis associated with improved rates of patient survival to hospital discharge and survival with favorable neurological outcome [12]. A recent meta-analysis of 20 studies determined the average EtCO2 values of patients with ROSC versus those without. This study demonstrated that the mean EtCO2 in participants with ROSC was 25.8 ± 9.8 mmHg versus 13.1 ± 8.2 mmHg in those without ROSC. The mean difference in EtCO2 between those patients who achieved ROSC and those that did not was 12.7 mmHg (95% confidence interval: 10.3-15.1), suggesting that the AHA guidelines of a threshold of 10 to 20 mm Hg during resuscitation may need to be higher [13].

Moreover, EtCO2 is useful in guiding when resuscitative efforts are unlikely to be successful. In 1997 Levine et al. found that in patients with CPR duration > 20 minutes, EtCO2 averaged 4.4 ± 2.9 mmHg (Range 0-10) in non-survivors and 32.8 ± 7.4 mmHg (Range 18-58) in survivors to hospital admission. They also found that a 20-minute EtCO2 value of < 10 mm Hg successfully discriminated between patients who survived to hospital admission and non-survivors. In fact, the sensitivity, specificity, positive predictive value, and negative predictive value were all 100% [8]. This was duplicated in a pre-hospital study by Kolar et al. in 2008 which found thatafter 20 minutes of advanced life support, EtCO2 averaged 6.9 mmHg in patients who did not achieve ROSC and 32.8 mmHg in those who did. A 20-minute EtCO2 value of ≤14.3 mmHg successfully discriminated between ROSC and no ROSC with a sensitivity, specificity, positive predictive value, and negative predictive value of 100% [9]. Reflective of this, the current American Heart Association Guidelines state that, “In intubated patients, failure to achieve an ETCO2 of greater than 10 mm Hg by waveform capnography after 20 minutes of CPR may be considered as one component of a multimodal approach to decide when to end resuscitative efforts but should not be used in isolation.” [10,11]

Metabolic Derangements

DKA

End-tidal capnography has demonstrated great promise for assessment of metabolic derangements. A 2015 research study evaluated end-tidal CO2 as a screening tool for diabetic ketoacidosis (DKA). [14] Among patients presenting to the emergency department with a glucose greater than 550 mg/dL, an EtCO2 ≤ 21 mmHg was 100% specific for DKA. Moreover, an EtCO2 ≥ 35 mmHg allowed DKA to be ruled out with a sensitivity of 100 %. [14] In 2013, Soleimanpour et al. demonstrated that EtCO2 values more than 24.5 mmHg could rule out the DKA diagnosis with a sensitivity and specificity of 90% in patients with a glucose greater than 250 mg/dL [15]. A 2002 study evaluated the usefulness of EtCO2 for identifying acidosis in pediatric patients with hyperglycemia. It demonstrated that EtCO2 is linearly related to HCO3 and is significantly lower in children with DKA. An EtCO2 cut-point of <29 mmHg demonstrated a sensitivity and specificity of 83% and 100% respectively for DKA while an EtCO2 of ≥36 mmHg effectively ruled out DKA. [16]

Severe Sepsis

Severe sepsis and septic shock are time-critical diagnoses. Prehospital activation of a Code Sepsis Alert for patients with severe sepsis has been shown to improve mortality. [17] Severe sepsis is infection with associated end-organ dysfunction – of which one measure of is lactic acidosis due to anaerobic metabolism in the context of poor end-organ perfusion. Several prehospital screens have utilized prehospital lactate, but the lack of availability and prohibitive cost of lactate meters have prevented this from being widely available.

Figures. From Hunter CL, Silvestri S, Dean M, Falk JL, Papa L. End-tidal carbon dioxide is associated with mortality and lactate in patients with suspected sepsis. American Journal of Emergency Medicine. 2013 Jan; 31(1):64-71. — Figures. From Hunter CL, Silvestri S, Dean M, Falk JL, Papa L. End-tidal carbon dioxide is associated with mortality and lactate in patients with suspected sepsis. *American Journal of Emergency Medicine*. 2013 Jan; 31(1):64-71.

EtCO2 monitoring may serve as a useful surrogate for lactate measurement as it can evaluate for the respiratory compensation in response to the metabolic acidosis. In a 2013 study, Hunter et al. demonstrated that EtCO2 concentration may perform similarly to lactate levels as a predictor for mortality in patients with suspected sepsis [18]. They found an inverse relationship between exhaled EtCO2 levels and serum lactate levels; non-survivors had lower EtCO2 on arrival (26 mmHg) compared to survivors (30 mmHg) [18].

As a follow-up, in 2016 Hunter et al. published a study that evaluated EtCO2 as a component of a prehospital screening tool for sepsis, severe sepsis, or septic shock patients. If the patient met the following criteria: 1. Suspected infection, 2. Two or more of the SIRS criteria (Temperature not between 36°C and 38°C, respiratory rate > 20, heart rate greater than 90) and 3. EtCO2 < 25 mmHg, the ED was notified of a “Sepsis Alert.” This protocol was 90% sensitive, 58% specific and had a negative predictive value of 93% for severe sepsis. Among all prehospital variables, low EtCO2 levels were the strongest predictor of sepsis, severe sepsis, and mortality. There were significant associations between prehospital EtCO2 and serum bicarbonate levels, anion gap, and lactate [19].

MCI Triage

Since the terrorist attacks of September 11, 2001, emergency medical services systems have had continued focus in preparation for a terrorism event causing an MCI. Capnography is a single monitoring modality that can provide assessment of the ABCs in less than 15 seconds. The presence of a normal waveform allows the provider to know that the patient is breathing and the airway is patent. A normal EtCO2 level (35-45 mm Hg) signifies adequate ventilation and perfusion. Furthermore, capnography can allow for rapid assessment of common complications of chemical agents including: apnea, upper airway obstruction, laryngospasm, bronchospasm, and respiratory failure. The absence of the capnogram, in association with the presence or absence of chest wall movement, distinguishes apnea from upper airway obstruction and laryngospasm. Response to airway alignment maneuvers (chin lift, jaw thrust) can further distinguish upper airway obstruction from laryngospasm [6]. Given its usefulness in rapid assessment of the ABCs and ability to identify common complications of chemical terrorism, “EMS systems should consider adding capnography to their triage and patient assessment toolbox and emphasize its use during educational programs and MCI drills.”[7]

Limitations

End-tidal CO2 levels do not necessarily correspond to paCO2 levels obtained on an arterial blood gas. In patients that have abnormal lung function, the gradient will widen depending on the severity of the lung disease. EtCO2 in patients with lung disease, such as an obstructive lung disease, is only useful for trending ventilatory status over time; not as a single number spot check that may or may not correlate with the pCO2 [20,21].

Conclusions

Capnography in EMS has evolved substantially from its origins as a qualitative color change pH indicator to identify successful endotracheal intubation. What once was a tool just for anesthesia in the Operating Room has become a transformative tool in the pre-hospital setting. Uses have evolved to include early recognition of respiratory inadequacy and failure, integrity of the ventilator circuit, identification of a dangerous inhalation and triage, adequacy of resuscitation during cardiac arrest including detection of ROSC, prediction of diabetic ketoacidosis and early identification and treatment sepsis. Given this, capnography has the opportunity to become as indispensable as the cardiac monitor in the pre-hospital management of many conditions.

References

1. Bhavani-Shankar K, Philip JH. Defining segments and phases of a time capnogram. Anesthesia and Analgesia 2000;(4):973-7

2. Kim JT, Kim HJ, Ahn W, et al.. Head rotation, flexion, and extension alter endotracheal tube position in adults and children. Can J Anaesth.2009;56(10):751–756.

3. Grmec S. Comparison of three different methods to confirm tracheal tube placement in emergency intubation. Intensive Care Med. 2002;28:701–4.

4. Silvestri S, Ralls GA, Krauss B, et al. The effectiveness of outof-hospital use of continuous end-tidal carbon dioxide monitoring on the rate of unrecognized misplaced intubation within a regional emergency medical services system. Ann Emerg Med. 2005;45:497–503.

5. Krauss B. Capnography as a rapid assessment and triage tool for chemical terrorism. Pediatr Emerg Care, 2005; 21:493-497.

6. Krauss B. Advances in the Use of Capnography for Nonintubated Patients. Israeli Journal of Emergency Medicine. 2008;8:3–15.

7. Krauss B, Heightman AJ. 15-second triage tool. The use of capnography for the rapid assessment & triage of critically injured patients & victims of chemical terrorism. JEMS. 2006 Jun;31(6):60-2, 64-6, 68.

8. Levine RL, Wayne MA, Miller CC. End-tidal carbon dioxide and outcome of out-of-hospital cardiac arrest. N Engl J Med. 1997 Jul 31;337(5):301-6.

9. Kolar M, Krizmaric M, Klemen P, Grmec S. Partial pressure of end-tidal carbon dioxide successful predicts cardiopulmonary resuscitation in the field: a prospective observational study. Crit Care. 2008;12(5):R115. doi: 10.1186/cc7009. Epub 2008 Sep 11.

10. Hazinski MF, Nolan JP, Aicken R, et al. Part 1: executive summary: 2015 International Consensus on Cardiopulmonary Resuscitation and Emergency Cardiovascular Care Science With Treatment Recommendations. Circulation. 2015;132(16)(suppl 1).

11. Neumar RW, Shuster M, Callaway CW, et al. Part 1: executive summary: 2015 American Heart Association Guidelines Update for Cardiopulmonary Resuscitation and Emergency Cardiovascular Care. Circulation. 2015;132(18)(suppl 2).

12. Sutton RM, French B, Meaney PA, Topjian AA, Parshuram CS, Edelson DP, Schexnayder S, Abella BS, Merchant RM, Bembea M, Berg RA, Nadkarni VM. Physiologic monitoring of CPR quality during adult cardiac arrest: A propensity-matched cohort study. Resuscitation. 2016 Sep;106:76-82. doi: 10.1016/j.resuscitation.2016.06.018. Epub 2016 Jun 24.

13. Hartmann SM, Farris RW, Di Gennaro JL, Roberts JS. Systematic Review and Meta-Analysis of End-Tidal Carbon Dioxide Values Associated With Return of Spontaneous Circulation During Cardiopulmonary Resuscitation. J Intensive Care Med. 2015 Oct;30(7):426-35. doi: 10.1177/0885066614530839. Epub 2014 Apr 22.

14. Bou Chebl R, Madden B, Belsky J, Harmouche E, Yessayan L. Diagnostic value of end tidal capnography in patients with hyperglycemia in the emergency department. BMC Emerg Med. 2016 Jan 29;16:7. doi: 10.1186/s12873-016-0072-7.

15. Soleimanpour H, Taghizadieh A, Niafar M, Rahmani F, Golzari SE, Esfanjani RM. Predictive value of capnography for suspected diabetic ketoacidosis in the emergency department. West J Emerg Med. 2013;14(6):590–4.

16. Fearon DM, Steele DW. End-tidal carbon dioxide predicts the presence and severity of acidosis in children with diabetes. Acad Emerg Med. 2002;9(12):1373–8.

17. Guerra, W. F., Mayfield, T. R., Meyers, M. S., Clouatre, A. E., & Riccio, J. C. (2013). Early detection and treatment of patients with severe sepsis by prehospital personnel. The Journal of emergency medicine, 44(6), 1116-1125.)

18. Hunter CL, Silvestri S, Dean M, Falk JL, Papa L. End-tidal carbon dioxide is associated with mortality and lactate in patients with suspected sepsis. American Journal of Emergency Medicine. 2013 Jan; 31(1):64-71.

19. Hunter CL, Silvestri S, Ralls R, Stone A, Walker A, Papa L. A prehospital screening tool utilizing end-tidal carbon dioxide predicts sepsis and severe sepsis. American Journal of Emergency Medicine. 2016 May; 34(5):813-819.

20. Yamanaka MK, Sue DY. Comparison of arterial-end-tidal Pco2 difference and dead space/tidal volume ratio in respiratory failure. Chest. 1987;92:832-835.

21. Hardman JG, Aitkenhead AR. Estimating alveolar dead space from the arterial to end-tidal CO2 gradient: a modeling analysis. Anesth Analg. 2003;97:1846-1851.

Additional articles of Interest:

EMS One: 5 Things to Know About Capnography in Cardiac Arrest

Yes or No? Prehospital Endotracheal Intubation For Patients With Traumatic Brain Injury

by Kevin Baumgartner, MD

EMS MEd Editor: Maia Dorsett (@maiadorsett)

Case: EMS is dispatched to the scene of a Motor Vehicle Accident. They arrive to find a 45 year old male who was riding his bicycle when he was hit by a car traveling at approximately 35 mph. Eyewitnesses state that the man was thrown from his bicycle and hit his head on the pavement. On their initial assessment, paramedics find a poorly responsive middle-aged male who will not open eyes spontaneously, makes no verbal response but withdraws to painful stimuli. He has obvious head trauma with a large hematoma and laceration overlying his parietal scalp. The patient has rapid and shallow spontaneous respirations and the paramedics need to decide how to best manage his airway during their twenty minute transport to the local trauma center.

Clinical Question: Do patients with severe traumatic brain injury benefit from prehospital intubation?

Literature Review:

Airway management is a cornerstone of both basic and advanced life support. Paramedics and other EMS providers frequently encounter patients who can no longer protect their own airways (traumatic brain injury, major polytrauma, intoxication and overdose) or who are experiencing impending respiratory failure (exacerbations of congestive heart failure and obstructive lung disease). In-hospital management for these patients typically includes endotracheal intubation (ETI), which provides definitive control of the airway, reduces aspiration risk, and allows for mechanical ventilatory support. Do any of these patients benefit from pre-hospital ETI? Should EMS providers intubate in the field, or should they use airway adjuncts such as bag-valve mask ventilation, supraglottic airway devices, or non-invasive positive pressure ventilation to temporize their patients during rapid transport to the hospital?

As one might expect, the data on this issue are mixed and generally poor in quality. Given the ethical and logistical difficulties involved in designing true randomized controlled trials of field vs. in-hospital ETI, most research has been retrospective and observational. As Pepe and colleagues point out in their 2015 review, patients who are intubated in the field are almost by definition the sickest patients encountered by EMS providers; as such, any naïve univariate analysis will almost certainly find that prehospital ETI is associated with poor outcomes [1].

Pepe and colleagues also note that success of prehospital ETI (and thus overall patient outcomes) is strongly influenced by the type, intensity, and duration of training that is provided for EMS personnel, as well as the structure of the individual EMS service being studied. This intuitive conclusion was reinforced by a 2015 meta-analysis by Bossers and colleagues, which demonstrated that prehospital ETI by EMS providers with “limited proficiency” was associated with increased mortality (OR 2.33, 95% CI 1.61-3.38), while prehospital ETI by EMS providers with “extended proficiency” was not associated with increased mortality [2]. Given the relative rarity of pre-hospital ETI (“critical procedures” including ETI, cardioversion, and defibrillation were performed during only 2.4% of EMS calls in 2011) and the difficulty of allowing a large pool of EMS providers sufficient access to clinical situations requiring ETI, it can be very challenging to allow EMS personnel to acquire the “extended” skills required for routinely successful ETI [1,3].

Pre-hospital ETI has been studied in specific clinical contexts. Severe traumatic brain injury (TBI) frequently robs patients of the ability to protect their own airway from aspiration and oral secretions. Furthermore, every effort must be taken to ensure adequate oxygenation as hypoxia in itself can lead to secondary brain injury and worsen patient outcomes. Unfortunately, the literature is ambivalent on the value of pre-hospital ETI in this population; an abundance of studies suggest that pre-hospital ETI does not improve outcomes, and some suggest that it may actually worsen outcomes. One retrospective cohort study, for example, showed that timing of ETI (pre-hospital vs. in ED) had no effect on mortality in TBI patients [4]. As mentioned above, one large meta-analysis showed no influence of pre-hospital ETI on mortality when ETI was performed by experienced providers [2]. A Californian retrospective case-control study showed that patients with severe TBI managed with pre-hospital ETI had higher mortality and worse admission pO2 than patients who underwent only BLS airway interventions [5]. A cohort-matched retrospective study involving over twenty-seven thousand patients demonstrated that pre-hospital ETI was independently associated with higher in-hospital mortality (OR 1.399, 95% CI 1.205-1.624) [6]. In the OPALS study comparing survival before and after the introduction of Advanced Life support, patients with severe TBI has a lower survival rate during the advanced life-support phase (50.9% vs. 60.0%; P = 0.02) [7]. Indeed, a systematic review of 13 studies on prehospital intubation for TBI published in 2008 found the unadjusted ORs for an effect of pre-hospital intubation on in-hospital mortality varied widely, ranging from 0.17 (95% CI: 0.10–0.31) to 2.43 (95% CI: 1.78–3.33) [8].

While the majority of studies on prehospital intubation for TBI are retrospective or observational, a prospective, randomized control trial of prehospital intubation vs transport and intubation in ED for patients with severe TBI was completed in Australia [9]. The trial included 312 patients with a GCS < 9, evidence of head trauma, age ≥15 years and intact airway reflexes. Patients randomized to undergo prehospital intubation underwent RSI with fentanyl/versed/succinylcholine and subsequent sedation/paralysis with a single dose of pancuronium (0.1 mg/kg), and an intravenous infusion of morphine and midazolam at 5 to 10 mg/h each after confirmation of successful endotracheal tube placement. The primary outcome was neurologic outcome at 6 months post-injury. Using the extended Glasgow Outcome Scale (eGOS) as this measureable outcome, the study found that the median eGOS for patients who underwent prehospital intubation was 5 (moderate disability), while those who underwent hospital intubation had a median eGOS of 3 (severe disability). This difference was not significant (p = 0. 28). There was a significant difference in "good neurologic outcome" (defined as eGOS 5-8) between the two groups (51% prehospital intubation vs. 39% hospital intubation, p = 0.046), but 13 patients were lost to follow-up, the majority of which were in the hospital intubation group. While this study suggests that there may be a benefit of prehospital intubation for patients with severe brain injury, there are important differences between the study and average prehospital practice. First, intubation success rate was 97%. Reports of success rates for prehospital intubation in North America are generally lower, ranging from 83 to 97% [10,11,12]. Second, they had full RSI (sedative and paralytic) as well as post-intubation sedation that would inhibit disadvantageous consequences such as coughing in a severely brain-injured patient.

Table 3 from: Bernard, S. A., Nguyen, V., Cameron, P., Masci, K., Fitzgerald, M., Cooper, D. J., ... & Patrick, I. Prehospital rapid sequence intubation improves functional outcome for patients with severe traumatic brain injury: a randomized co… — Table 3 from: Bernard, S. A., Nguyen, V., Cameron, P., Masci, K., Fitzgerald, M., Cooper, D. J., ... & Patrick, I. Prehospital rapid sequence intubation improves functional outcome for patients with severe traumatic brain injury: a randomized controlled trial. *Annals of surgery*, 2010; 252(6), 959-965

Given the available data, it is reasonable to conclude that pre-hospital ETI in patients with TBI does not improve relevant patient-centered outcomes in most prehospital settings. It is unclear why this is true—possible explanations include delay of transport to definitive care (multiple studies demonstrated increased scene times in patients undergoing ETI), greater willingness on the part of EMS personnel to intubate patients who are overall “sicker,” hypoxia during intubation attempts, hyperventilation leading to decreased cerebral perfusion or simply the high success rate of non-invasive ventilation and oxygenation strategies in this patient population [4,7,13]. At least when it comes to ground transport, where invasive airways are less necessary and overall frequency of intubation as a procedure low, BVM or supraglottic devices may be the preferred method of airway management for patients with severe TBI.

References

1. Pepe et al. Prehospital endotracheal intubation: elemental or detrimental? Crit Care. 2015; 19(1): 121

2. Bossers et al. Experience in Prehospital Endotracheal Intubation Significantly Influences Mortality of Patients with Severe Traumatic Brain Injury: A Systematic Review and Meta-Analysis. PLoS One. 2015; 10(10): e0141034.

3. Carlson et al. Procedures Performed by Emergency Medical Services in the United States. Prehosp Emerg Care. 2016;20(1):15-21.

4. Lansom et al. The Effect of Prehospital Intubation on Treatment Times in Patients With Suspected Traumatic Brain Injury. Air Med J. 2016 Sep-Oct;35(5):295-300

5. Karamanos et al. Is prehospital endotracheal intubation associated with improved outcomes in isolated severe head injury? A matched cohort analysis. Prehosp Disaster Med. 2014 Feb;29(1):32-6

6. Haltmeier et al. Prehospital intubation for isolated severe blunt traumatic brain injury: worse outcomes and higher mortality. Eur J Trauma Emerg Surg. 2016 Aug 27

7.Stiell IG, Nesbitt LP, Pickett W; OPALS Major Trauma Study Group. Impact of advanced life-support on survival and morbidity. CMAJ. 2008;178:1141– 1152.

8. Von Elm, E., Schoettker, P., Henzi, I., Osterwalder, J., & Walder, B. Pre-hospital tracheal intubation in patients with traumatic brain injury: systematic review of current evidence. British journal of anaesthesia, 2009; 103(3), 371-386.

9. Bernard, S. A., Nguyen, V., Cameron, P., Masci, K., Fitzgerald, M., Cooper, D. J., ... & Patrick, I. Prehospital rapid sequence intubation improves functional outcome for patients with severe traumatic brain injury: a randomized controlled trial. Annals of surgery, 2010; 252(6), 959-965.

10. Bernard S, Smith K, Foster S, Hogan P, Patrick I. The use of rapid sequence intubation by ambulance paramedics for patients with severe head injury. Emerg. Med. 2002; 14: 406–11.

11.Davis DP, Hoyt DB, Ochs M et al. The effect of paramedic rapid sequence intubation on outcome in patients with severe trau- matic brain injury. J. Trauma 2003; 54: 444–53.

12. Wayne MA, Friedland E. Prehospital use of succinylcholine: a 20 year review. Prehosp. Emerg. Care 1999; 3: 107–9.

13.Bernard, S. A. Paramedic intubation of patients with severe head injury: a review of current Australian practice and recommendations for change. Emergency Medicine Australasia, 2006; 18(3), 221-228.

It's Time For Us To Call a Code Green

by Clayton Kazan, MD

We all know about the various codes they call in the hospital: Code Blue, Code White, Code Pink, etc. We have even made up a few codes of our own, aka Code Brown. But, not enough of us know about Code Green. It's not a new name for patients on 4/20 or from Colorado or California. It's about recognizing the leading cause of active duty death in our First Responders...suicide.

I have come to believe strongly that we train ourselves and our EMS brothers and sisters the wrong way. When I look back on my training as an EMT (and Medical School and Residency), I received exactly zero training in mental resilience and zero preparation for the calamities I would bear witness to. In fact, my department followed a now discouraged practice of forcing us to see a psychologist for a debriefing after any traumatic call. Hopefully none of your departments still require critical incident stress debriefing since we now know that forcing it upon our folks can be counter-productive. But, what can we do, because we need to do something...the data is staggering.

According to the Firefighter Behavioral Health Alliance (FBHA), from 2014-2016, there have been 374 suicides among active duty firefighters, compared with 268 Line of Duty Deaths (LODDs). This data likely understates the problem, since data for suicides is shared voluntarily while LODDs are reported mandatorily to NIOSH. Research has shown that first responders' rate of suicidal ideation is 10x that of the general public, while firefighters' rate is more than 12x. The risk of suicide attempts is 13x higher for first responders and 30x higher for firefighters. The risk of successful suicide is more than 2.5x that of the general public. And, unfortunately, the data is not much better for us Medical Directors because Emergency Physicians also have an increased risk of suicide, though not as bad as the first responders.

I think that the problem boils down to 2 cultural issues we need to face. First, we need to reconsider the whole way we think about the horrible things we experience. We all carry with us the memories of the horrific tragedies we have cared for, the mistakes we have made, the times we have been threatened or assaulted, and we have all experienced having to suppress our emotions for the sake of moving on to the next patient. We see things and experience emotions, quite often, that the lay public never experiences. No matter how resilient you may be, these exposures leaveboth temporary and permanent impressions upon your soul.

What do we do to prepare our folks during their training, and how good are we at monitoring our crews throughout their careers? The military, faced with a suicide epidemic, has incorporated resiliency training to soldiers preparing for deployments, and they have seen some decrease in post-traumatic stress disorder (PTSD). While EMS has embraced many military technologies and practices into everyday care, resiliency training has lagged behind. There are many healthy ways we use to cope every day, including the tight comeradery among us. Many of our departments, mine included, have incorporated Peer Health Counsellors, Chaplains, and access to Psychologists, but it is still largely dependent on self-referral. Unfortunately, beyond the comeradery of our profession, the culture also includes some worrisome practices. Substance abuse is high, especially with the work hard-play hard mentality. The same comeradery that binds us can lead folks that need help to be afraid to ask for it because they are afraid of being ostracized, thought of as weak, of being laughed at, or of being fired. And so, they laugh at our jokes and sit quietly during our stories, and they begin to isolate themselves. After all, they signed up for this, and working in EMS becomes more than your profession. It becomes who you are, and what if you don't know if you can continue to be who you are anymore?

The other cultural problem that we need to face is the way we treat errors. This is not unique to EMS and is true throughout the practice of medicine. I think that we all tire of the analogies to the airline industry, but the success of their cultural change around safety has been remarkable. In my own department, if we avoid serious mistakes 99.99% of the time, then we will still commit 36/year...a number that most critics would argue is far too high. But, can anyone really expect even that level of performance from human beings? We need to get out of the cycle of our name, blame, and train approach to performance improvement. No system punishes its way to greatness. In fact, only a poorly designed system would ever allow a single, unchecked mistake by a provider to lead to a patient catastrophe. Our culture of punishing for mistakes only leads to their concealment for fear of reprisal, and so our system remains stagnant rather than getting safer. We set such unrealistically high expectations for our folks, that the guilt of a mistake reaps a terrible toll on our folks, and they practice in fear. In the words of Jeff Skiles, the lesser known co-pilot of the USAir plane that landed in the Hudson River, "It is vastly more important to identify the hazards and threats to safety than to identify and punish an individual for a mistake."

So, what are the answers? We need to educate ourselves and our folks about the warning signs of our brothers and sisters in crisis. We have to educate them early in their careers and renew it often, and we need to maintain a culture that encourages members in crisis to step forward. We must build layers into our systems to protect both our patients and our caregivers, because no individual error should ever lead to catastrophe. That way, the crews on the front lines can step forward and help us build a safer system rather than practicing in fear of making a catastrophic mistake. Lastly, let's mobilize behind the critical work of organizations like the Code Green Campaign, FireStrong, etc. and make sure that our folks all know that they are out there.

We must all remember that we are all vulnerable to mental illness. The burden of our deceased brethren was not unique to them. Sometimes it just takes one bad experience to put us over the edge. It happens to folks in the beginning, middle, and end of their careers, and it can progress rapidly. There are often warning signs, and there may be an opportunity to intervene and get them the help they need. What sets them apart is not their circumstance, it's that we did not recognize their crisis and respond to them in time. Suicidal ideation is a treatable illness, and suicide is preventable.

Please check out these excellent and important organizations:

Code Green Campaign

Firestrong

Can Negativity be a Good thing? The Impedance Threshold Device in CPR.

by Zachary Hafez MD & Melissa Kroll MD

expert reviewed by Hawnwan Philip Moy MD (@pecpodcast)

It's a slow Saturday morning and you as the medical director are riding out enjoying the unusually warm 60 degree weather...in February no less! To celebrate, you decide to visit your favorite coffee shop and get the world's best latte. Just as you pull in, dispatch suddenly pages out a 58-year-old male in cardiac arrest. It looks like your coffee is going to have to wait...but don't worry, you'll be receiving your daily dose of adrenaline soon.

When you arrive 5 minutes later, the first responders and paramedics are already hard at work pit crewing away. On an initial survey, you notice an odd appearing plastic device with flashing lights. Having read about them before, you ask your first responder where the Impedance Threshold Device (ITD) came from? Apparently, one of your Emergency Medical Response Agencies (EMRAs) is trialing ITDs. "We got a pulse!" exclaims one of your medics. As everyone breaths a sigh of relief, your fire first responder wipes her brow and asks, "So doc...what do you think of the ITD?" Before answering, you quickly try to buy some time by helping your crews prepare for transport and scramble to recount the evidence behind ITDs and cardiac arrest...

Background

In 1960 the American Heart Association (AHA) introduced cardiopulmonary resuscitation (CPR) to physicians and thereby becoming the premier educator in CPR training. Despite multiple advances in ACLS over the last 50 years, only modest improvement in survival rates have been achieved. In 2011, EMS responded to over 326,000 out-of-hospital cardiac arrests in the United States with a survival to hospital discharge of only 10.6% [1].

The reason for the lack of improvements in survival is multifactorial. Standard CPR is inherently less effective than a beating heart providing less than 25% of normal blood flow to the heart and brain [2]. Furthermore, the resuscitation is often limited by inadequate CPR, namely incomplete chest compression and chest recoil [3, 4, 5]. One of the more recent developments to augment the effect of CPR is the impedance threshold device (ITD).

Physiology of CPR and the Role of the ITD

The goal of CPR is to circulate blood from the heart to the body during chest compression and allow return of blood back to the heart during chest recoil. There are two predominantly accepted theories that explain how this may occur [6]. The first is the “cardiac pump theory” which is based on the principle that the heart is compressed between the sternum and vertebral column leading to mechanical ejection of the blood from the heart [7]. The second is the “thoracic pump theory” which is based on the principle that the thoracic cavity is a confined space whereby compression of the chest wall leads to an increase in intrathoracic pressure that causes ejection of blood from the heart into the systemic circulation and expiration of air from the lungs [8]. Decompression of the chest wall (i.e. natural chest recoil) leads to a decrease in intrathoracic pressure, resulting in venous return of blood. However, the hemodynamic gradient of the vacuum is attenuated by passive inspiration of air that occurs with chest recoil.

The ITD is designed to limit this passive inspiration of air during CPR. It is a disposable, plastic, cylindrical shaped device containing a silicon diaphragm which works as a one-way valve that can be attached to an endotracheal tube, laryngeal mask airway, or bag valve mask in line with the airway circuit. During chest compression, intrathoracic pressure becomes higher than atmospheric pressure opening the unidirectional valve and air is freely expired from the lung. During chest recoil, the intrathoracic pressure falls below atmospheric pressure leading to valve closure. A closed valve prevents air in the airway circuit from re-entering the lungs preserving a negatively pressured intrathoracic cavity.

Creating a negatively pressured intrathoracic cavity, potentially leads to two primary circulatory benefits. First, the vacuum within the chest enhances venous return to the right side of the heart, which leads to increases in preload, systolic blood pressure, circulation, and ultimately priming the heart for the next compression. Second, use of the ITD reduces intracranial pressures more rapidly and to a greater degree during the decompression phase of CPR by maintaining lower intrathoracic pressures. This provides less resistance to cerebral perfusion during the next compression5. This leads to improved perfusion of the brain.

Literature Review

In 1995, Lurie demonstrated that the use of ITDs with CPR improved coronary perfusion pressures and a decreased in the number of defibrillation during resuscitation of swine models [9]. Even though the study only included 15 animals, it prompted discussion and future studies on the applicability of ITDs in cardiac arrest resuscitations Later, Mader et al performed a blinded, randomized controlled study with swine models. This study demonstrated that ITDs improved both coronary perfusion pressure and ventilation as measured by PaCO2, PaO2, and arterial pressures of the chest during standard CPR [10]. However, not all studies showed benefits associated with the use of an ITD. A study performed by Menegazzi et. al, unfortunately discovered that by adding ITDs to their standard CPR, there was a reduced survival rate of ventricular tachycardia in 36 randomized pigs (33% survival in the pigs that were revived with an ITD compared to 78% in pigs who were revived with standard CPR practices) [11].

Complicating the issue further was the inclusion of active CPR (compression-decompression) compared to standard CPR in subsequent ITD studies. Active CPR was first researched after a man successfully performed high-quality CPR with a plunger at home during a cardiac arrest. It is believed that during active CPR, forced recoiling of the chest wall increases the negative pressure in the intrathoracic cavity and, in effect, improving venous blood return. Thus, adding an ITD to active CPR would further potentiate a negative intrathoracic pressure and increase blood return. The combination of Active CPR with ITDs was first studied by Shih et. al. by using ITDs in conjunction with a novel adhesive glove device to provide active CPR on swine models. While the adhesive glove CPR improved flow with active compression-decompression, this study concluded that the addition of an ITD to the adhesive glove CPR had no statistical difference in perfusion compared to the adhesive glove CPR alone [12].

Despite Shih’s findings, Plaisance continued Shih’s thought process by studying ITD use with active CPR in human resuscitations. In 2000, Plaisance et al completed a prospective, randomized, blinded trial to compare active CPR to active CPR with the use of ITD [13]. Their use of the sham ITD allowed for blinding of the subjects and became the basis for most future blinded studies. The primary objective was to elucidate the effect of the ITD on end tidal CO2, diastolic blood pressure, coronary perfusion pressure, and return of spontaneous circulation (ROSC). Their results not only showed that the usage of an ITD with active CPR improved end tidal CO2 and mean peak arterial pressures, but also 70% higher mean coronary perfusion when compared to the control group. They further demonstrated a decreased time to ROSC in the patients with the ITD. Although the utilization of ITDs with active CPR appear to have a benefit based on this study, only 21 patients were included decreasing the strength of this study. A second study was performed by Plaisance in 2004, but this time the objective looked at 24-hour survival in 400 patients [14]. This study was also a randomized controlled double-blinded prospective trial comparing active CPR with ITD to active CPR alone. They found a statistically significant increase number of patients surviving to 24 hours when ITD was used (64% in the ITD group compared to 44% when active CPR is used alone; OR 1.67 [1.07-2.6]) compared to the control.

The early successes of the Plaisance trials were echoed by the prospective controlled trial performed by Wolcke et al in 2003. Wolcke et al performed a prospective controlled trial comparing standard CPR to active CPR with ITD [15]. Their primary end point was 1-hour survival and 24-hour survival. They noted that nearly twice as many witnessed arrest patients survived for 1 hour and 24 hours when active CPR with ITD was used as compared to standard CPR alone (OR 2.4 [1.28-4.62]). However, a major critique of this study is that the authors compared standard CPR against two different variables, active CPR and ITD use, leading to serious confounding variables. This limitation is echoed in future studies. Other critiques include the size of the study (only 200 patients) and the lack of blinding.

These previous studies were the backbone for the 2005 AHA guidelines recommending the use of ITD in resuscitations, despite the fact no long-term survival benefit had been demonstrated [16]. In an attempt to address this perceived deficiency, a systematic review and meta-analysis was performed by Cabrini et al in 2008. This analysis looked at 5 studies including 833 patients and found improved ROSC (46% for ITD compared to 36% control, relative risk 1.45 [1.16-1.80]) and early survival (32% in those with ITD use compared to 22% without, RR 2.35[1.30-4.24]) [17]. They did not find a benefit in survival at the longest available follow-up or in favorable neurologic outcome when looking at all survivors.

In an effort to find a difference between long-term survival and overall neurological outcome, a multi-center, randomized-controlled, blinded, prospective study was completed by Aufderheide et al. Over 1,600 patients from 7 different locations and 46 EMS agencies in the United States were selected with the exception of patients believed to have an arrest from non-cardiac causes [18]. They compared standard CPR to active CPR with ITD and found improvement in survival to hospital discharge with favorable neurological function when active CPR with ITD was used (6% in standard CPR compared to 9% in the active CPR with ITD [OR1.58; 1.07-2.36]). Additionally, a 1-year survival was improved when active CPR with ITD was used compared to standard CPR alone (9% vs 6%; p=0.03). A follow up study looking at all patients, from both cardiac and non-cardiac causes, found that while standard CPR and active CPR with ITD had similar rates of ROSC, the active CPR with ITD had a 38% increase survival to discharge with favorable neurological outcome (OR 1.42 [CI 1.04-1.95]) and a 39% relative increase in survival to 1 year. These studies were widely criticized for using the ITD in active CPR and comparing the results to standard CPR alone. The benefit of survival could not be attributed to the ITD alone, as active CPR may have been part (or all) of the benefit. Hmmm...

In response to criticisms, Aufderheide et al. performed the largest randomized, double blinded, prospective study comparing standard CPR with standard CPR with ITD with the objective of assessing survival to hospital discharge with a favorable neurological outcome (modified Rankin score of 3 or less), known as the ROC PRIMED trial [19]. The study included 10 sites across the US and Canada involving 8,718 patients. Surprisingly, this study showed no difference in survival to hospital discharge with favorable neurological outcome (6.0% in the standard CPR with sham ITD compared to 5.8% in the standard CPR with active ITD). To further support the findings in the NIH PRIMED trial a subsequent systematic review and meta-analysis was performed that showed no survival benefit [20]. The authors noted significant heterogeneity between studies and that the ROC PRIMED study was by far the largest, significantly weighing results. However, a sub-analysis looking at the use of ITD in active CPR found potential benefit. The authors noted an increased likelihood of ROSC (odds ratio=1.19 [1.00-1.40], p=0.045), favorable neurologic outcome (odds ratio=1.60 [1.14-2.25]), and long-term survival (odds ratio=1.52 [1.11-2.08]) in those patients resuscitated with an ITD. These findings are reflected in the newest AHA guidelines in which it states that “[t]he routine set of ITD as an adjunct during conventional CPR is not recommended. The combination of ITD with active compression decompression CPR may be a reasonable alternative to conventional CPR in settings with available equipment and properly trained personnel [Class III recommendation].” [21]

Despite the newest AHA recommendations, the discussion on the potential benefit of the ITD is far from over. Yannopoulos et al re-evaluated the data collected in the ROC PRIMED trial to evaluate the quality of CPR performed during the study [22]. They found that of the 8,719 patients in the study, only 1,675 had quality CPR recorded. Of those who received acceptable CPR, ITD use with standard CPR increased survival to hospital discharge with modified Rankin score equal or less than 3 (7.2% compared to 4.1%; p=0.007). However, when the quality of CPR was not acceptable, the group receiving standard CPR with the ITD had a worse survival to hospital discharge with good neurological outcome (3.4% compared to 5.8%; p=0.007).

The complex interplay between multiple factors was again supported by the most recent systematic review and meta-analysis performed by Wang et al [23]. This meta-analysis looked at 15 studies to evaluate if either active CPR or ITD showed benefit over standard CPR. They compared active to standard CPR, standard CPR to standard CPR with ITD, and standard CPR to active CPR with ITD. They found no benefit for ITD or active CPR. However, in a regression analysis they found the results of their analysis may have been mitigated by the confounding variables of witnessed arrest and response time. When those two factors were adjusted, they found improved ROSC with ITD and active CPR. The meta-analysis again noted heterogeneity between studies, but stated that the biggest effect on survival was actually witnessed arrest and response times.

Take Home Points

Although initial studies demonstrated great potential for the ITD, the current, more powered studies do not absolutely support the use of the ITD with standard CPR. The limited benefit of the ITD may be confounded by other factors affecting CPR, such as the depth and rate of chest compressions. Future studies may show a benefit for the ITD in quality CPR. There is a potential benefit for the use of the ITD in active CPR, but this benefit is questionable. It is also difficult to state that any survival benefit is from the ITD and not the active CPR. What can be said is that early, good chest compressions and CPR does in fact show benefit. Once an EMS system masters these crucial initial steps, then perhaps devices like the ITD and processes like active CPR can provide a meaningful outcome for your patients.

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References

1) Mozzaffarian D, Benjamin E, Go A. Heart Disease and Stroke Statistics-2015 Update. Circulation. 2015; 206-209.

2) Andreka P, Frenneaux M. Haemodynamics of cardiac arrest and resuscitation. Curr Opin Crit Care. 2006; 12:198-203.

3) Yannopolous D, Aufderheide T, Abella B, et al. Quality of CPR: An important effect modifier in cardiac arrest clinical outcomes and intervention effectiveness trials. Resuscitation. 2015; 94:106-113,

4) Aufderheide TP, Alexander C, Lick C, et al. From laboratory science to six emergency medical services systems: New understanding of the physiology of cardiopulmonary resuscitation increases survival rates after cardiac arrest. Brit Care Med October 2008;36(11)[Suppl.]S397-S404.

5) Schleien S, Berkowitz I, Trastman R, Rogers M. Controversial Issues in Cardiopulmonary Resuscitation. Anesthesiology. 1989; 71:133-149.

6) Jude W. Kouwenhoven W, Ing, Knickerbocker G. Cardiac Arrest. 1961; 178(11): 85-92.

7) Rudikoff M. Maughan L, Effron M, Freund P, Weisfeldt M. Mechanisms of Blood Flow During Cardiopulmonary Resuscitation. Circulation. 1980; 61(2):345-352. doi: 10.1161/01.CIR.61.2.345.

8) Lurie K, Coffeen P, Shultz J, McKnite S, Detloff B, Mulligan K. Improving Active Compression-Decompression Cardiopulmonary Resuscitation with an Inspiratory Impedance Valve. 1995;91:1629-1632. doi:10.1161/01.CIR.91.6.1629

9) Mader T, Kellogg A, Smith J, Decoteau R, et.al. A blinded, randomized controlled evaluation of an impedance threshold device during cardiopulmonary resuscitation in swine. Resuscitation 2008; 77:387-394.

10) Menegazzi JJ, Salcido DD, Menegazzi MT, et al. Effects of an impedance threshold device on hemodynamics and restoration of spontaneous circulation in prolonged porcine ventricular fibrillation. Prehosp Emerg Care. 2007; 11(2):179-85.

11) Shih A, Udassi S, Porvasnik S, et al. Use of Impedance threshold device in conjunction with our novel adhesive gloe device for ACD-CPR does not result in additional chest decompression. Resuscitation. 2013; 84:1433-1438.

12) Plaisance P, Lurie K, Payen D. Inspiratory Impedance During Active Compression-Decompression Cardiopulmonary Resuscitation: A Randomized Evaluation in Patients in Cardiac Arrest. Circulation. 2000; 101;989-994.

13) Plaisance P, Lurie K, Vicaut E et al. Evaluation of an impedance threshold device in patients receiving active compression-decompression cardiopulmonary resuscitation for out of hospital cardiac arrest. Resuscitation. 2004; 61:265-271.

14) Wolcke B, Mauer D, Schoefmann M et al. Comparison of Standard Cardiopulmonary Resuscitation Versus the Combination of Active Compression-Decompression Cardiopulmonary Resuscitation and an Inspiratory Impedance Threshold Device for Out-of-Hospital Cardiac Arrest. Circulation. 2003; 108;2201-2205.

15) AHA guidelines 2005

16) Cabrini L, Beccaria P, Landoni G et al. Impact of impedance threshold devices on cardiopulmonary resuscitation: A systematic review and meta-analysis of randomized controlled studies. Crit Care Med. 2008; 35(5);1625-1632. DOI: 10.1097/CCM.0b013e318170ba80.

17) Aufderheide T, Frascone R, Wayne M, et al. Standard cardiopulmonary resuscitation versus active compression-decompression cardiopulmonary resuscitatin with augmentation of negative intrathoracic pressure for out-of-hospital cardiac arrest: a randomized trial. Lancet. 2011; 377:301-311. DOI:10.1016/S01406736(10)62103-4.

18) Aufderheide T, Nichol G, Rea T et al. A Trial of an Impedance Threshold Device in Out-of-Hospital Cardiac Arrest. N Engl J Med 2011; 365:798-806.

19) Biondi G, Abbate A, Landoni G, Zangrillo A, Vincent J, D’Ascenzo F, Frati G. An updated systematic review and meta-analysis on impedance threshold devices in patients undergoing cardiopulmonary resuscitation. Heart, Lung and Vessels. 2014; 6(2): 105-113.

20) AHA 2015 guidelines

21) Yannopolous D, Aufderheide T, Abella B, et al. Quality of CPR: An important effect modifier in cardiac arrest clinical outcomes and intervention effectiveness trials. Resuscitation. 2015; 94:106-113.

22) Wang C, Tsai M, Chang W, et al. Active Compression-Decompression Resuscitation and Impedance Threshold Device for Out-of-Hospital Cardiac Arrest: A Systematic Review and Metaanalysis of Randomized Controlled Trials. Crit Care Med. 2015; 43(4):889-896. DOI: 10.1097/CCM.0000000000000820.

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EMS MEd Blog

The Case

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Patient-centered outcomes

Take Home

1. Brown JB et al. Not all prehospital time is equal: influence of scene time on mortality.J Trauma Acute Care Surg Jul 2016;81(1):93-100.

2. Weaver MD et al. An observational study of shift length, crew familiarity, and occupational injury and illness in emergency medical services workers. Occup Environ Med Nov 2015;72(11):798-804.

4. Drennan IR, Lin S, Sidalak DE, Morrison LJ. Survival rates in out-of-hospital cardiac arrest patients transported without prehospital return of spontaneous circulation: an observational cohort study. Resuscitation. 2014;85(11):1488-93.

Reviewed by Jeremiah Escajeda, MD, @ JerEscajeda

5. Nichol G et al.; ROC Investigators. Trial of continuous or interrupted chest compressions during CPR. N Engl J Med Dec 2015;373(23):2203-14.

6. Fisher R, et al. Police officers can safely and effectively administer intranasal naloxone. Prehosp Emerg Care 2016;20(6):675-80.

8. Prekker ME et al. Pediatric Intubation by paramedics in a large emergency medical services system: process, challenges, and outcomes. Ann Emerg Med Jan 2016;67(1):20-9.

9. Schlapbach LJ et al. High-flow nasal cannula (HFNC) support in interhospital transport of critically ill children Intensive Care Med Apr 2014;40(4):592-9.

10. Clemency BM, Bart JA, Malhotra A, Klun T, Campanella V, Lindstrom H. Patients immobilized with a long spine board rarely have unstable thoracolumbar injuries. Prehosp Emerg Care 2016;20(2):266-72.

12. Scerbo MH, Mumm JP, Gates K, Love JD, Wade CE, Holcomb JB, Cotton BA. Safety and Appropriateness of Tourniquets in 105 Civilians. Prehosp Emerg Care. 2016 Nov-Dec;20(6):712-722.

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**12. Scerbo MH, Mumm JP, Gates K, Love JD, Wade CE, Holcomb JB, Cotton BA. Safety and Appropriateness of Tourniquets in 105 Civilians. Prehosp Emerg Care. 2016 Nov-Dec;20(6):712-722.**