EMS MEd Blog

Discussion Forum: Are We Ready to Incorporate the OMI Paradigm into EMS Destination Decision and Prenotification?

At midnight, an EMS crew responds to a 911 call for chest pain.

The patient is a 40 yo male who developed chest pain while lifting weights 45 minutes ago.  His wife called 911 when he was having trouble sleeping secondary to the pain.  He appears diaphoretic and unwell.

EMS obtains the following ECG :

 

They administer aspirin and begin transport to the hospital.   The paramedic is concerned for an acute myocardial infarction as the patient appear unwell, and they recognize hyperacute inferior T waves and ST depression and T wave inversion in aVL.  

 Should they bypass the closest hospital to transport to the PCI center?  Should they activate an MI alert prior to hospital arrival?

In 2018, the Emergency Medicine community was introduced to the concept of Occlusion Myocardial Infarction when Meyers, Weingart and Smith self-published the OMI Manifesto

 The big idea?  ST elevation on the ECG is an unreliable tool for detecting patients in whom emergent reperfusion therapy is indicated – namely, those with an acute occlusion of a coronary artery. 

Subsequently, Myers et. al. published a retrospective chart review which lent some evidence to the ideas put forth in the OMI manifesto:  38% of patients with an acute occlusion of a coronary artery did not meet STEMI criteria.  The result?  A significant delay to reperfusion therapy.   


 

Given these results, should EMS begin to shift a focus from “STEMI systems of care” to “OMI systems of care”?  Why or why not? 

 

Please share your thoughts and commentary below by December 20th to be included in the summary post. 

Should the EMT scope of practice include supraglottic airway placement? A Discussion Forum Summary.

In February, we posted the following Discussion Forum stem:

 

EMT_scope_National.jpg

EMS is dispatched to a cardiac arrest at a residence with bystander CPR in progress.

 The paramedic and EMT partners arrive on scene to find BLS care being initiated by a company of four firefighters who are credentialed at either the EMR or EMT level.

The paramedic focuses on coordinating the resuscitation including ensuring the priorities of early defibrillation and high-quality CPR, as well as accomplishing the ALS tasks of obtaining IV/IO access and medication administration. While focusing on these priorities, the paramedic would like to off-load airway management to another on-scene provider so a supraglottic airway can be placed.

Supraglottic airway placement is not currently in the 2019 National Scope of Practice Model at the EMT level. However, some states, or where permissible EMS agencies, have placed this within the EMT scope.  Based on survey data collected via the Discussion Forum post, and when possible, confirmed on the state website, the current map of supraglottic airway at the EMT scope of practice is below:

Figure 1: Scope of practice information collected by Discussion forum survey and confirmed by review of the state website when possible.   Image credit: Maia Dorsett

Figure 1: Scope of practice information collected by Discussion forum survey and confirmed by review of the state website when possible. Image credit: Maia Dorsett

There was substantial discussion regarding whether supraglottic airways should be at the EMT scope of practice.   This discussion focused predominantly on three themes:  (1) Advantages and ease of the skill, (2) need for capnography for airway confirmation and (3) the need for additional education and training commensurate with the complexity of not just the skill, but its indications and monitoring.


 Advantages and Ease of skill

A number of comments addressed the relative ease of supraglottic airway  placement as a psychomotor skill.  Review of the evidence suggests that supraglottic airways – including laryngeal tubes and LMAs such as the iGel – have high first pass success rates, even in the hands of novices.   Studies that focus specifically on SGA placement by BLS providers specifically confirm first pass success rates of > 80% and overall success rates of > 90% for the King-LT.[1,2]. One argument is that, at least in cardiac arrest, where SGA as a primary method of airway management has become more common,  offloading this skill to EMTs allows ALS providers to focus on the overall the resuscitation.  In addition, in rural areas with limited access to ALS providers, this gives BLS providers another airway management tool.

 

In South Carolina, SGA insertion is an EMT level skill. For my service and many others in the state that utilize a tiered response model it is used regularly by crews at the EMT level. The requirement for SGA placement is to have a device capable of monitoring capnography/capometry immediately available following device placement. For my service we do not utilize intubation as a first line airway device in cardiac arrest and since the practice was implemented 12 years ago along with some other changes we have seen a drastic increase in return of spontaneous circulation among cardiac arrest patients encountered. There is no reason SGA placement should not be an EMT level skill. – Austin Pace


EMTs are extremely capable of placing supraglottic airways. We have EMT level fire departments who often place these airways early on in the setting of cardiac arrest. With excellent training our EMTs have high success rates. Paramedics are not as plentiful in North Carolina and there are even fewer advanced EMTs in our State. We are teaching supraglottic airways in our initial EMT programs and we feel strongly that this should be part of the National Scope of practice for EMTs - Kim Woodward


With our paramedics doing so much else EMTs need to be able to fully manage airway. – Andie

 

“I believe …this would be allowed everywhere. They are easy to use and offer a way to secure the airway and get oxygen to the patient. I work in Michigan where this is allowed at the EMR level with IGels and colormetric.”- George F

 

Agree, we just added this to their skills with extra training. Especially in Idaho, my agency is very rural and only 2 man crew (1 paramedic and 1EMTB) rare fire back up. We have seen improved codes because of this.- Eric S Donahue

 

SGA and EtCO2 are both within the EMT scope of practice in both my current state of practice (New Hampshire) and my previous (Michigan). EtCO2 hasn't been available on most BLS rigs in my experience (except colorimetric detectors, I guess, which don't offer a lot but better than nothing), but it's something I was trained on by my service and used on ALS shifts. I absolutely used both King airways and i-gels as an EMT-B, and it's something I consider to be crucial for good patient care in the emergent setting. EMTs need to be able to manage airway without a babysitter, and if anything need more training on EtCO2 in the classroom setting.  - Charlotte P

 

I allow in my services and we have incredibly high success rates with our supraglottic (we use igel, no financial relationship) device. Over 90% first pass success with EMT placement almost exclusively in cardiac arrest and 1/2 of our prehospital cardiac arrest airways are secured by EMT versus paramedic. we run around 400 cardiac arrests/year. -  Ryan Jacobsen

 

Use of SGA is a permitted process in WA State. Our current data, using igel, is 80% success by BLS.- Marvin Wayne

 

I think that this is a "trainable" and valuable skill for EMT-B's, and the scope of practice should reflect this. -  Ray Fowler

 

Both of these skills should be available to EMTs. We allow them to use a ventilator (BVM) but not isolate the pulmonary system thereby risking gastric insufflation and aspiration. Allowing the EMT to place a supraglottic device will also allow them to place a gastric decompression tube to improve ventilation. - Jeffrey Siegler

 

In Ohio, the placement of a supraglottic airway is strictly limited to pulseless and apneic patients at the EMT level. If a patient has a pulse, even if apneic, ventilation must be performed by another method, e.g. bag-valve-mask (BVM). For patients with a pulse, even if apneic, there is an increased risk of vomiting and/or aspiration if a supraglottic airway device is in place, compared to a BVM, due to the potential for the return of a gag reflex if the patient responds to assisted ventilation measures. -  Carol Cunningham

 

Yes, This is just as simple as an OPA. - David S. Kugler

  

After three years of work, the State of Alaska is currently implementing its revised Scope of Practice.  This includes SGA for EMT I (Basic) with Medical Director Sponsorship Required. Standing orders are required. Active involvement of the Medical Director in training is crucial. Our EMT II level (similar to Intermediate elsewhere) includes etCO2 monitoring and interpretation and IO, TXA, IV Dextrose.  We have found that we can successfully teach etCO2 at the EMT II level.  After removing ET intubation from this scope (SGA was already there), we found the time in the training to teach these other life-saving skills noted above. This is super important since AEMT and paramedic response are rare outside our larger cities.  So EMT I or II is all you get in most communities.  Dr. Levy and I agree that these skills can help to treat what can kill you now - Tom Quigley Peterson, Co-Chair, SOA Scope of Practice Committee

 

EMTs have always and should always be the masters of basic airway management to include OPA, NPA, BVM ventilation, and now that we have iGel LMAs which are quite easy to train providers to place, should absolutely be within the scope of practice of EMTs. This is especially important in the cardiac / respiratory arrest patient which then allows ALS personnel to focus on ALS interventions. iGels are easier to train EMTs to place than teaching hand ventilation with a BVM – Cstephens

 

Dr. Stephens ends with the discussion that iGels are easier to train than ventilation with a BVM.  Indeed, a number of comments discussed specifically that BVM is actually a difficult - though very important – skill to perform well. 

 

The difficulty of manual ventilation using a BVM is well documented in the literature. The difficulties are threefold;
-Inability to maintain a mask seal
-Inability to control volume
-Inability to control rate
Yet the BVM is a basic or foundational skill for all prehospital levels. Today, supraglottic airways such as the I Gel are simple in sizing, easy to place and help minimize the problem of mask seal. It would seem to me the scope of practice should be amended to add them to the EMT level. It would allow for better focus of volume and rate and hopefully better ventilation. -  Jon Politis

 

 “Less of a practice dependent skill than good BVM management. Allows adequate oxygenation and ventilation.”- Mike Carter

 

BVM ventilation are performed poorly at best from EMR through RT, MD. Without a strong push to bring providers up to "expert" level in there BLS skills SGA's have a place and a need. Without optimally clearing airway on initial contact, properly placing airway adjuncts, properly positioning patient for optimum patency of the airway, proper BVM seal and good ventilation techniques to prevent aspiration, gastric insufflation, barotrauma, or volutrauma. The use of SGA's can increase the margin of error in the above to allow more effective ventilation of the patient and provide some protection of the adverse effects of improper bagging techniques. So yes, I strongly urge WI to continue to support, not only in scope of practice but improved training and education, the ability of EMR's and EMT Basics to place SGA's. - Robert Barrix

 

There are many states that allow it, so expanding the scope is not a big change in much of the country. To me can have a more effective SGA seal for extraction/transport than you can for BVM. Also allows for one less person to focus on the airway (1 for BVM + 1 for bagging versus 1 for bagging with SGA). EtCO2 waveform recognition (not necessarily interpretation) must be part of it in order to verify appropriate placement. Should not lose BVM positioning and seal as a fundamental skill in EMS, though. - Joshua Stilley

 

There is some evidence for these assertions.  In a simulation study of inexperienced providers (senior medical students and first year emergency medicine residents),  inexperienced providers had more difficulty administering adequate tidal volumes with bag mask ventilation versus a laryngeal tube that they placed themselves. [3] In an Austrian study of EMTs (who have ~ 260 hrs of training), successful ventilation by laryngeal tube versus bag valve mask in out-of-hospital cardiac arrest was much higher in the SGA group (92%) versus the BVM group (35%).  [4].  In a subsequent randomized study of 78 patients with OHCA, efficient ventilation by EMTs was also higher (though not significantly) with SGA (71.4%) compared with BVM (58.5%). [5]   These studies defined “success” as the presence of adequate chest rise as assessed by a responding emergency physician  - not End-tidal CO2 .  Capnography use may further demonstrate unrecognized ventilation failure with BVM:

Vithalani_BVM_Failure.001.jpeg

Confirmation of airway

One additional theme of the commentary is the importance of confirmation of effective ventilation with the use of capnography.   Dr. Vithalani published an important article that demonstrated that unrecognized misplacement was a significant issue with SGAs as well, and that end-tidal capnography had a key role to play in monitoring for misplacement and ventilation failure:

Yes - but only if EtCO2 also included and crews adequately equipped. Rate of unrecognized misplacement may be as high as 14% - https://pubmed.ncbi.nlm.nih.gov/28750882/ - Veer Vithalani

His comments regarding the necessity of EtCO2 use were echoed by many others on the thread:

 

If not paramedic on-scene, we require EMT to use calorimetric ETCO2, but ALS required to follow up confirmation with quantitative/waveform capnography. -Ryan Jacobsen

Also, in Ohio, the use of waveform capnography is mandatory when for any invasive airway device, including supraglottic airway devices, are utilized. - Carol Cunningham

 

Tennessee utilizes this, ETCO2 is encouraged but only required at the ALS and CC levels, not at the BLS level. - Tyger Marie

 

Yes, as long as have EtCO2 and training. The use of EtCO2 should also be with BVM - Benjamin Abo

Michigan allows EMTs and EMR to place i-gel supraglottic airways. EMTs can also do King and Combitube but most are adopting i-gel. The decision is based on the agency and oversite organization (Medical Control Authority) choice. Use is not mandatory but is in the state protocols with local options for adoption. Our EMTs and EMRs typically use color change CO2 detection instead of waveform capnography. Agencies that use supraglottic airways must have CO2 detection or waveform capnography. - Robert Domeier

 

In review of state scope of practice, states that allowed for SGA use at the EMT level also allowed for capnography use by EMTs [Figure 1].

 

Training

One commenter, EMT GOOSE, simply wrote “Why on earth WOULDN'T you let an EMT place an SGA?”.

This is well addressed, I think, by the following anonymous comment:

“You're asking the wrong question. The better question is "Should EMT education prepare EMTs to place SGAs?" People are pushing to expand the EMT scope to include more advanced skills, but skills are the easy part. You could teach a monkey to jam a plastic tube into a hole and check for yellow squiggles on the screen.

Skills should be the result of education; they should not be the goal. Technicians learn skills: a cursory overview of who, what, when, where, why, and how to place an SGA can be taught in an afternoon. A clinician, however, is taught the underlying pathophysiology to such a degree that they can recognize the need for an advanced airway before ever learning the skill. If done right, a clinician could intuit at least the general operation of the SGA without being taught, based solely on their understanding of the concepts underlying the device.

Technicians get paid $12 an hour. Clinicians get a sustainable career.

As the saying goes, “Everybody wants to be a bodybuilder, but nobody wants to lift no heavy-*** weights.” “

 

This thought process was echoed by several others:

At some point we do need to differentiate levels of education and scope. The EMT scope can not continue to grow without addressing the actual content and time requirements of education to be eligible for testing at that level. If we continue to water downtime education and give out protocols and skills without education about physiology, pharmacology and disease we are not advancing the profession of EMS with clinicians but rather propagating technicians. - Herbert Schiffer

There was talk about in this protocol roll out, however the Medical Directors Practice Board who write our protocols added CPAP and albuterol to the EMT scope of practice. They decided that the BIAD would be too much to change and educate. In the interim we’re talking about a pilot project to trial Kings for EMT. - Stephen Smith

 

The skill itself is easy but recognizing where the airway went requires more training, education and experience. I agree with comments above about the importance of marrying airway management to EtCO2 monitoring. My system in Maryland sends two paramedics to every arrest so "shedding the airway load" isn't so much of a concern. I think the additional training (initial and on-going) and equipment costs would argue against us expanding the number of clinicians who can perform this skill. However, I could see in smaller systems, where the Medical Director and training staffs have a much tighter span of control, where this could be of use. - Alan Butsch

 

Yes, but only with commensurate increase in training time. As we keep increasing the scope and new skills, we spend less time on the basics to fit it into an already tight schedule. - Jason

 

We continue to add "procedures" to the EMT scope of practice, without increasing the underlying academic base. If we want to adopt the Canada "Primary Care Paramedic" model, let's increase the educational standards accordingly. To much "do" and not enough "know and understand."- Skip Kirkwood

 

Indeed this mirrors the reasoning cited in the National Scope of Practice model regarding additional skills in general:

 “Some States permit licensed EMS personnel to perform skills and roles beyond the minimum skill set as they gain knowledge, additional education, experience, and (possibly) additional certification (See also Section III Specialty Care Delivered by Licensed EMS Personnel.) Care must be taken to consider the level of cognition and critical thinking necessary to perform a skill safely. For instance, some skills may be simple to perform, but require considerable clinical judgment to know when they should, and should not, be performed.”

 The National Scope of Practice Model addresses minimum scope of practice. The average EMT-B program in the United States encompasses somewhere between 120-150 hours of education.   Without increasing total time, everything added is a tradeoff;  to add additional content, we can remove something,  add flexibility at the agency level  or collectively decide that the development and maturation of clinicians is truly the goal at all practice levels, which may not be achievable through this set limit of hours.

Summary

While SGA placement and capnography are not at the national EMT scope of practice, the majority of states have allowed this as an EMT skill either at the state scope of practice or by agency-sponsorship and training.  There is evidence that from a skill-performance perspective, placement success is high and indeed, may be an easier psychomotor skill for inexperienced providers than effective bag valve mask ventilation (which clearly still remains critical).   It is essential that SGA placement and capnography come together, as SGAs still can have placement failure. From the perspective of management of cardiac arrest, the indications are straightforward and may allow ALS clinicians to offload airway management and focus on the resuscitation overall.  However, when considering adding a skill to the scope of practice, we must consider that this requires adding education to an already time-strapped curriculum, which should cover not only how to perform the skill, but when it should (or should not) be performed and how to monitor its effectiveness.

 

Discussion Forum Summary by EMS MEd Editor, Maia Dorsett, MD PhD FAEMS FACEP, @maiadorsett

References:

1.     Bledsoe, B. E., Slattery, D. E., Lauver, R., Forred, W., Johnson, L., & Rigo, G. (2011). Can emergency medical services personnel effectively place and use the Supraglottic Airway Laryngopharyngeal Tube (SALT) airway?. Prehospital Emergency Care15(3), 359-365.

2.     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. Resuscitation82(12), 1525-1528.

3.     Hart, D., Driver, B., Kartha, G., Reardon, R., & Miner, J. (2020). Efficacy of Laryngeal Tube versus Bag Mask Ventilation by Inexperienced Providers. Western Journal of Emergency Medicine21(3), 688.

4.     Roth, D., Hafner, C., Aufmesser, W., Hudabiunigg, K., Wutti, C., Herkner, H., & Schreiber, W. (2015). Safety and feasibility of the laryngeal tube when used by EMTs during out-of-hospital cardiac arrest. The American journal of emergency medicine33(8), 1050-1055.

5.     Fiala, A., Lederer, W., Neumayr, A., Egger, T., Neururer, S., Toferer, E., ... & Paal, P. (2017). EMT-led laryngeal tube vs. face-mask ventilation during cardiopulmonary resuscitation-a multicenter prospective randomized trial. Scandinavian journal of trauma, resuscitation and emergency medicine25(1), 1-7.

 

Should the EMT scope of practice include supraglottic airway placement?

EMS is dispatched to a cardiac arrest at a residence with bystander CPR in progress.

EMT_scope_National.jpg

 The paramedic and EMT partners arrive on scene to find BLS care being initiated by a company of four firefighters who are credentialed at either the EMR or EMT level.

 The paramedic focuses on coordinating the resuscitation including ensuring the priorities of early defibrillation and high-quality CPR, as well as accomplishing the ALS tasks of obtaining IV/IO access and medication administration. While focusing on these priorities, the paramedic would like to off-load airway management to another on-scene provider so a supraglottic airway can be placed.

 Supraglottic airway placement is not currently in the 2019 National Scope of Practice Model at the EMT level. However, some states, or where permissible EMS agencies, have placed this within the EMT scope.

In your service or state, is supraglottic airway placement at the EMT scope?

What are the advantages, disadvantages or concerns regarding this?

 Please leave your comments below by February 28th for them to be included in the discussion forum summary post which will be published next month.  Make sure to include your state of practice in your commentary.

Do push dose pressors have a role in prehospital care?

In November, we posted these cases and discussion stem to the blog discussion forum and got a number of insightful comments regarding the use of push dose vasopressors in the prehospital environment.  This commentary is summarized here.

The term “Push dose pressors” (also known as Bolus-Dose Vasopressors) refers to the intravenous administration of small, discrete doses of vasopressors, such as epinephrine or phenylephrine, to rapidly treat hypotension.[1-2]  The routine use of push dose vasopressors (PDPs) originated in the operating room setting to offset hypotension as a side effect of anesthetic medications, such as hypotension induced by spinal anesthesia. [3-4]  Subsequently their use gained traction in the emergency department and out-of-hospital setting as a result of popularization by the Free Open Access Medical Education (FOAMed) movement. [1, 5, 6]  

 While PDP use has become increasingly common, evidence regarding the benefits and/or harms of their use outside of the operating room remains limited. [1]  As such we asked our readers the following question regarding their EMS system:

-       Are you using push dose vasopressors?  If not, why not? 

-       If so, what are the indications and dosing/frequency? 

-       What is the protocol for their use and what safeguards against medication error are in place?  Are you tracking any quality measures for their use?

 

Yes… BUT

 The Austin-Travis County EMS system uses PDPs as a temporizing measuring pending initiation of vasopressor infusion or to prevent peri-intubation cardiac arrest in a hemodynamically unstable patient in need of invasive airway management… an approach shared by Jeff Jarvis of Williamson County EMS.  

The reason cited for using only as a bridge?  A high risk of medication error. The risk of medication errors in a high stakes, low frequency case is certainly a concern.  What does the current literature say regarding risk of medication errors with PDPs?

Rotando et al. (2018) performed a retrospective analysis of PDP use practice patterns, efficacy and safety in critically ill patients ICU patients at a single institution. [7]  146 patients met their inclusion criteria.  As expected, PDP use improved blood pressure.  However, 17/146 (11.6%) patients had an adverse event associated with push-dose vasopressor use, including dosing errors, administration when patient was not documented to be hypotensive, or administration when patient was already on a continuous infusion vasopressor.

A subsequent retrospective study of Emergency Department PDP use by Cole et al. (2019) also demonstrated a high rate of dosing errors during administration of PDPs. [8] One of the most interesting aspects of this study was that instead of only using standardized chart review, the authors reviewed video of the resuscitations to obtain the majority of their data.  They retrospectively identified 249 patients who received PDPs in the ED between 2010-2017 and then reviewed videos of the resuscitation when available (68% of all cases) for dosing errors, hemodynamic consequences of administration and documentation errors.  They found that adverse hemodynamic events (defined as HR > 140, new bradycardia (HR < 60), SBP > 180, or development of ventricular tachycardia) occurred in 39% of all cases (27% in the phenylephrine group and 50% of the epinephrine group).  Human errors occurred in the care of 19% of patients, including administering a dose different than the intended dose (3%).  Dosing errors included anywhere from 10-fold overdoses of phenylephrine or epinephrine to a 100-fold dosing error of phenylephrine.  The risk of medication error was significantly increased when an ED pharmacist was not present. Of note, the average time for patients to be started on an epinephrine drip was 8 min, whether or not an ED pharmacist was present, leading the authors to making a conclusion very similar to that of @ATCEMS/Jason Pickett:

In select patients with shock whose physiology cannot tolerate the several minutes required to prepare a vasopressor infusion, the improvement of blood pressure and vital organ perfusion imparted by push dose pressors may outweigh potential adverse effects. However, push dose pressors could be deleterious to patients whose outcomes are not likely to be improved with this stop-gap therapy (e.g., those with hypotension who will rapidly correct with no intervention or fluid resuscitation, or those with hypotension but not shock). An important area of future research will be determining the patient population most likely to benefit from this therapy.”

What about risk of error in EMS-based studies of PDP use?

Nawrocki et al. (2019) characterized hemodynamic effects and adverse events associated with push dose epinephrine use during critical care aeromedical transport.[9]  They retrospectively studied patients who received at least one dose of push dose epinephrine to correct documented hypotension (SBP < 90 mmHg or MAP < 65) following the introduction of a protocol directing administration of 10-20 mcg of push dose epinephrine every 2 minutes until vitals normalize or the vasopressor infusion is ready to start. In this study, they found that of the 100 doses of push dose epinephrine administered over a two year period, 94% were deemed “appropriate” in terms of dosing and indication.

Patrick et al. (2020) evaluated the use of push dose epinephrine in ground-based EMS transport. [10]   They performed a one year retrospective chart review of all patient care records where a patient was treated for hypotension (defined as SBP < 90 mmHg) with push dose epinephrine following a protocol very similar to that of Nawrocki et al. They specifically excluded patients whose initial presentation was cardiac arrest.  There was one documented medication error amongst 43 cases (2.3%), which was related to a change in the epinephrine stock concentration from 1:10,000 concentration to 1:1,000 concentration secondary to drug shortages.

Of note, in neither of the above EMS studies was the primary objective to evaluate the incidence of medication error.

Is a Bridge Really Necessary?

The most common cited indication for the PDPs is as a bridge to vasopressor initiation.  In the Cole et al. study, the average time was 8 min and neither of the prehospital studies were set up to measure this interval.  It is thus worth considering whether there is, in general, a different time to initiation a vasopressor initiation in the field versus in the ED.   

Some of the commentary addressed this very issue:

 The benefit for PDP is iatrogenic hypotension from a procedure (RSI) or you walk in and the patient is peri arrest… Appropriate check lists and references after training can help avoid medication errors if pre made medication syringes aren't available. Depending on crew configuration you may not be saving significant time mixing up a stick of pressor vs a bag.

-Shane O'Donnell

We do not currently utilize push dose pressors in the University of Missouri system. We have a pretty aggressive protocol for initiating pressor infusions, including getting one setup for all post-ROSC patients. I have not seen patients decompensate to cardiac arrest without PDP, and to me a couple minutes of hypotension while getting a pressor infusion set up is reasonable and much safer. We also have a strong push for delaying intubation in unstable patients, and my EMS Clinicians have done a good job of embracing that. – Joshua Stilley

Interestingly, in the prehospital study of PDP use by ground EMS [10], almost one half of the administrations were treated with PDPs pre-delayed sequence intubation, most only required 1-2 doses as they received adjunctive treatments such as fluid administration, and only 48% required continuous vasopressor infusion.

 

Countin’ Drips

When considering the risk of dosing error in infusions versus PDPs, there remains one key distinction between hospital and most prehospital systems: the availability of IV pumps.  This complexity was captured in the following comments by Joshua Borkosky, Jeff Jarvis and Ryan Jacobsen:

We do not use Push-Dose pressors in my EMS System currently. We do use (and I personally use) in the academic ED I practice in however. I've seen no convincing evidence in the literature other than the popular gurus (ex. Weingart) espousing their amazingness. In theory I like it, but several caveats. We use norepinephrine drips currently if pressor needed. We don't have pumps however and use a metronome (checklist) to calibrate a rate. It is very imperfect and not awesome. Balancing the risk/benefit of norepinephrine drip without a pump versus mixing a syringe of epinephrine to 10mcg/ml in high risk/low frequency environment is challenging. I have recently found we can get pre-mixed push dose epinephrine (2 month shelf life) so mixing would not be a concern, but likelihood of use versus constantly rotating stock every 2 months in large service has logistics/cost issues. I like the concept in theory. If you have a phenylephrine AND epinephrine premade syringe for push dose you could avoid all need for "drips/pumps" in the 911 urban/suburban environment. I have mixed feelings. - Ryan Jacobsen MD, Medical Director, Johnson County EMS System, Johnson County, KS

Before we jump to suggesting a cheaper “dial-a-drip” or “dial-a-flow” set up, a 2018 study by Loner et al. tested these devices and found them to be inaccurate and associated with both underdosing and overdosing errors. [11]

Given the concern over accuracy of off-pump IV infusions, some EMS systems, particularly urban/suburban transport systems with shorter transport times, opt for PDPs in place of vasopressor infusions given lack of availability of IV pumps.  Given the short prehospital transport times, the prehospital PDP may act as a bridge to the in-hospital infusion in these scenarios:

We use PDPs in LA County. We don’t have pumps, and maybe we should, but most of our transports are less than 15 minutes and PDPs are far simpler to do. We use cardiac Epi diluted 10X (10mcg/mL), 1mL Q 3-5 mins. I just can’t reconcile counting drops/min in the 21st century with all of the tech that we bring to the patient these days. – Clayton Kazan

My system is doing both PDPs and IV drip. I personally stick to PDPs though since we do not have IV pumps. We only have dial a flow devices which are inaccurate at best. I personally feel PDPs are safer because you know exactly how much you are giving because you are in control. I mix 1mg Epi in 500ml NS and give 10-20mcg pushes. - Matt King

 

So, what about that most important quality measure – patient outcome?

So far, all the research we have discussed has evaluated the effect of push dose pressors on hemodynamic parameters, which theoretically serve as surrogate markers for improved outcome because of the known association between hypotension and adverse outcomes, especially for cardiac arrest and traumatic brain injury.

But what if we examined actual patient outcomes?

So far, data is limited to retrospective studies alone.

Guyette et al. (2019) examined the relationship between push dose epinephrine and mortality in patients cared for by aeromedical critical care transport service.  They performed a retrospective case-cohort study that included patients > 14 years of age with SBP < 70 mmHg.  In 2015, the service introduced a protocol for administration of 100 mcg of IV epinephrine (a dose ~ 5-10 times higher than typical PDP dose) to patients with preserved pulses and SBP < 70 mmHg.  This was to be accompanied by volume resuscitation followed by norepinephrine infusion. Each patient who received push dose epinephrine was matched to two historical controls using demographic and prognostic data including age, gender, shock type, weight, index vital signs at first hypotensive episode, and pretreatment characteristics including CPR, defibrillation, transcutaneous pacing, needle thoracostomy, vasopressor administration, intubation or arrhythmia.  Interestingly, 30-day survival was lower in patients who received push dose epinephrine (36% vs. 56%) and was significantly different in an adjusted analysis (p=0.01).  However, given the retrospective nature of the study, it remains possible that the patients receiving PDPs were still sicker despite attempts to control for likely confounders.

Summary & Take Home

There is variability in prehospital PDP use in EMS practice.  While PDPs may have benefit to rapidly address iatrogenic hypotension from a procedure or as a bridge to vasopressor infusion (initiated prehospital or at the hospital destination in the case of short transport times), there are concerns in terms of medication safety and lack of demonstrated benefit in terms of patient outcomes.  This remains an area in need of high-quality prehospital research to inform best practice.

Summary post by Maia Dorsett, MD PhD (@maiadorsett)

Edited by Brian Miller, MD (@BrianMillerMD)

References:

[1] Holden, D., Ramich, J., Timm, E., Pauze, D., & Lesar, T. (2018). Safety considerations and guideline-based safe use recommendations for “bolus-dose” vasopressors in the emergency department. Annals of Emergency Medicine71(1), 83-92.

[2] Cole, J. B. (2017). Bolus-Dose vasopressors in the emergency department: first, do no harm; second, more evidence is needed. Ann Emerg Med1, 3.

[3] Siddik-Sayyid SM, Taha SK, Kanazi GE, et al. (2014).  A randomized controlled trial of variable rate phenylephrine infusion with rescue phenylephrine boluses versus rescue boluses alone on physician interventions during spinal anesthesia for elective cesarean delivery. Anesth Analg. 118:611-618.

[ 4] Doherty A, Ohashi Y, Downey K, et al. (2012). Phenylephrine infusion versus bolus regimens during cesarean delivery under spinal anesthesia: a double-blind randomized clinical trial to assess hemodynamic changes. Anesth Analg. 115:1343-13501

[5] Weingart S. https://emcrit.org/emcrit/bolus-dose-pressors/

[6] Weingart, S. (2015). Push-dose pressors for immediate blood pressure control. Clinical and experimental emergency medicine2(2), 131.

[7] Rotando, A., Picard, L., Delibert, S., Chase, K., Jones, C. M., & Acquisto, N. M. (2019). Push dose pressors: Experience in critically ill patients outside of the operating room. The American journal of emergency medicine37(3), 494-498.

[8] Cole, J. B., Knack, S. K., Karl, E. R., Horton, G. B., Satpathy, R., & Driver, B. E. (2019). Human Errors and Adverse Hemodynamic Events Related to “Push Dose Pressors” in the Emergency Department. Journal of Medical Toxicology15(4), 276-286.

[9] Nawrocki, P. S., Poremba, M., & Lawner, B. J. (2019). Push dose epinephrine use in the management of hypotension during critical care transport. Prehospital Emergency Care.

[10] Patrick, C., Ward, B., Anderson, J., Fioretti, J., Keene, K. R., Oubre, C., ... & Dickson, R. (2020). Prehospital Efficacy and Adverse Events Associated with Bolus Dose Epinephrine in Hypotensive Patients During Ground-Based EMS Transport. Prehospital and Disaster Medicine35(5), 495-500.

[11] Loner, C., Acquisto, N. M., Lenhardt, H., Sensenbach, B., Purick, J., Jones, C. M., & Cushman, J. T. (2018). Accuracy of intravenous infusion flow regulators in the prehospital environment. Prehospital Emergency Care22(5), 645-649.

[12] Guyette, F. X., Martin-Gill, C., Galli, G., McQuaid, N., & Elmer, J. (2019). Bolus dose epinephrine improves blood pressure but is associated with increased mortality in critical care transport. Prehospital Emergency Care23(6), 764-771.

Discussion Forum: A pressor in a push…

Consider Three Clinical scenarios:

Scenario A:

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EMS responds to the scene of a cardiac arrest.  Patient is found in PEA and ROSC is achieved after 5 cycles of CPR.  Immediately Post-ROSC and 3 minutes since the last dose of epinephrine, blood pressure is 110/80, HR 125, EtCO2 45 mmHg, SpO2 of 95%.  Post-ROSC EKG shows an inferior MI.  As the patient is being packaged for transport, a repeat blood pressure of 70/30 is obtained, HR is now 90, and EtCO2 has declined to 30 mmHg.  The paramedic considers starting an epinephrine or norepinephrine drip, but thinks that utilization of push dose pressors may suffice and make it easier to rapidly extricate patient and begin transport towards the local STEMI receiving center… 


Scenario B:

EMS responds to an assisted living facility for altered mental status in a 78 year-old male.  The patient has been becoming progressively more altered over the course of the day and the nursing home reports a fever.  The patient is obtunded and responds only to painful stimuli.  An indwelling Foley catheter is noted to be draining cloudy urine.  VS obtained show a BP 68/30, HR 110, SpO2 89% on room air, RR 24, EtCO2 22 mmHg.  IV access x 2 is obtained on scene, and fluids and oxygen administration are initiated.  The paramedic considers whether push dose pressors may be indicated for this patient… 

Scenario C:

EMS responds to a motor vehicle collision.  The patient has suffered major blunt trauma to the head and pelvis.  Assisted ventilations are initiated, the patient is placed in spinal motion restriction, and a pelvic binder is applied.  Transport is initiated to the nearest trauma center which is 15 minutes away.  VS are BP 80/60, HR 120, RR 12 (assisted), SpO2 96%, EtCO2 30 mmHg.  IV access is initiated and the paramedic considers push dose pressors to support the blood pressure in anticipation of need for airway management en route or in the ED…

Push dose pressor use has become increasingly common in emergency departments and has been introduced to several EMS systems, however the evidence regarding the benefits and/or harms of their use outside of the operating room remains limited.  

We are interested in what your current EMS system is doing and why?  Are you using push dose vasopressors?  If not, why not?  If so, what are the indications and dosing/frequency?  What is the protocol for their use and what safeguards against medication error are in place?  Are you tracking any quality measures for their use?

Please share your comments below by NOVEMBER 20th to be included in the subsequent summary post.

Collateral Damage: COVID-19 and the EMS Psyche

by Jeremiah Escajeda, MD FAEMS

Our world has changed and, according to public health experts in the US, it will never be the same.

EMS continues to staff the front lines of our new reality. 

As local, national and international COVID-19 epidemiological data transforms daily, so do our local EMS protocols, policies and processes, compounding the stress that EMS professionals and first responders endure. We are in “disaster mode” as a speciality. The current pandemic has disrupted everything; our mental edge going to-and-after work, how we interact with patients and colleagues, our friends and our family. 

Some of our geographical regions are fortunate enough to not suffer the severe burden of the overwhelming influx of COVID-19 patients to our healthcare systems as hot spots in New York City already have. We have, however, changed as an international speciality, forever, because of the pandemic. The situation will continue to evolve, but the future holds many uncertainties. 

The COVID-19 pandemic presents additional challenges in our EMS community. A term we would like to call the Collateral COVID-19 Damage. (#CollateralCovidDamage). On one side, we have the physical and mental health ramifications of responding as frontline workers, on the other, the medical interventions that we deliver to all patients have changed. 

Consider three months ago. You and your partner arrive on-scene, mask-free, to an elderly patient with respiratory failure from a nursing facility who had a past medical history of decompensated heart failure and was discharged from the hospital for heart failure 7 days ago.   She is hypertensive and hypoxic.  What would you have done?  Administer some nitroglycerin and place the patient on non-invasive positive pressure ventilation (NIPPV) without hesitation. 

Now, consider that same patient scenario today. 

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Are you wearing the correct personal protective equipment (PPE)? Did the PPE policy change? Did you remember to check your email for updates today? Does your agency have enough PPE? What if you are practicing in a COVID-19 hotspot? What if now your agency doesn’t allow NIPPV because of the aerosolization risk of novel coronavirus-19? What do you do with the “Do Not Intubate” status of this patient? What if this nursing facility recently had 15 positive COVID-19 cases? Should this patient be transported? What do you ask or tell the nursing facility staff members who you know are also scared about their other patients, themselves and their families? What do you tell the patient or the family (although it is likely that they won’t be present because of the COVID-19 visitor restrictions, at the nursing facility, during transport and in the hospital)? Can this patient call family members? Did you write down a phone number for their family? What if the receiving facility does not permit prehospital NIPPV from EMS because of the potential risk to hospital staff? Should you forgo NIPPV altogether, for all patients? You hear wheezing, but albuterol nebulizers are bad right? Your partner confirms this. Did you just touch your face? Do you have enough disinfectant to use at the station? At your house? What if you know that if you transport this patient that they may be intubated, without family present? What if they die alone? What if this was a 40-year-old, because you heard on the news that 40-30-20-year-olds are dying from COVID-19? What is this anti-malaria medicine everyone keeps talking about? What do you do before you go home to disinfect? What do you tell your family? What should you share with them? And what if we could just go back to three months ago?

This is the collateral COVID-19 damage

Having a brain full of these questions is real and it is a normal response to our chaotic, strange world and can be cognitively overwhelming. Just as we can’t go to the grocery store without a mask and a pocket full of sanitizing wipes, we can’t go to a ‘run of the mill’ EMS call without having COVID-19 concerns. This is the new normal for us, for now, but there is hope. 

State-based mitigation strategies are working. Communities, while physically distancing, are socially rallying for all frontline workers. Think about how many “thank yous” or “how are you doings” you have been hearing in recent weeks. The free coffee, food, it all helps to mitigate our own collateral covid-19 damage. What you do is valued and critical to combating this pandemic.   What you do matters. 

We would like to open the post up for you.  Give us an example of how you have found meaning or reaffirmation in your work in these difficult times.  Share a positive experience that you have encountered in the last few weeks as a frontline worker.  Either post here - or if you want - e-mail a sound or video clip, or a written story, to [email protected]

We will combine these into a follow-up post in the coming month. 



Changing Paradigms?  Medication Administration in Cardiac Arrest

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Case Scenario:

EMS is dispatched for a 47 year old male who is unconscious with abnormal breathing.   A double BLS ambulance arrives on scene first. The patient is at first poorly responsive and moaning, but soon after develops agonal respirations and is found to be pulseless. CPR is initiated and an AED is applied.  He is found to be in PEA at the first pulse check. The paramedic arrives 3 minutes later and establishes intravenous access.

What medications, if any, should be given and why?  Are there historical factors or rhythm characteristics that affect this decision? What if the rhythm is ventricular fibrillation?

Within the last few years, a number of studies have challenged the role of medication administration in the treatment of out-of-hospital cardiac arrest.   Have these changed your practice and how?   

Please share your thoughts (ideally with citations!) by January 15th. A summary post will be published in January.

Stroke Destination: An Opportunity for Innovation in System Design

Clinical Scenario:

In June, we posted the following scenario for comment:

EMS is called to the scene of a “possible stroke”.  The patient is a 75 yo female who was last known normal at 8 pm the night before when she went to bed with plans to watch TV before going to sleep.  She fell when she tried to get out of bed at 7 am.  Her daughter lives with her and heard her fall. When she came into the room, she noted that her mother had a right facial droop, right arm and right leg weakness. She also was unable to speak coherently.  The ambulance arrives on scene at 7:30 am and the EMT performs a Cincinnati stroke scale and confirms the findings reported by the patient’s daughter.   

The patient lives 20 minutes away from a community hospital which is designated as a primary stroke center.  The comprehensive stroke center with endovascular capability is located an hour away.

Where should the patient be taken?  What pre-notification alarm bells should be rung?  What criteria should EMS systems use to make these transportation decisions in a way that best serves patients without overburdening both the EMS system and comprehensive stroke centers?

We got many thoughtful comments on the above scenario that highlight the complexity of the systems-of-care decisions that face EMS on a local, regional and national level.

 

Background:  The Changing Landscape of Stroke care

Only incremental changes in stroke treatment occurred after the approval of IV tPA in 1996 which established a 3 hour window for IV thrombolysis.  After publication of the European trial ECASS III in 2008, the window extended to 3-4.5 hours.   But in 2015, a number of clinical trials were published that dramatically increased the management options available for the treatment of stroke patients and challenged the EMS community to change their destination protocols for stroke patients.  These 5 trials, MR. CLEAN, ESCAPE, SWIFT-PRIME, REVASCAT, and EXTEND-IA,  demonstrated that patients with NIHSS > 6 and proven large vessel occlusion by CT-angiogram may benefit from endovascular reperfusion therapy if they present within 6 hrs of stroke onset [1,2,3,4,5].   A subsequent metanalysis (HERMES) concluded that there may be potential benefit out to 7.3 hours after stroke onset [6].

Similarly to trauma centers, stroke centers are not all equivalent:

-        Primary stroke centers (PSCs) provide good stroke care and intravenous tPA

-        Thrombectomy-capable PSC can do everything a PSC does, but also has the capability to perform mechanical thrombectomy

-        Comprehensive Stroke Centers (CSC) have all of the above, plus extensive resources managing the most complicated patients with dedicated Neuro ICU, neurosurgical services, research and educational resources. 

Given the different capabilities of potential destinations, two main issues complicated EMS transport considerations:

(1)   To be eligible for endovascular therapy patients had to have a proven large vessel occlusion on CT angiogram. EMS needed to screen effectively for large vessel occlusions in the field using physical exam.  A number of scales were developed for this purpose, with varying and less than optimal sensitivity and specificity [7-14, Table 1].

(2)   Most of the patients in the above trials received tPA prior to going to endovascular therapy.  In many areas, bypassing a primary stroke center capable of administering tPA in favor of going directly to a comprehensive stroke center would place patients out of the tPA window.

Table 1:&nbsp; Sensitivity and Specificity for Prehospital Screens for Large Vessel Occlusion

Table 1:  Sensitivity and Specificity for Prehospital Screens for Large Vessel Occlusion

Above and beyond this, getting the right patient to the right place at the right time also included considerations for not overburdening Comprehensive stroke centers and excluding primary stroke centers.   Primarily in response to the above, the Mission: Lifeline Stroke was formed and  developed a Severity-Based Stroke Triage Algorithm for EMS to balance the competing demands of time to tPA, access to endovascular capability and overtriage/undertriage to comprehensive stroke centers.

While EMS was still collaboratively identifying best-practices for patients with possible LVO presenting within 6 hrs of last known normal, two other studies were published last summer which again challenged us reexamine our stroke process of care by extending the time window of patients eligible for endovascular treatment. 

The DAWN trial was a prospective, randomized, open-label clinical trial comparing thrombectomy plus standard care vs. standard care [15]. The trial included patients with the following characteristics:

  • Last known well between 6 to 24 hrs
  • NIHSS > 10
  • Imaging-confirmed large vessel occlusion (ICA or proximal MCA)
  • Mismatch between severity of clinical deficit and the infarct volume as determined by perfusion imaging.

The trial found a significant difference in functional independence at 90 days (49% for thrombectomy arm, 13% for standard care, p < 0.001) but no difference in 90 day mortality.

The DEFUSE-3 trial  was a randomized, open-label trial with blinded outcome assessment that compared thrombectomy + medical therapy vs. medical therapy alone [16].  The trial included patients with:

  • Last known well between 6 to 16 hrs
  • NIHSS ≥ 6
  • Imaging-confirmed large vessel occlusion (ICA or proximal MCA)
  • Initial infarct size of < 70 ml
  • Evidence of salvageable ischemic tissue on perfusion imaging defined as ratio of the volume of ischemic tissue on perfusion imaging to infarct volume of ≥1.8

Similarly to the DAWN trial, DEFUSE- found a significant improvement in functional independence at 90 days (endovascular therapy 45%, medical therapy 17%, p < 0.001).

Both trials included patients with severe deficits.  Mean and Inter-quartile range NIHSS for patients receiving thrombectomy in the DAWN and DEFUSE-3 trials were 17 (13-21) and 16 (10-20), respectively   

These trials present several new challenges for EMS transport decisions:

(1)   Patients who are clearly ineligible for IV tPA are included, leading to less competition between transport time to comprehensive stroke center (CSC) and tPA eligibility for a significant proportion of stroke patients.

(2)   The time criteria are broadened and include the very important population of “wake-up” strokes which made up a significant proportion of the LVO stroke population in the above trials. While broadening the population of patients to be screened for eligibility for endovascular therapy, the criteria are actually very narrow and imaging-based, increasing the possibility of a significant amount of over-triage to comprehensive stroke centers. In one retrospective review of all patients with acute ischemic stroke presenting to a Comprehensive Stroke Center only 1.7% of all patients would have qualified for DAWN enrollment with an additional 0.6 – 1.0% meeting DEFUSE-3 criteria. [17]. Moreover, while CT angiogram may be available at many primary stroke centers, the imaging software (like was utilized for patient selection in both DAWN and DEFUSE III) to evaluate perfusion is unlikely to be.

The comments we received on this post presented a number of responses and potential solutions to these challenges.

 

Comment Review:  The Brainstorming Phase and Regional Solutions

The Right Patient

 Dr. Aurora Lybeck made several great comments on this post.  She made the very important point that the first step in patient identification starts with the EMT or paramedic at the patient’s side.  Stating that “we shall use X… “ to screen for LVO without providing appropriate education and feedback to the provider at the patient’s side will decrease the sensitivity, specificity and utility of validated prehospital LVO screens:

 I think there are a few questions to answer before considering if we SHOULD as EMS to screen for LVO strokes and bypass PSCs for CSCs. 1) Can EMS reliably screen for LVO strokes and 2) What benefit is bypassing PSCs and going straight to a CSC going to have to the patient (a small margin of benefit or a large clinically significant benefit) and 3) what is the acceptable over-triage rates at the CSCs?

With regards to training, we can gather some of the evidence that demonstrates that EMTs can successfully perform one of the screening tests (LAPSS, CPSS, LAMS, RACE, or even a full NIHSS), but the implementation of that in a real-life EMS system with not just new training and competency expectations, but also embedded in a new protocol and transport guidelines that can sometimes be confusing depending on geography etc. If you are one medical director and/or educator and have hundreds of EMTs/paramedics, how are you going to adequately train them all? Have them practice the exam? Ensure competency? Scenarios or simulation? It may be possible with a smaller service or one with robust education but in reality, it's an important skill that requires not just skill training but critical thinking and a high degree of clinical competency.” – Aurora Lybeck

 If system-design changes are to succeed, they must include plans for involvement and education of the field provider if they are to effectively improve patient outcomes.

 

 The Right Place at the Right Time

From a system standpoint, the outcome benefit of endovascular therapy for a very select group of patients must be balanced with resource utilization within the system as a whole.  While it is easy to say that every potential LVO should go to a Comprehensive stroke center, this “transport intervention” could come with a significant amount of unnecessary overtriage that may overburden already-overcrowded centers and add significant cost to the system.

Several of the commenters specifically addressed the issue of over-triage to comprehensive stroke centers.  While there was general consensus that embolectomy candidates should be taken to CSC, there was variability in what their path to the stroke center should be.  In some cases, it was felt that prehospital LVO scale was sufficient to warrant PSC bypass.  In others, there was consideration whether the role of the PSC could still play a critical role in the care of these patients by offering a “secondary screen” in which imaging criteria was used to further narrow embolectomy candidates in such a way that significant time was not lost. While in the end this will vary by region structure and resources, these comments highlight the importance of considering different solutions to the same problem, implementing effective system metrics and measuring patient outcomes:

If the patient has signs and symptoms of a large vessel occlusion than bypass the primary stroke center for the comprehensive stroke center because tpa alone at the primary may not be effective against the large clot and clot retrieval will be needed anyway, I think???” – Kyle

 “RACE LAMS or CPSSS positive for LVO need to go to a comprehensive center. These are the prehospitally validated scales for LVO. If it is to far or time intensive call the helicopter. We are happy to help because time is brain and minutes matter.” – Bill K

What criteria should EMS systems use to make these transportation decisions in a way that best serves patients without overburdening both the EMS system and comprehensive stroke centers?
- Patient time since last known to be normal
- Willingness of comprehensive stroke center to be OK with a certain amount of over triage
.” – Greg Friese

RACE LAMS or CPSSS positive for LVO need to go to a comprehensive center. These are the prehospitally validated scales for LVO. If it is to far or time intensive call the helicopter. We are happy to help because time is brain and minutes matter.” – Bill K

We have to be careful when considering this question and come to an answer in a vacuum. EMS triage and destination is critical. But those decisions need to be made in the context of the system of care in region. A regional system of care where the primary stroke center (PSC) can perform a CTA immediately on arrival and upload it to a cloud based imaging viewer that the comprehensive stroke center (CSC) can also immediately review allows the PSC to perform the critical initial function of identifying those that are candidates for embolectomy. Add that to a system where inter-facility transport can be rapidly secured or even auto-launched, the OR can be mobilized ahead of patient arrival, and the patient can be brought directly to the OR at the CSC, and the initial medical contact by EMS to CSC groin puncture time will likely be the same or even less than if the patient was triaged pre-hospital to bypass the PSC and go to the CSC. If too many patients get triaged prehospital to the CSC, then the CSC's resources (personnel, scanners, ED beds, neuro beds) may be overwhelmed and their ability to provide care to their LVO-strokes will be compromised. If there is no LVO or they have an LVO, but aren't a candidate for embolectomy based on the initial imaging acquired, they can be cared for just as well at the PSC as at the CSC in most cases.” - Chris Zammit

Great discussion!
In this patient with wake up stroke I would transport to PSC first. Although she does have a LA Motor Score/CSTAT and RACE concerning for LVO she is a wake up and would need both a primary stroke work up (CT to evaluate for hemorrhage and CTA head and neck to identify if she has LVO lesion) It the CTA is positive then perform CTP or DWMRI to evaluate if she fits the criteria set fourth by the DAWN trial or DEFFUSE 3 for reperfusion. I believe most of this can be done at the PSC if there is a prior algorithm with EMS and cooperation for door in door out transfer direct to intervention to the CSC if she has an LVO and fits criteria.”
– Rob Dickson

So, if we decide that based on the evidence, an EMT can indeed be taught the chosen LVO screening exam and can indeed implement it within a new stroke transport destination protocol and can retain the skill and demonstrate competency over time, now how is that implemented in a given service or area? Some protocols will suggest a given time guidelines (ie if there is a CSC within 30 min, or bypassing a PSC would not extend the patient's ED arrival more than 20 minutes for example). But there is little to no evidence to guide us on how to geographically on transport- not to mention the reality of time estimates that many of us recognize from practicing in the field. If you plop yourself at any given residential address within your service area, do you know exactly how far you are from the closest PSC? CSC? The difference between those sites? Are they supposed to pull up a map with estimated arrival times and calculate the difference? There is so much subjectivity there, it's worth considering all the possible scenarios before implementing a change as important as bypassing a PSC. For some areas, it's a moot point. Where I trained in residency and in fellowship, we were in major metropolitan areas, where a CSC is rarely more than 15-20 minutes away. Unless your PSC is in the complete opposite direction and you're on the edge of the city, there is likely more to gain and less to lose by choosing the CSC over the PSC- as long as that CSC is willing to accept a lot more stroke patients, knowing that EMS may just default to the "easy" decision of bringing all stroke patients to the CSC (not saying it's the right decision, but with complex decision making we know the easiest generalization is often chosen regardless of the protocol minutiae). However, I currently practice in a more rural and suburban area, where the CSC may be over an hour away. For many of our services, it wouldn't make any sense to implement screening and new protocols for LVO occlusion when their closest local facility is a PSC and transporting to the CSC would be a delay long enough to exclude some patients from receiving TPA if they are not interventional candidates- those patients are much better served being brought to the local PSC, treated with TPA if eligible, and transported to the CSC for intervention if indeed an LVO and eligible for endovascular intervention- ie the model we are currently using.” – Aurora Lybeck

 

One other consideration for transport time is patient stability balanced with the clinical skills/training of the field provider:

Where should the patient be taken?
If I am in the story as an EMT ... I am going to the nearest hospital. An hour feels like a long time to be with a patient who potentially needs ALS interventions.”
– Greg Friese

Agree with Greg as well that there are considerations of long transport and risk of airway compromise so provider level of training and capability has to play a role. Also we must consider geographic location and strain on resources from having a truck out of service for 3 hours on this transport.
Lot's depends on geography and capabilities of your particular system
” - Rob Dickson

 

In his expert review of this post, Dr. Pete Panagos (Co-Chair of Mission:Lifeline Stroke) wrote the following:

A big issue also to at least mention is door-in-door-out (DIDO) from PSC to CSC.  IF the decision is to always go to nearest/closest stroke center, then the PSC, and EMS, must be committed to rapid identification, evaluation and transfer out, literally within 30-60 minutes of arrival and/or decision to transfer.

 

Don’t Forget the Basics

 Overall, while I think the prospect of identifying LVOs in the field accurately and transporting them to the most definitive care/CSC is exciting and their expedited treatment and recovery is a clinically important outcome to focus on, I don't want to lose sight of excellent basic stroke care for all patients. For high functioning urban systems with robust education and training that can implement such new screening skills and protocols, maintain competency, and demonstrate success in patient outcomes and acceptable over-triage rates to the CSCs, I think it's great. For most other services though, I think that time in education and emphasis is best spent on excellent basic prehospital stroke care- timely, accurate, checking a glucose and performing a basic Cincinnati stroke scale, appropriate monitoring, sending a stroke alert to the nearest appropriate facility, and bringing the patient straight to CT for the ED team to jump into action. Who knows, maybe someday our more rural services will start identifying LVO strokes and utilizing our HEMS services to get them to a CSC in the future. Thank you to everyone out there putting the time and passion into researching, implementing and closely QA'ing these new clinical changes. Looking forward to the research that will come out of all the systems out there implementing LVO screening by EMS, and certainly hope to see a significant clinical benefit to patients!

For reference and example, here are some Wisconsin LVO protocols currently in use:
-Milwaukee's (using BEFAST): http://county.milwaukee.gov/ImageLibrary/Groups/cntyOEM/EMS/Standards-of-care/Cardio/Stroke2018.pdf
-Madison/Dane County's (using FAST-ED, see page 73): https://em-ems.countyofdane.com/documents/pdf/2018%20DRAFT%20EMS%20Protocols%20-%20DRAFT/DCEMS%20Protocols_%203.9.18%20FINAL%20(web).pdf
-LaCrosse/TriState (using FAST-ED, see page 28): http://www.tristateambulance.org/documents/TSA%20Medical%20Guidelines.pdf
– Aurora Lybeck

 

Last Words

 Why would it be necessary for EMS to make this decision alone? Call stroke alert and report to online medical control” – Mario

Prehospital stroke care does not exist in isolation. The advent of endovascular therapy for stroke challenges the specialty of EMS to  take innovative approaches to system design that incorporate best evidence to improve patient outcomes while balancing the strain on resources.  The best solutions will consider regional factors, focus on field provider education and value comprehensive quality improvement initiatives that acknowledge the critical role of the EMS provider in the stroke care continuum.

 

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

Peer Reviewed by Peter Panagos, MD (@panagos_peter)

References:

 1. Berkhemer, O. A., Fransen, P. S., Beumer, D., Van Den Berg, L. A., Lingsma, H. F., Yoo, A. J., ... & van Walderveen, M. A. (2015). A randomized trial of intraarterial treatment for acute ischemic stroke. New England Journal of Medicine372(1), 11-20.

2. Goyal, M., Demchuk, A. M., Menon, B. K., Eesa, M., Rempel, J. L., Thornton, J., ... & Dowlatshahi, D. (2015). Randomized assessment of rapid endovascular treatment of ischemic stroke. New England Journal of Medicine372(11), 1019-1030.

3. Saver, J. L., Goyal, M., Bonafe, A., Diener, H. C., Levy, E. I., Pereira, V. M., ... & Jansen, O. (2015). Stent-retriever thrombectomy after intravenous t-PA vs. t-PA alone in stroke. New England Journal of Medicine372(24), 2285-2295.

4. Jovin, T. G., Chamorro, A., Cobo, E., de Miquel, M. A., Molina, C. A., Rovira, A., ... & Millán, M. (2015). Thrombectomy within 8 hours after symptom onset in ischemic stroke. New England Journal of Medicine372(24), 2296-2306.

5. Campbell, B. C., Mitchell, P. J., Kleinig, T. J., Dewey, H. M., Churilov, L., Yassi, N., ... & Wu, T. Y. (2015). Endovascular therapy for ischemic stroke with perfusion-imaging selection. New England Journal of Medicine372(11), 1009-1018.

6. Goyal, M., Menon, B. K., Van Zwam, W. H., Dippel, D. W., Mitchell, P. J., Demchuk, A. M., ... & Donnan, G. A. (2016). Endovascular thrombectomy after large-vessel ischaemic stroke: a meta-analysis of individual patient data from five randomised trials. The Lancet387(10029), 1723-1731.

7. Nazliel, B., Starkman, S., Liebeskind, D. S., Ovbiagele, B., Kim, D., Sanossian, N., ... & Duckwiler, G. (2008). A brief prehospital stroke severity scale identifies ischemic stroke patients harboring persisting large arterial occlusions. Stroke39(8), 2264-2267.

8.  de la Ossa, N. P., Carrera, D., Gorchs, M., Querol, M., Millán, M., Gomis, M., ... & Escalada, X. (2014). Design and validation of a prehospital stroke scale to predict large arterial occlusion: the rapid arterial occlusion evaluation scale. Stroke45(1), 87-91.

9.  Katz, B. S., McMullan, J. T., Sucharew, H., Adeoye, O., & Broderick, J. P. (2015). Design and validation of a prehospital scale to predict stroke severity: Cincinnati Prehospital Stroke Severity Scale. Stroke, STROKEAHA-115.

10.  Kummer, B. R., Gialdini, G., Sevush, J. L., Kamel, H., Patsalides, A., & Navi, B. B. (2016). External validation of the cincinnati prehospital stroke severity scale. Journal of Stroke and Cerebrovascular Diseases25(5), 1270-1274.

11.  Lima, F. O., Silva, G. S., Furie, K. L., Frankel, M. R., Lev, M. H., Camargo, É. C., ... & Nogueira, R. G. (2016). Field assessment stroke triage for emergency destination: a simple and accurate prehospital scale to detect large vessel occlusion strokes. Stroke47(8), 1997-2002.

12.  Hastrup, S., Damgaard, D., Johnsen, S. P., & Andersen, G. (2016). Prehospital acute stroke severity scale to predict large artery occlusion: design and comparison with other scales. Stroke, STROKEAHA-115.

13.  Demeestere, J., Garcia-Esperon, C., Lin, L., Bivard, A., Ang, T., Smoll, N. R., ... & Parsons, M. (2017). Validation of the National Institutes of Health stroke scale-8 to detect large vessel occlusion in ischemic stroke. Journal of Stroke and Cerebrovascular Diseases26(7), 1419-1426.

14.  McMullan, J. T., Katz, B., Broderick, J., Schmit, P., Sucharew, H., & Adeoye, O. (2017). Prospective prehospital evaluation of the Cincinnati stroke triage assessment tool. Prehospital Emergency Care21(4), 481-488.

15. Nogueira, R. G., Jadhav, A. P., Haussen, D. C., Bonafe, A., Budzik, R. F., Bhuva, P., ... & Sila, C. A. (2018). Thrombectomy 6 to 24 hours after stroke with a mismatch between deficit and infarct. New England Journal of Medicine378(1), 11-21.

16. Albers, G. W., Marks, M. P., Kemp, S., Christensen, S., Tsai, J. P., Ortega-Gutierrez, S., ... & Sarraj, A. (2018). Thrombectomy for stroke at 6 to 16 hours with selection by perfusion imaging. New England Journal of Medicine378(8), 708-718.

17. Jadhav, A. Desai, S., Kenmuir C, Rocha, M, Starr, M, Molyneaux, B, Gross, B, Jankowitz, B, Jovin, T. (2018).  Eligibility for Endovascular Trial Enrollment in the 6- to24- hour time window: Analysis of a Single Comprehensive Stroke Center. Stroke. 49:00-00.

 

 

The Most Appropriate Destination...

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EMS is called to the scene of a “possible stroke”.  The patient is a 75 yo female who was last known normal at 8 pm the night before when she went to bed with plans to watch TV before going to sleep.  She fell when she tried to get out of bed at 7 am.  Her daughter lives with her and heard her fall. When she came into the room, she noted that her mother had a right facial droop, right arm and right leg weakness. She also was unable to speak coherently.  The ambulance arrives on scene at 7:30 am and the EMT  performs a Cincinnati stroke scale and confirms the findings reported by the patient’s daughter.   

The patient lives 20 minutes away from a community hospital which is designated as a primary stroke center.  The comprehensive stroke center with endovascular capability is located an hour away.

Where should the patient be taken?  What pre-notification alarm bells should be rung?  What criteria should EMS systems use to make these transportation decisions in a way that best serves patients without overburdening both the EMS system and comprehensive stroke centers?

Discussion Forum summary will be posted mid-July.

A Patient by Any Other Name: Approach to the "Lift Assist"

On March 3rd, we published the following case stem:

lift_image.jpg

EMS is dispatched to the home of a 75 yo female for a “lift assist”.  Reportedly, the patient slipped out of bed when getting up in the morning and needs assistance in getting off the floor.  Per dispatch, she is alert and denies other complaints.  This is not the first time EMS has been dispatched to this household for a similar complaint.  Driving to the scene, the EMS crew begins to debate whether a full Patient Care Record should be completed.  

We asked our readers three questions with regard to this scenario:

How do you define a "patient" in EMS?  

What defines a "lift assist" in your system?

What is the minimum assessment that should be performed and/or documented?

 

Our readers responded with a number of thoughtful comments and references.

 

How do you define a "patient" in EMS?  

There was general consensus that the term “patient” should be defined broadly within EMS: 

 “A patient is an individual requesting or potentially needing medical evaluation or treatment. The patient-provider relationship is established by either phone, radio, or personal contact. It is the providers responsibility to insure all potential patients regardless of the size of the incident are offered the opportunity for evaluation, treatment, and/or transport.”  - Eddie, from Wake Co EMS

 Is it safe to say any one an ems professional physically touches is a patient? - Jeremiah Escajeda

 “A patient is any member of the community served by the EMS that has a health problem requiring assessment and management by an EMT.” - Bill Lord

“My definition would be any person who needs or requests care. I have struggled with this question as an EMS Medical Director for over 30 years. My corporate legal counsel and our legal counsel for our state EMS agency gives this opinion: a person becomes a patient when they are contacted by an EMS provider. Period. No questions in their mind. My classic example is a non-injury MVC, called in by a passerby who dutifully calls 911 making the report. When asked if there are any injuries, they say "don't know", and they don't because they drove on. In our system, "don't know" gets a fire/ems/law enforcement response. If the people have no injury, did not request ems service, have a low or non-existent MOI, do not request evaluation or transport, I would think this would be a "no patient contact" response. However, as long as my legal consultants have the opinion that these folks are "patients" we will evaluate them and complete a PCR.”  - Irvin Smith, MD. Mercy Regional EMS. Paducah, Ky

Indeed, in a review of EMS liability cases (albeit from 1987 – 1992), the most common negligence allegations in patient care cases were arrival delay, inadequate assessment, inadequate treatment, patient transport delay and no patient transport. [1]  Legally speaking, proof of negligence does not require intent, but it does require that the EMS provider has a duty to act. [2] While the above definitions of patients are rather broad, they have important differences regarding interpretation of this duty to act.  The definition of patient provided by Bill Lord requires that you have a health problem requiring evaluation, while the Wake County definition considers someone with the potential to need evaluation and treatment a patient as well.  As alluded to by Irvin Smith, this becomes tricky when a third party caller requests assistance on the behalf of someone who does not want it, but it seems reasonable that there is some sort of documentation of this encounter (i.e. a person with decision making capacity refused evaluation and care) in case an accusation of negligence or abandonment were to appear in the future.

 

What defines a "lift assist" in your system and what is the minimum assessment that should be performed and/or documented?

Commenters generally agreed that “lift assist” was a potentially dangerous term because it puts providers in the mindset that the patient is not ill.

Heard this conversation in hospital ems room one day btw two different agency medics: “does your medical director make you get vital signs on your lift assists? Ours does!”

We should also ask what is response level in your EMS system for a “lift assist” call? Does your 911 system use the term “lift assist”

We should stop using that term. Exchange it with “fall.” A simple approach to highlighting a high risk pt population who we know are often elderly (high under triage rate [1]) and have a frequent short term representation rate with the healthcare system for what is often serious pathology[2].

1.Kodadek LM, Selvarajah S, Velopulos CG et al. Undertriage of older trauma patients: is this a national phenomenon? J Surg Research. 2015;199:220-229.
2.https://www.tandfonline.com/doi/abs/10.1080/10903127.2017.1308607.”
- Jeremiah Escajeda

 

There is no such term. Anyone with impaired mobility that requires assistance to mobilize requires an assessment of their health status before deciding that the patient does not require further medical assessment or referral to an agency that can implement a falls assessment and mitigation program with the patient’s consent….We know that a significant number of elderly who experience a fall but are not transported by EMTs have a subsequent fall, often resulting in a catastrophic injury such as a fractured neck of femur. The mortality rate in this cohort is also alarmingly high. http://qualitysafety.bmj.com/content/15/6/390
This reinforces the need for a focused examination in any older person who has fallen, even if they appear uninjured. Assessment should include tests of proprioception, balance and ability to mobilize. This is particularly important where the patient lives independently or has inadequate support. This suggests the need for an experienced clinician trained in this type of clinical assessment. However, there is evidence that paramedics don’t see this as their “core business”. We need to change this perception. See: https://bmchealthservres.biomedcentral.com/articles/10.1186/s12913-017-2243-y
Bill Lord

 

My mentor and EMS fellowship program director, Sabina Braithwaite, describes her approach to the “lift assist” the same way she describes most things: directly and logically.  Per Sabina, “When you need to call 911 to get your ass off the floor, that ain’t normal. You’ve probably got a problem and you deserve to be evaluated.”  Two studies that have examined outcomes of the “lift assist” patient have provided evidence for this clinical approach.  Cone et. al. examined the outcomes of 9-1-1 responses coded as “lift assists” from 2004-2009.  They found that these accounted for a total of 4.8% of all EMS calls and more than half of these had a return visit within 30 days.  On return visits, more than 50% were transported to the hospital. [3] More recently, Leggatt at al. published a retrospective analysis of 14-day morbidity and mortality among patients with an index lift-assist call. They found that out of 414 patients who called for a lift-assist, 21% had an ED visit, 11.6 % had a hospital admission and 1.1% died within 14 days of the index lift assist call.[4] These findings suggest that the index “lift-assist” call could have been an indicator of a functional decline, or alternatively just represent an overall sicker population. [5] While not every “lift assist” patient is a fall (e.g. the patient who needs assistance from the toilet to their bedroom), the vast majority likely fit the criteria for broad definition of patient as described above and deserve a medical assessment.

The commenters also make a more subtle and important point about the role of EMS in caring for these patients.  While few paramedics enter school with the goal of taking care of geriatric fallers, this population makes up a substantial proportion of EMS calls. [6,7]  As EMS providers find themselves spending their time on non-life-threatening work, this fosters  “low acuity fatigue”,  a “misplaced preconception before arriving at the scene that there will be nothing seriously wrong with the patient.” [6] While a substantial proportion of these patients will not require transport and should not be transported [8,9], a number of serious illnesses can lead to patient being on the floor and unable to get up (e.g. hypotension, stroke etc.).  Even in the absence of serious illness, visits to patients’ homes by EMS represent a unique opportunity for intervention for elderly patients who fall. EMS providers are able to assess multiple factors that likely affect long term health of elderly patients, such as the safety of their home environment or what their home environment conveys about their ability to care for themselves at their current level of assistance. [10]   Ideally, in cases of both transported and non-transported patients who fall, EMS can be incorporated into the integrated healthcare network that provides preventative care to this population to both decrease their risk of subsequent fall or their risk of harm from a subsequent fall. [11,12] EMS education will be essential to this process by promoting the perception that the care of the geriatric fall patient is “legitimate work” and an opportunity to do a tremendous amount of good. [6] Indeed, the health of the community and EMS provider job satisfaction stand to gain a lot from such a culture change.

Summary by EMS MEd Editor  Maia Dorsett, MD PhD @maiadorsett

1.     Ogilvie, W. (2017). EMS, Legal and Ethical Issues.

2.     Morgan, D. L., Wainscott, M. P., & Knowles, H. C. (1994). Emergency medical services liability litigation in the United States: 1987 to 1992. Prehospital and disaster medicine9(4), 214-220.

3.     Cone, D. C., Ahern, J., Lee, C. H., Baker, D., Murphy, T., & Bogucki, S. (2013). A descriptive study of the “lift-assist” call. Prehospital Emergency Care17(1), 51-56.

4.     Leggatt, L., Van Aarsen, K., Columbus, M., Dukelow, A., Lewell, M., Davis, M., & McLeod, S. (2017). Morbidity and mortality associated with prehospital “lift-assist” calls. Prehospital Emergency Care21(5), 556-562.

5.     Brown, Lawrence H. "Researching Lift-Assists: Nebulous Complexity." (2017): Prehospital Emergency Care . 670-672.

6.     Simpson, P., Thomas, R., Bendall, J., Lord, B., Lord, S., & Close, J. (2017). ‘Popping nana back into bed’-a qualitative exploration of paramedic decision making when caring for older people who have fallen. BMC health services research17(1), 299.

7.     Evans, C. S., Platts-Mills, T. F., Fernandez, A. R., Grover, J. M., Cabanas, J. G., Patel, M. D., ... & Brice, J. H. (2017). Repeated emergency medical services use by older adults: analysis of a comprehensive statewide database. Annals of emergency medicine.

8.     Williams, J. G., Bachman, M. W., Jones, A. W., Myers, J. B., Kronhaus, A. K., Miller, D. L., ... & Tibbo-Valeriote, H. (2015). Retrospective validation of a protocol to limit unnecessary transport of assisted-living residents who fall. Prehospital Emergency Care19(1), 68-78.

9.     Williams, J. G., Bachman, M. W., Lyons, M. D., Currie, B. B., Brown, L. H., Jones, A. W., ... & Myers, J. B. (2017). Improving decisions about transport to the emergency department for assisted living residents who fall. Annals of internal medicine.

10.  Weiss, S. J., Chong, R., Ong, M., Ernst, A. A., & Balash, M. (2003). Emergency Medical Services Screening of Elderly Falls in the Home. Prehospital Emergency Care7(1), 79-84.

11.  Snooks, H. A., Anthony, R., Chatters, R., Dale, J., Fothergill, R. T., Gaze, S., ... & Lyons, R. A. (2017). Paramedic assessment of older adults after falls, including community care referral pathway: cluster randomized trial. Annals of emergency medicine

12.  Wofford, J. L., Schwartz, E., & Byrum, J. E. (1993). The role of emergency services in health care for the elderly: a review. The Journal of emergency medicine11(3), 317-326.

 

When Vfib is Stubborn...

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On December 5th we posted the following case for discussion and asked our readers to comment on the management of refractory ventricular fibrillation.  Here is the summary of comments received, both on the blog, and via twitter.

The Case….

A 56 year-old male is cleaning out his garage with his wife when she hears him fall.  She turns around to find him unresponsive on the ground.  He is making gasping breath sounds but otherwise does not respond when she shakes him and yells at him.  She is instructed to perform CPR by pre-arrival instructions after calling 911 on her cellphone.  Within minutes, the BLS Fire Department arrives and takes over.  After confirming that the patient is pulseless, they resume CPR while applying an AED.   The AED states “shock advised” for ventricular fibrillation.  After resuming CPR after one shock is delivered, the ALS ambulance arrives.  High performance CPR is continued and the patient is defibrillated three more times for persistent ventricular fibrillation.  The end-tidal CO2 is 40 mmHg.   The patient has now been pulseless for almost twenty minutes.  The paramedics plan on continuing high performance CPR, but wonder what they will do if the patient remains in ventricular fibrillation with a good end-tidal 10 minutes from now…

 

Improvements in the care of patients with out-of-hospital cardiac arrest have changed patient outcomes dramatically.  More uniform collection of out-of-hospital cardiac arrest data  has allowed benchmarking and the identification of high performance CPR as the key ingredient in neurologically intact survival.  We have learned that doing the basics well makes the critical difference.  Cardiac arrest management has undergone a major transition from the ‘load and go’ strategy to high-performance CPR on scene.

However, a small proportion of out-of-hospital cardiac arrest patients may benefit from more than what we typically are able to offer prehospital.  Emerging evidence suggests that patients with refractory ventricular fibrillation(VF) may be one such population.   However, as pointed out by comments made by Dr. Aurora Lybeck, this population remains ill-defined:

 

“One major issue/barrier to researching this in a meaningful way is that there doesn't seem to be a consensus definition of what "refractory" or "persistent" VF/pVT is. Is it 3 shocks? 5? 7? a predefined number of minutes? To date, there doesn't seem to be even a majority agreement as to how we define this.” – Aurora Lybeck

 

One Japanese study defined refractory ventricular fibrillation as presentation to the hospital in ventricular fibrillation after at least one out-of-hospital defibrillation [1].  In this study, refractory VF accounted for 23% of all patients with VF as a presenting rhythm and 4% of witnessed OHCA.   In other studies, refractory VF was VF that was unresponsive to at least 3 defibrillation attempts and administration of 300 mg of IV amiodarone [2], or a median of 6 defibrillation attempts and anti-arrhythmic administration [3].  As discussed over twitter by Tom Bouthillet and John Lyng, “refractory” may be considered persistent VF despite already excellent high-performance CPR and correctly performed defibrillation:

twitter_refractoryVfib.jpg

If at minimum we define refractory VF as VF unresponsive to the best we have to offer with standard high performance prehospital ALS care, what are some of the non-standard interventions that we may be able to offer?

 

“There is an ever- growing body of literature to help us understand at least how to get the patient OUT of VF/VT. We are better understanding therapeutic options, be it pharmaceutical, electric (shameless plug for changing pad vectors, double sequential defibrillation), or some of the more aggressive options such as ECMO, an amazing but obviously not universally feasible option” – Aurora Lybeck

 

Dr. Lybeck starts by mentioning pharmaceutical options and double sequential defibrillation.  Let’s review the evidence regarding these as adjuncts to high performance CPR.

Pharmaceutical options: Recently, a small number of observational studies have been published suggesting that esmolol administration should be considered for patients in refractory ventricular fibrillation.  In a paper published in 2014, Driver et. al. reviewed the cases of 25 patients with OHCA and refractory ventricular fibrillation (no ROSC despite three defibrillation attempts, 300 mg of amiodarone and 3 mg of epinephrine) and arrival in ED with persistent ventricular fibrillation [3].  They compared patients with received esmolol (n=6) to patients who did not (n=19).  Patient’s had a similar proportion of patients with VF as their presenting rhythm and with witnessed arrest. 3/6 (50%) of patients receiving esmolol survived to hospital discharge with good neurologic outcome compared with 2/19 (10.5%) of patients in the no-esmolol group. A subsequent paper published in 2016 by a Korean group (Lee et. al.) was a pre-post study of inclusion of esmolol in a treatment algorithm for refractory VF [4].  Using the same inclusion criteria as the Driver et. al. study, they compared patients who did and did not receive esmolol.  While patients who received esmolol were more likely to get ROSC [9/16 (53%) vs. 4/25 (16%)], there was no statistically significant difference in neurologically-intact survival at 30 days (18.8% in esmolol group vs. 8% in non-esmolol group).  The numbers were overall very small.

Double Sequential Defibrillation: Double Sequential defibrillation (DSD), the use of two sets of pads and defibrillators to deliver two nearly simultaneously shocks at two different vectors, has gained attention as a therapy for refractory ventricular fibrillation.  The majority of examples are case reports [5] or case series [6].  The few retrospective studies that have been published have very small numbers of patients who received the therapy. In Ohio, a retrospective study of 2428 patients with OHCA found that 12 were treated with DSD.  Of these, 9 patients were converted out of VF, with 2 surviving to hospital discharge with a good neurologic outcome (CPC 1 or 2) [7].   A subsequent retrospective review of DSD use in OHCA in London found that of 45 patients treated with DSD in an 18 month period, only 7% survived to hospital discharge.  This rate was comparable to a that in a comparator group that continued to receive standard defibrillation alone [8]. The jury on double sequential defibrillation is still undecided and a randomized control trial does not exist, but it remains something to consider in the case of refractory VF.  

Above and beyond drugs and electricity, Dr. Lybeck mentions another less available but more aggressive intervention – ECMO (aka ECPR).  The goal of ECMO is to restore oxygenation and perfusion while enabling interventions that treat the underlying etiology of the arrest.  In the case of refractory VF, it is worthwhile thinking about etiologies that are not reversible with standard prehospital ALS care.   The most common etiology for refractory Vfib in multiple studies is acute coronary syndrome, anywhere from 42.1% in a French study to 84% in a study in Minnesota [2,8].  Other less common etiologies include aortic dissection and pulmonary embolism [3].  This suggests that what a subset of patients with refractory VF need is coronary reperfusion therapy in order to re-establish a perfusing rhythm. 

ECMO/ Extracorporeal Life Support (ECLS) and coronary reperfusion therapy has been pursued in a number of EMS systems internationally, some with very impressive results.   The CHEER trial was carried out in Melbourne, Australia [10].  They utilized a combination of mechanical CPR, hypothermia, ECMO and early reperfusion for patients with refractory cardiac arrest.  Inclusion criteria included age 18-65 years, cardiac arrest due to suspected cardiac etiology, chest compressions initiated within 10 minutes by bystanders or EMS, an initial rhythm of VF and availability of mechanical CPR.  A total of 11 patients were transported over a 32 month period and 9 received ECLS.  Five of 11 (45%) transported patients survived with good neurologic outcome.  Subsequently, a larger trial has been carried out in the United States (Minnesota).  Using a more protocolized approach, patients with VF/VT as their initial rhythm, age 18-75 yrs and VF refractory to 3 EMS delivered shocks, 300 mg of IV/IO amiodarone, lack of pre-existing severe comorbidities or terminal illness, body habitus to fit within a mechanical CPR device and estimated transfer time from scene to the cardiac catheterization lab < 30 minutes were transported with mechanical CPR in progress. ECLS was initiated in the cardiac catheterization lab and patients underwent cardiac catheterization which identified coronary occlusion in 84%.   62 patients met transport criteria and 55 had ECLS initiated.  Of these, 28 (45%) survived to hospital discharge, 26 of whom (42%) had good neurologic outcome [2].  This was better than outcomes in a historical comparison group (15.3% neuro-intact survival).  These findings are consistent with a prior prospective observational study in Japan comparing outcomes for patients with refractory VF who underwent conventional cardiopulmonary resuscitation versus ECLS [11].   The authors compared neurologically-intact survival for patients transported to tertiary centers that performed ECLS on standard protocol versus those that did not. They found that patients who received ECLS had significantly high neurologically-intact survival (12.3%) than those who did not (1.5%), although these rates were overall lower than those documented in the CHEER and Minnesota trials. This trial was unable to account for differences in baseline care between ECLS and non-ECLS tertiary care centers.

ECLS, however, is a resource-intensive endeavor.  Low threshold for implementation of advanced therapies such as EPCR is not likely to lead to a high value intervention.  Can we identify patients who both require advanced therapies to convert out ventricular fibrillation and are likely to do well?

With the respect to our case, In Princess Bride-like form, Dr. Jeremiah Escajeda stated the following:  “This patient has aliveness. He should be transported …”

1477157576-0.jpg

What features of this patient’s case make it so that he is only “mostly dead”?  Dr. Escajeda goes on to share the criteria in the Pittsburgh area for transport for EPCR:

We have a prehospital alert system in place here in Pittsburgh that when providers identify a refractory organized rhythm, in a "young," healthy person, they speak with a command physician to run our prehospital ECPR checklist. If criteria are met, the patient is then expeditiously transported to our ECPR center with an alert sent to our ECMO team, ED team, Post Cardiac Arrest team and Cardiology. After the patient is placed on the circuit, next destination is cath lab.

Here is the prehospital checklist:
* Strongly suggested to place patient on LUCAS Device as soon as available
* Call attending medic command physician to run checklist

[ ] Witnessed arrest
[ ] Bystander CPR
[ ] Age ≥ 18 and ≤60
[ ] Initial shockable rhythm or PEA rate > 20 bpm
[ ] Good functional status prior to arrest (patient living independently and not from a skilled nursing facility/ LTAC and no prior neurocognitive dysfunction)
[ ] No signs of irreversible organ dysfunction (such as COPD on home O2, stigmata of liver cirrhosis or ESRD such as AV fistula or terminal cancer)
[ ] No morbid obesity (Morbid obesity defined as inability to fit into LUCAS device and/or abdominal pannus overhanging inguinal crease)
[ ] End tidal CO2 >10 mmHg with CPR
[ ] Expected time from collapse to ED arrival <= 30 mins

Hey maybe even one day we will be placing ECLS devices prehospital, has this has already been done in France https://www.ncbi.nlm.nih.gov/pubmed/28414164
and now they have impella devices that deliver 5L/min, and are the size of a pencil. Exciting future for these refractory cases
.”

Image Source/Reference:&nbsp;Reynolds, J. C., Grunau, B. E., Elmer, J., Rittenberger, J. C., Sawyer, K. N., Kurz, M. C., ... &amp; Callaway, C. W. (2017). Prevalence, natural history, and time-dependent outcomes of a multi-center North American coho…

Image Source/Reference: Reynolds, J. C., Grunau, B. E., Elmer, J., Rittenberger, J. C., Sawyer, K. N., Kurz, M. C., ... & Callaway, C. W. (2017). Prevalence, natural history, and time-dependent outcomes of a multi-center North American cohort of out-of-hospital cardiac arrest extracorporeal CPR candidates. Resuscitation.

This prehospital checklist accounts for factors that we already know are associated with favorable neurologically-intact survival from OHCA.  But a critical question (and perhaps gets back to the question of the term “refractory”) is at what time interval should we start thinking about transporting the patient? How can we identify patients who have received the maximum potential benefit of on-scene care while still retaining benefit from care escalation in the form of ECLS?  Many patients will achieve ROSC without EPCR and initiating EPCR too early may distract from continuous, high-quality chest compressions.  The Pittsburgh protocol of time of collapse to ED arrival of < 30 minutes has evidence behind it.  A retrospective study of patients with OHCA within the ROC consortium examined the probability of good neurologic outcome in patients who would be considered eligible for EPCR (met age and pre-cardiac arrest functional status data) versus duration of resuscitation [12]. They found that amongst all eligible patients, the probability of neurologically-intact survival dropped below 10% after 30 minutes of resuscitation (see Figure).  They thus concluded that mobilization towards EPCR resources should be considered after 9-20 minutes of active resuscitation. Interestingly, amongst patients who achieved ROSC, longer durations of CPR were no longer associated with impaired neurologic outcomes (See Figure).  The results of this study concurred with a prior study of consecutive patients age < 65 with witnessed arrest and initiation of CPR in < 10 minutes that concluded that “transport for ECPR should be considered between 8 to 24 minutes of professional on-scene resuscitation, with 16 minutes balancing the risks and benefits of early and later transport. Earlier transport within this window may be preferred if high quality CPR can be maintained during transport and for those with initial non-shockable rhythms.” [13]

Conclusion

In the end, every EMS system has a limited amount of time and resources for training.  The healthcare system itself is resource-limited.  After years of focus on “Airway” before “Circulation”, we have come to the understanding that we need to focus on circulation; excellent BLS care in the form of high quality CPR and early defibrillation is the cornerstone of cardiac arrest care.  However, there are a subset of patients with potential for neurologically-intact survival that may be saved by additional circulatory intervention, including extracorporeal support and coronary reperfusion therapy.  Identifying who these patients are and the best way to both provide this therapy while utilizing limited healthcare resources in a high value manner may be the future of cardiac arrest care. 

Dr. Lybeck said it best, so we’ll end with her quote:

Particularly on the topic of OHCA, it's an exciting time to be an EMS physician, many thanks to our researchers, educators, and advocates out there, keep up the great work!”

Case Summary by  Maia Dorsett,  MD PhD, @maiadorsett

References:

1.     Sakai, T., Iwami, T., Tasaki, O., Kawamura, T., Hayashi, Y., Rinka, H., ... & Kajino, K. (2010). Incidence and outcomes of out-of-hospital cardiac arrest with shock-resistant ventricular fibrillation: data from a large population-based cohort. Resuscitation81(8), 956-961.

2.     Yannopoulos, D., Bartos, J. A., Raveendran, G., Conterato, M., Frascone, R. J., Trembley, A., ... & Wilson, R. F. (2017). Coronary artery disease in patients with out-of-Hospital refractory ventricular fibrillation cardiac arrest. Journal of the American College of Cardiology70(9), 1109-1117.

3.     Driver, B. E., Debaty, G., Plummer, D. W., & Smith, S. W. (2014). Use of esmolol after failure of standard cardiopulmonary resuscitation to treat patients with refractory ventricular fibrillation. Resuscitation85(10), 1337-1341.

4.     Lee, Y. H., Lee, K. J., Min, Y. H., Ahn, H. C., Sohn, Y. D., Lee, W. W., ... & Park, S. O. (2016). Refractory ventricular fibrillation treated with esmolol. Resuscitation107, 150-155.

5.     Lybeck, A. M., Moy, H. P., & Tan, D. K. (2015). Double sequential defibrillation for refractory ventricular fibrillation: a case report. Prehospital emergency care19(4), 554-557.

6.     Cabañas, J. G., Myers, J. B., Williams, J. G., De Maio, V. J., & Bachman, M. W. (2015). Double sequential external defibrillation in out-of-hospital refractory ventricular fibrillation: a report of ten cases. Prehospital emergency care19(1), 126-130.

7.     Cortez, E., Krebs, W., Davis, J., Keseg, D. P., & Panchal, A. R. (2016). Use of double sequential external defibrillation for refractory ventricular fibrillation during out-of-hospital cardiac arrest. Resuscitation108, 82-86.

8.     Emmerson, A. C., Whitbread, M., & Fothergill, R. T. (2017). Double sequential defibrillation therapy for out-of-hospital cardiac arrests: the London experience. Resuscitation.

9.     Pozzi, M., Koffel, C., Armoiry, X., Pavlakovic, I., Neidecker, J., Prieur, C., ... & Obadia, J. F. (2016). Extracorporeal life support for refractory out-of-hospital cardiac arrest: should we still fight for? A single-centre, 5-year experience. International journal of cardiology204, 70-76.

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). Resuscitation86, 88-94.

11.  Sakamoto, T., Morimura, N., Nagao, K., Asai, Y., Yokota, H., Nara, S., ... & SAVE-J Study Group. (2014). Extracorporeal cardiopulmonary resuscitation versus conventional cardiopulmonary resuscitation in adults with out-of-hospital cardiac arrest: a prospective observational study. Resuscitation85(6), 762-768.

12.  Reynolds, J. C., Grunau, B. E., Elmer, J., Rittenberger, J. C., Sawyer, K. N., Kurz, M. C., ... & Callaway, C. W. (2017). Prevalence, natural history, and time-dependent outcomes of a multi-center North American cohort of out-of-hospital cardiac arrest extracorporeal CPR candidates. Resuscitation.

13.  Grunau, B., Reynolds, J., Scheuermeyer, F., Stenstom, R., Stub, D., Pennington, S., ... & Christenson, J. (2016). Relationship between time-to-ROSC and survival in out-of-hospital cardiac arrest ECPR candidates: When is the best time to consider transport to hospital?. Prehospital Emergency Care20(5), 615-622.

 

 

 

 

When Vfib is Stubborn…

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A 56 year old male is cleaning out his garage with his wife when she hears him fall.  She turns around to find him unresponsive on the ground.  He is making gasping breath sounds but otherwise does not respond when she shakes him and yells at him.  She is instructed to perform CPR by pre-arrival instructions after calling 911 on her cellphone.  Within minutes, the BLS Fire Department arrives and takes over.  After confirming that the patient is pulseless, they resume CPR while applying an AED.   The AED states “shock advised” for ventricular fibrillation.  After resuming CPR after one shock is delivered, the ALS ambulance arrives.  High performance CPR is continued and the patient is defibrillated three more times for persistent ventricular fibrillation.  The end-tidal CO2 is 40 mmHg.   The patient has now been pulseless for almost twenty minutes.  The paramedics plan on continuing high performance CPR, but wonder what they will do if the patient remains in ventricular fibrillation with a good end-tidal 10 minutes from now…

As we have improved the care of patients in out-of-hospital arrest, many agencies are now facilitating advanced therapies for patients with refractory ventricular fibrillation.

How does your EMS system manage these patients?  Please share your comments below.  A summary of discussion points will posted to the blog at the end of the month.

A debate of supraglottic proportions... the conclusion

supraglottic_cover.jpg

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.&nbsp;

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].

supraglottic_success_v2.jpg

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 Care18(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. Anaesthesia63(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 anesthesiology12(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 Res5(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. Anaesthesia64(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. Anaesthesia66(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 sciences4(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 Anesthesia23(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 Anesthesiologists111(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 anaesthesia6(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. Anaesthesia63(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. Resuscitation85(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 & Analgesia102(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. Resuscitation82(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. Resuscitation83(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 Care13(4), 541-545.

18.  Guyette, F. X., Wang, H., & Cole, J. S. (2007). King airway use by air medical providers. Prehospital Emergency Care11(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 medicine34(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 & Analgesia106(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. Resuscitation81(1), 74-77.

23.  Lutes, M., & Worman, D. J. (2010). An unanticipated complication of a novel approach to airway management. The Journal of emergency medicine38(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 Medicine23(3).

25.  Carlson, J. N., Mayrose, J., & Wang, H. E. (2010). How much force is required to dislodge an alternate airway?. Prehospital Emergency Care14(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. resuscitation119, 1-4.

A debate of supraglottic proportions...

supraglottic_cover.jpg

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?

Read the Case Conclusion here.

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

A Case

It is a typical day in the emergency department. An 83 yo female is brought in by EMS after family called 911 because the patient was not herself.  The patient’s vital signs are reportedly within normal limits, so she is triaged to a regular room in the emergency department where handoff is given from paramedic to nurse.  The physician, who is in another room, is not present for the signout. Ten minutes later, the physician walks into the room to see the patient.  Her family is not present.  Because paramedics had to leave rapidly for another call, the prehospital patient-care record is not in the chart and there is minimal documentation of what was communicated in the handoff.  The patient, who is oriented only to self, states only, “I’m not sure why I’m here.”  The physician continues with his physical exam, hoping he can find other clues as to why the patient is here. 

A couple weeks ago, we asked our readers to consider this case and discuss the following questions:

What are some of the barriers you have encountered to quality patient handoffs from prehospital to in-hospital providers ?

Most importantly, what initiatives has your EMS system implemented to address this issue in patient care?

Below you will find a summary of this discussion.

Discussion Summary

Handoffs are defined as the transfer of information, professional responsibility and accountability between caregivers.  Whenever they occur, handoffs are a critical component of quality patient care and have enormous influence on patient trajectory within the clinical environment.  Failures of communication during transfer of patient care are major drivers of error and patient harm within the current healthcare system [1,2].

For a multitude of reasons, handoffs between prehospital and in-hospital clinicians are logistically difficult and vary in quality.  A quantitative analysis of the content of 90 EMS to ED handoffs involving critically ill patients found significant deficiencies in information transfer [3].  Only 78% (95% CI, 70.0-86.7) of handoffs included a chief concern, 47%(95% CI 31.3 – 57) included pertinent physical exam findings, and 58% (95% CI 47.7 – 67.7) provided a description of the scene. The reason for such omissions is likely multi-factorial.  A qualitative study of EMS provider focus group-based discussions of handoffs identified some common themes [4].  EMS providers expressed frustration with a disorganized process that inhibited their ability to act as patient advocates.  Disorganization was predominantly due to lack of time, focus, standardization, and respect for the healthcare role of the EMS provider. When asked to comment on “barriers to quality handoffs”, our readers focused on these themes as well:

Bedside handover needs to be distinct from moving the patient to the bed. Singular focus.
— Jon Kavanaugh
Triage nurses (or whoever) must be on the same page as EMS with a standardized, mutually agreeable, report format.
Instead, everyone is doing their own thing and there is no consistency.
As a medic, in one shift I can effectively go from “name, date of birth,and complaint—don’t tell me anything else” to “why aren’t you giving me a full report?”
Tell me what you want and I’ll work with you!
But if you don’t want any information, you won’t have it later
— S. Benson

Interruptions are the norm in the chaotic environment of the emergency department.  In one study, emergency physicians were interrupted 9.7 times per hour and spent 6.4 minutes out of every hour performing simultaneous tasks [5].  Following such interruptions, emergency physicians failed to return to a significant percentage (19%) of tasks. In one study of emergency department communication, 30.1% of communication events were found to be interruptive and 10% of communication time involved two or more concurrent conversations [6].  Interruption is the cultural and operational norm of the emergency department, including during times of information transfer.  This undoubtedly leads to information loss and negatively impacts patient care.  The question remains: how do we fix it?

One of the major themes that emerged from our reader’s comments was that of standardization:

I think a standard handover tool between EMS and hospital providers is essential and helps ensure that just the important information that both parties are interested in are transmitted
— Tom Grawey
Multi-provider and multi-hospital systems are complicated—everyone needs to work together. Standard handover tools are good but need to be standard and work for both EMS and ED. EMS needs to be educated as to the failures in their current methods.
— Jon Kavanaugh
Here in Holland all (para)medics are also RN’s (specialized in ER/ED and/or ICU) so that helps to be on the same page. With the handoff the ER doc is always present (or at least should be) and we use the SBARR method ( Situation, Background/pt Hx, Assessment, Results of treatment given, Recommendation) for all patients that we bring to the ED in the handoff and a full report we send by Ipad.
— Hans S. Medic and RN (ER)

Indeed, in a joint statement, NAEMSP, the American College of Emergency Physicians (ACEP), Emergency Nurses Association (ENA), National Association of Emergency Medical Technicians (NAEMT) and the National Association of State EMS Officials (NAEMSO) wrote that a “clearly defined processes for the contemporaneous face-to-face communication of key information from … EMS providers to health care providers in an emergency department are critical to improving patient safety, reducing medicolegal risk, and integrating EMS with the healthcare system.” [7]. But is standardization of the handoff process effective in improving the quality of information transfer?

In 2007, a study was published that evaluated the effect of implementing a standardized tool on retention of information by ED staff following EMS handoffs [8].  The study measured information recall by the ED staff during unstructured handoffs versus handoffs structured in the “DeMIST” format: Demographics, Mechanism of injury/illness, Injuries (sustained and suspected), Signs (including observation and monitoring), and Treatment given.  Overall, they reported a non-significant decrease in information retained after implementation of the standardization tool (from 56.6 to 49.2%), which is disheartening until the study is evaluated more closely.  First, only EMS providers were trained in the format, and this training was minimal.  Second, only 18 unstructured handoffs and 10 structure handoffs were evaluated. Therefore, the take-home of this study is not that standardization is ineffective, but that simply changing the format of the handover, rather than the process of the entire system (EMS and ED) is ineffective in creating change.

On the hospital side, there is some evidence that standardization of information transfer can be effective in improving patient-centered outcomes.  A very large study of the effect of implementing a standardized handoff tool for pediatrics residents (I-PASS) found a 23% decrease in the medical-error rate in 10,740 patient admissions [2].  Importantly, the intervention was not limited to the mnemonic itself, but included extensive education, resident feedback, and a culture-change campaign.

One of our readers commented specifically on a local initiative in standardization:

The regional EMS council encompassing Rochester, NY implemented [a standardized handoff process] last year. While not universally utilized (on either side of the transition), when it is the transfer of care is noticeably smoother
— Jon L
Source: https://www.mlrems.org/patient-handoff/ems-toolkit/

Source: https://www.mlrems.org/patient-handoff/ems-toolkit/

The Monroe-Livingston Region in upstate New York enacted a program entitled “Effective Patient Handoffs”.  This program employs a standardized MIST handoff tool for the transfer of information (see Figure).  Moreover, it requires that information transfer is the singular focus of the interaction (i.e. occurs prior to and not simultaneously with movement of the patient).  It is not a unilateral initiative, but elicited the collaboration of emergency departments in the area.  Educational videos and posters are provided on the website.  Based on the I-PASS study, such tools are essential to creating the cultural change to enable effective implementation.

 But verbal communication is only part of the communication between EMS and the ED.  As noted by the joint statement by NAEMSP, ACEP, ENA, NAEMT and NAEMSO, “verbal information alone may lead to inaccurate and incomplete documentation of information and inadequate availability of information to subsequent treating providers… who are not present at the verbal communication.” [7].  Indeed, the study of the DeMIST handoff tool reinforced this concept by demonstrating that only about half of information is retained following the verbal transfer of information [8].  Several of the comments addressed the importance of written documentation during transfer of information:

I think a good triage note from the RN taking the bedside is also important when the physician is unable to talk to EMS. With EHRs the ability to standardize this and ensure that pertinent EMS information is documented directly in the patient’s chart is fairly simple.
— Tom Grawey
…and a full report we send by Ipad.
— Hans S. Medic and RN (ER), Holland
The runsheet needs to be valued by both EMS and ED. Completed and submitted to the server in a short period of time.
— Jon Kavanaugh

EMS documentation is part of the healthcare record, but counter to this fact, many EMRs fail to integrate prehospital information into the patient’s permanent care record.  Beyond written documentation of the handoff by the direct receiver (triage note), the EMS patient care record, including prehospital testing such as glucose measurement and ECG, are often unavailable within a clinically relevant period of time.  While most electronic records are designed to capture billing information, we must remain vigilant that they effectively perform what should be their primary role – efficient transfer of information for patient benefit.  While we wait for technology to catch up (as it has in other parts of the world such as Holland per our reader’s comments), we must remain consistent in recognizing the value of prehospital written documentation.

Take Home

The handoff between EMS and the ED is a critical moment in patient care.  As clinicians working in the prehospital environment, emergency department or both, we must change both the process and culture surrounding verbal and written documentation if we are to do the best for our patients.

If you read this article, please consider completing the following survey:

Discussion summary by EMS MEd Editor, Maia Dorsett MD Phd (@maiadorsett)

References

1. Joint Commission. (2016). Sentinel event data: root causes by event type, 2004–2015. PowerPoint slides, Retrieved from the Joint Commission website) http://www. jointcommission. org/sentinel_event. aspx.

2. Starmer, A. J., Spector, N. D., Srivastava, R., West, D. C., Rosenbluth, G., Allen, A. D., ... & Lipsitz, S. R. (2014). Changes in medical errors after implementation of a handoff program. New England Journal of Medicine371(19), 1803-1812.

3. Goldberg, S. A., Porat, A., Strother, C. G., Lim, N. Q., Wijeratne, H. S., Sanchez, G., & Munjal, K. G. (2017). Quantitative analysis of the content of EMS handoff of critically ill and injured patients to the emergency department. Prehospital Emergency Care21(1), 14-17.

4. Meisel, Z. F., Shea, J. A., Peacock, N. J., Dickinson, E. T., Paciotti, B., Bhatia, R., ... & Cannuscio, C. C. (2015). Optimizing the patient handoff between emergency medical services and the emergency department. Annals of emergency medicine65(3), 310-317.

5. Laxmisan, A., Hakimzada, F., Sayan, O. R., Green, R. A., Zhang, J., & Patel, V. L. (2007). The multitasking clinician: decision-making and cognitive demand during and after team handoffs in emergency care. International journal of medical informatics76(11), 801-811.

6. Coiera, E. W., Jayasuriya, R. A., Hardy, J., Bannan, A., & Thorpe, M. E. (2002). Communication loads on clinical staff in the emergency department. The Medical Journal of Australia176(9), 415-418.

7. American College of Emergency Physicians, Emergency Nurses Association, National Association of EMS Physicians, & National Association of State EMS Officials. (2014). Transfer of patient care between EMS providers and receiving facilities. Prehospital emergency care: official journal of the National Association of EMS Physicians and the National Association of State EMS Directors18(2), 305.

8. Talbot, R., & Bleetman, A. (2007). Retention of information by emergency department staff at ambulance handover: do standardised approaches work?. Emergency Medicine Journal24(8), 539-542.

 

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.

Grawey_bio.001.jpeg

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.

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.

 

Should EMS providers administer Ondansetron for pregnancy-related vomiting?

Summary and analysis by Maia Dorsett, MD, PhD     @maiadorsett

Framing the Problem

Nausea and vomiting in pregnancy is not rare, occurring in about 50% of all pregnant women. [1]  Symptom onset typically occurs within four weeks of the last menstrual period and peaks at nine weeks of gestation, with the vast majority of cases resolving by 20 weeks. The most severe form, hyperemesis gravidarum, is characterized by persistent vomiting, weight loss of more than 5%, ketonuria, electrolyte abnormalities and dehydration. [1]  This occurs in a minority of patients (0.3 to 1.0%), although patients with a less severe form may also access the emergency department by utilization of ambulance services. [1]  The frequency of EMS utilization for patients with hyperemesis gravidarum is unclear.

With regard to the most effective treatment of hyperemesis, the proverbial wind has blown in several directions.  Lessons learned from the tragedy of thalidomide, used in the late 1950’s as a treatment for nausea in pregnant women before being banned in 1961 due to severe teratogenic effects, have raised the bar of safety considerations for the administration of medications to pregnant women. [2] Partially in response to the thalidomide tragedy, in 1979 the FDA established five letter risk categories - A, B, C, D or X - to help clinicians evaluate the risk versus benefit of medication use in pregnancy (see Figure, [3]).  However, the pregnancy letter categories were often falsely interpreted to be an interpretation of teratogenic risk, leading to misunderstanding among clinicians and patients.   Recently, the FDA has recommended eliminating the letter categories in favor of the Pregnancy and Lactation Labeling Final Rule (PLLR) that went into effect on June 30, 2015 .  The PLLR requires a description of the “risk summary” and associated data regarding safety or harm in pregnancy and lactation. 

The anti-emetic ondansetron is approved by the FDA for the treatment of nausea and vomiting associated with chemotherapy or surgery.  However, its effectiveness at treating nausea and vomiting with little sedating side effects, as well as its classification as pregnancy category “B”, has now made it the most commonly used prescription oral antiemetic in pregnancy (at least in 2008). [4,5]  More than half of women treated in emergency departments will receive intravenous ondansetron. [4,6]  Retrospective cohort studies published in 2013 and 2014 came to conflicting conclusions regarding the safety of ondansetron in pregnancy, with one article finding a slight increase in the risk of cardiovascular defects. [see below for more in-depth review; 7,8]  In September 2015, the American Society of Obstetricians and Gynecologists published a Practice Bulletin on Nausea and Vomiting in pregnancy.  This practice bulletin recommended doxylamine and pyridoxine as first line treatment, and wrote that:

There are insufficient data on fetal safety with ondansetron use and further studies are warranted…. Thus, although some studies have shown an increased risk of birth defects with early ondansetron use, other studies have not and the absolute risk to any fetus is low. As with all medications, the potential risks and benefits should be weighed in each case.” [5]

From the perspective of the EMS provider, should we giving ondansetron to pregnant women in their first trimester with nausea and vomiting?  Our discussion forum reviewed one such case.

 

Case and Discussion

The Case:

EMS is called to the house of a 24 yo female who is 8 weeks pregnant.  She has had countless episodes of nausea and vomiting over the last 4 days.  She has been unable to take anything by mouth over this period and has not urinated in the last day.  Heart rate is 115, blood pressure 101/60.  The crew starts an IV and begins administration of IV fluids.  The patient asks if they can give her anything for the nausea on the way to the hospital.  The current protocol for nausea and vomiting recommends administration of 4 mg of IV ondansetron.  Should the paramedics give it?

Multiple perspectives/comments regarding the case were shared (thanks to all who contributed!).  These comments can be separated into a number of points or themes:

Theme #1Outpatient treatment of nausea and vomiting is a clinically distinct situation from the acute management of intractable vomiting.

“I'd just be careful with that guideline. I generally do use B6 & pyridoxine but that is after they stop vomiting. I think people with some nausea & vomiting who can manage their symptoms at home are different than those that are coming to the ED as they can't stop vomiting and need a SL or IV medication.” – E. Schwarz

 

“I agree with Evan that pyridoxine (vitamin B6) is helpful in reducing the tendency toward nausea & vomiting in pregnancy, but it is not an immediately effective treatment for HG even when given IV (which I sometimes do since the woman may have continued difficulty with oral intake and absorption).” – M. Mullins

This is a really important point.  We often inappropriately extrapolate general recommendations from one clinical situation and apply them to another.  The ACOG guidelines refer to treatment of nausea and vomiting in pregnancy, the majority of which is treated at home.  The patient population using EMS for refractory vomiting and/or have hyperemesis gravidarum is different from those who would tolerate oral doxylamine and pyridoxine.  Even when it comes to oral treatment, one small randomized trial involving 36 women compared 5 days of treatment with ondansetron versus doxylamine/pyridoxine. [10] This study found that ondansetron was superior in reducing nausea/vomiting in pregnancy.   The ACOG guidelines write that “the potential risks and benefits should be weighed in each case”,  leaving room to use alternatives to doxylamine and pyridoxine in a patient who is not tolerating oral intake or with clinical signs of dehydration. 

Theme #2:  The data regarding ondansetron and birth defects is not particularly convincing and most EMS protocols do not distinguish between pregnant and non-pregnant patients when it comes to the treatment of nausea/vomiting.

“In addition, many are still not convinced that ondansetron is truly problematic in pregnancy.” – E. Schwarz

 

“no limitations to choice of anti-emetic at my agency.” – S. Pearson

 

“I remain unconvinced the Ondansetron is a cause of birth defects rather than being associated with problem pregnancies with more nausea. Although it may or may not be effective in HG, it is Category B and remains the first line anti-emetic for paramedics in the field.” – M. Mullins

 

“Our (statewide) protocols use ondansetron as first-line treatment for nausea/vomiting, and do not exclude or distinguish between pregnant and non-pregnant patients. The most recent data on the subject (Ondansetron in pregnancy and risk of adverse fetal outcomes in the United States. Reprod Toxicol. 2016 Jul;62:87-91.) is reassuring and throws into question the previously reported association with cardiac defects.” – M. Holtz

 

The overall prevalence of cardiac or major congenital anomalies is low, and therefore one should have larger sample sizes to detect an increase in teratogenic risk.  To date, there are only three peer-reviewed and published studies with greater than 1000 pregnancies with ondansetron exposure that have evaluated for an association between ondansetron and birth defects.  Given the inability to perform a randomized-control trial to evaluate for risk of birth defects due to ethical concerns, all three of these studies are retrospective cohort studies.

                  1. Pasternak et. al. (2013) [7]: This was a cohort study of 441,511 pregnancies in Denmark utilizing data from the National Patient Register and medical Birth Registry from 2004-2011.  The authors studied women with ondansetron exposure prior to the 12th week of pregnancy (1233 pregnancies) and matched these to unexposed women (4,932 pregnancies).  After adjusting for possible confounding variables (including hospitalization for hyperemesis and maternal comorbidities including diabetes), the authors did not find any significant association between ondansetron-exposure and the incidence of major birth defects (OR 1.12, 9%% 0.69 – 1.82) or cardiovascular defect (OR 1.04, 95% CI 0.52 – 1.95). 

                  2. Danielsson et. al. (2014) [8]: This retrospective cohort study in Sweden identified women through midwife interviews at the first antenatal visit and through the Swedish Prescription Drug registry. The study included approximately 1.5 million births, with 1349 ondansetron-exposed infants. They did not find a significant difference in risk of “major malformation” (OR 1.11, 95% CI 0.81-1.53).  However, they did find a slightly increased risk of cardiovascular defects in the ondansetron-exposed group (OR 1. 62, 95% CI 1.04-2.14).

                  3. Fejzo et. al. (2016) [11]: This was a retrospective cohort study of women in the United States recruited through the Hyperemesis Education and Research Foundation between 2007 and 2014.  Normal controls were recruited by study participants.  The study recruited women in three groups: (1) Hyperemesis with ondansetron (1070 pregnancies), (2) Hyperemesis without ondansetron (771 pregnancies), and (3) No hyperemesis without ondansetron (1555 pregnancies).  Participants filled out online surveys on fetal outcome following their due date.  They found that the rate of birth defects was equally reported among the HG groups (3.47% in HG/ondansetron group vs. 3.40% in HG/no ondansetron group, p = 1.0), and increased in comparison to the control group (1.87%), suggesting that birth defects may be associated with problem pregnancies with more nausea. They also found that women with a history of HG who took ondansetron were significantly less likely to report miscarriage or termination of their pregnancy due to hyperemesis gravidarum.  This study was limited by potential recall bias, as these were all self-reported outcomes.

The combination of dicyclomine and pyridoxine was transiently taken off the market in 1983 because of allegations of teratogenicity only to be reinstated later as first line therapy and the first FDA-approved treatment for hyperemesis gravidarum [1].  We will see what the future holds for ondansetron, but the above evidence is far from convincing of direct teratogenic effects of ondansetron-exposure rather than confounding effects.

 

Theme#3:  What about alternatives?

“Actually, if you look at a drug's mechanism of action, metoclopramide makes a lot more sense than ondansetron. Metoclopramide lowers GI esophageal sphincter tone and speeds gastric emptying, precisely the opposite of what progesterone does to the pregnant woman's GI system. It puzzles me that we target antibiotics mechanistically to treat microbes, yet we don't target anti-emetics to treat nausea based on the presumed cause. I'm just sayin.... I have treated several ondansetron-refractory ladies with metoclopramide with excellent results (And by the way, if you are worried that Metoclopramide may not be as "safe" as ondansetron, perish the thought. Metoclopramide, just like ondansetron, is "Class B")” – G. Gaddis

 

Within the scope of retrospective data, Metoclopramide appears to be safe in pregnancy.  A retrospective cohort study involving 113, 612 pregnancies with 3458 exposures to metoclopramide in the first trimester of pregnancy found no increased risk of adverse outcomes. [12] In a randomized-control trial of ondansetron and metoclopramide for hyperemesis gravidarum, the two drugs performed comparably in nausea-reduction, but there was more reported side-effects of drowsiness and dry mouth in the metoclopramide-treated group. [13]

 

Take Home Points

The evidence that ondansetron causes harm in pregnancy is far from conclusive.  As EMS takes care of women with more severe symptoms, intravenous ondansetron can be considered as a therapy in pregnant women who present with intractable nausea and vomiting.

 

References:

1. Niebyl, J. R. (2010). Nausea and vomiting in pregnancy. New England Journal of Medicine, 363(16), 1544-1550.

2. Kim, J. H., & Scialli, A. R. (2011). Thalidomide: the tragedy of birth defects and the effective treatment of disease. Toxicological Sciences, 122(1), 1-6.

3. Mospan C. New Prescription Labeling Requirements for the Use of Medications in Pregnancy and Lactation. CE for Pharmacists. Alaska Pharmacists Association. April 15, 2016. Accessed July 25, 2016 at http://www.alaskapharmacy.org/files/CE_Activities/0416_State_CE_Lesson.pdf

4. Siminerio, L. L., Bodnar, L. M., Venkataramanan, R., & Caritis, S. N. (2016). Ondansetron use in pregnancy. Obstetrics & Gynecology, 127(5), 873-877.

5. Mitchell, A. A., Gilboa, S. M., Werler, M. M., Kelley, K. E., Louik, C., Hernández-Díaz, S., & Study, N. B. D. P. (2011). Medication use during pregnancy, with particular focus on prescription drugs: 1976-2008. American journal of obstetrics and gynecology, 205(1), 51-e1.

6. Mayhall, E. A., Gray, R., Lopes, V., & Matteson, K. A. (2015). Comparison of antiemetics for nausea and vomiting of pregnancy in an emergency department setting. The American journal of emergency medicine, 33(7), 882-886.

7. Pasternak, B., Svanström, H., & Hviid, A. (2013). Ondansetron in pregnancy and risk of adverse fetal outcomes. New England Journal of Medicine, 368(9), 814-823.

8. Danielsson, B., Wikner, B. N., & Källén, B. (2014). Use of ondansetron during pregnancy and congenital malformations in the infant. Reproductive Toxicology, 50, 134-137.

9. Goodwin, T. M., & Ramin, S. M. (2015). Practice Bulletin Summary No. 153: Nausea and Vomiting of Pregnancy. OBSTETRICS AND GYNECOLOGY, 126(3), 687-688.

10. Oliveira, L. G., Capp, S. M., You, W. B., Riffenburgh, R. H., & Carstairs, S. D. (2014). Ondansetron compared with doxylamine and pyridoxine for treatment of nausea in pregnancy: a randomized controlled trial. Obstetrics & Gynecology, 124(4), 735-742.

11. Fejzo, M. S., MacGibbon, K. W., & Mullin, P. M. (2016). Ondansetron in pregnancy and risk of adverse fetal outcomes in the United States. Reproductive Toxicology, 62, 87-91.

12. Matok, I., Gorodischer, R., Koren, G., Sheiner, E., Wiznitzer, A., & Levy, A. (2009). The safety of metoclopramide use in the first trimester of pregnancy. New England Journal of Medicine, 360(24), 2528-2535.

13. Abas, M. N., Tan, P. C., Azmi, N., & Omar, S. Z. (2014). Ondansetron compared with metoclopramide for hyperemesis gravidarum: a randomized controlled trial. Obstetrics & Gynecology, 123(6), 1272-1279.