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. 

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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 #1:  Outpatient 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.

Prehospital Ketamine: The sweet ain't as sweet without the sour

By: Hawnwan Philip Moy MD @pecpodcast

Expert Reviewed by: Minh Le Cong MD @ketaminh

Case Scenario

It’s an unusually warm Halloween night and you, the medical director, are riding along with the EMS supervisor when you hear Medic 2 urgently request assistance on scene with a “bizarre behavior” patient.  Your supervisor gives you a side long glance and says, “...And we were having such a good night!”  He quickly puts his truck in gear and you both speed off to the scene.

On arrival...you find a large, athletic male patient in his 30s, who is only wearing purple, tattered pants, painted green, screaming, “Hulk Smash!!!” as he proceeds to...well...SMASH EVERYTHING!!!

You get a quick report from your exasperated paramedic: “This is a 30 year old male with no past medical history (we think) who took A LOT of...SOMETHING.  We (2 fireman, 2 policeman, and his partner) pinned him down and tried to de-escalate him verbally...but he’s still Hulking out!  What do we do?" 

As the patient turns to you (UH OH!) and you ask yourself...is it time to use our Ketamine protocol?  You remember reading that Ketamine can help sedate these patients...but is Ketamine safe to use in the prehospital environment?  What are its pros and cons?!?!?

Fortunately, with your adrenaline-filled, razor sharp mind is firing on all cylinders... time slows down and you quickly recall the your most up to date research on Ketamine.

Background

Excited Delirium (ExDS) is a syndrome described by the American College of Emergency Physicians (ACEP) as those patients with altered mental status who demonstrate severe agitation with combative and/or assaultive behavior.  Also known as Agitated Delirium, Excited Derlium, or Sudden Death in Custody Syndrome, ExDS is characterized by the following [1, 2]:

• Hyper-aggressive or Bizarre behavior

• Lack of Sensitivity to Pain

• Hyperthermia

• Diaphoresis

• Attraction to light or shiny objects

The scariest thing about ExDS is not just the harm it can do to our prehospital providers, but the harm it could cause to the patient himself.  These patients can die with mortality rates of up to 10% with causes that are relatively unknown (click here to see ExDS from the beginning to the death of the patient) [1, 2].  Many prehospital providers are called to utilize a variety of medications (see below) to try to sedate the patient before harm to providers or harm to the patient himself can occur [3]. 

3. Vilke, G. M., Bozeman, W. P., Dawes, D. M., DeMers, G., & Wilson, M. P. (2012). Excited delirium syndrome (ExDS): treatment options and considerations. Journal of forensic and legal medicine, 19(3), 117-121.

At present, the most popular medications for chemical restraint are Benzodiazepines with Antipsychotics.  Unfortunately, Benzodiazepines have a relatively long onset (18 minutes) as do antipsychotics like Haldol (17 min)[4-7].  These prolonged times place prehospital providers at a higher risk of physical harm.

To attempt to ameliorate this inefficiency, researchers have decided to visit our old friend Ketamine as a potential treatment option.

Literature Review

Ketamine

the good, the bad, and the ugly

In 2014, Scheppke et al. retrospectively studied 52 agitated patients who were given 4mg/kg IM of Ketamine8.  The average time to sedation was 2 minutes (yeah!).

However, 3/52 patients had significant respiratory depression with 2 of those 3 patients requiring intubation in the Emergency Department (ED).  Should we be concerned?  Maybe.  On one hand, intubating is a high risk procedure and should make every medical director a little squeamish.  However,  those three respiratory depressed patients also received IV Midazolam to prevent an emergence reaction.  As a result Scheppke et al. concluded that “Ketamine may be safely and effectively used by trained paramedics following a specific protocol.” A major limitation to this study is that the authors did not evaluate outcomes of these patients in the ED.  However, so far so good for Ketamine in that 1) providers can provide it safetly and 2) it works pretty darn fast.

Earlier this year (2016), Cole et al. performed a prospective study in their urban/suburban midwest community that services approximately 1,000,000 citizens while transporting 70,000 patients a year [9].  To minimize bias from seasonal changes, this service provided 10 mg of Haldol intramuscularly (IM) for severely agitated patients (defined as an altered mental status score of 2 or 3) for the first 3 months of the year.  Subsequently,  the authors changed the sedation medication to Ketamine 5mg/kg IM for the next 6 months.  Afterwards, in the final three months of the year, they switched the sedative medications back to Haldol.  So what did they observe?  A total of 146 patients were treated with a median time for sedation of 5 minutes compared to Haldol’s 17 minutes to sedation.  It appears that time to sedation using Ketamine was much faster in making the scene safe for our providers...but at what cost?!?!

 It turns out that the Ketamine cohort had more side effects with more patients vomiting, more patients suffering laryngospasm (5% compared to 0.3%), and more patients being intubated (an intubation rate of 39% in the Ketamine cohort compared to 4% in the Haldol cohort).  

Now, before we jump to any drastic conclusions about airway compromise, let’s take a little deeper dive into these intubated patients of this study.  First, there was no association with the dosage of Ketamine and intubation rates.  Next, the reasons for intubating these patients were documented as “Not Protecting Airway NOS.”  Cole et al hypothesized that perhaps receiving physicians may be uncomfortable receiving patients in this dissociated state or may have, “misapplied the axiom ‘intubation for a GCS of 8.’”  Certainly, those of us who are Emergency Physicians (EP),  have had drunk patients arrive in the ED with a Glasgow Coma Scale (GCS) less than 8 and let them sleep it off without even a nasal cannula.  Perhaps, when Ketamine is involved, EPs can also take this into account.  However, is it because the EP wasn’t used to dealing with patients in the K-hole or was it truly an airway issue where the EP had to secure a compromised airway?  Honestly, we can’t say for sure, but it is something to think upon when considering this manuscript for Ketamine in your system.

Finally, Olives et al. recently published their findings on the use of Ketamine (5mg/kg IM) for severely agitated patients in the prehospital environment [10].  In this 2 year retrospective study, they studied a total of 135 patients who displayed “...active physical violence to himself/herself or others and usual chemical or physical restraints may not be appropriate or safely used.”  Prehospital providers reported an initial improvement in agitation in 91.8% of ketamine treated agitated patients.  Awesome news! 

So it appears that Ketamine is safe for our providers and easy to provide.  But...wait for it...endotracheal intubation was performed on 85 patients (63%) in which 4 patients (2.96%) were intubated by prehospital providers.  Of note, laryngospasm, hypersalivation, and pulmonary edema were not listed as any complications and there was no difference (p=0.68) in the dosage of ketamine for those intubated (5.25 mg/kg IM) and those not intubated (5.14 mg/kg IM).  :(

Again, before jumping to any conclusions, let’s look at Olives et al’s analysis of those intubated patients.  Among the four patients in whom prehospital intubation was undertaken, one experienced post ketamine vomiting and jaw clenching resulting in intubation and another suffered severe hypoxemia.  Fair enough.  The other two patients were combative, altered on scene, and required both physical and chemical restraints.  After sedation both patients went into cardiac arrest and died.  The medical examiner determined that cause of death was Citalopram and Amphetamine toxicity for one patient and seizure disorder, sub therapeutic dose of valproic acid, hypertension and history of substance abuse for the other patient.  Essentially, Ketamine nor hypoxia was not deemed to be the cause of the patient’s death.  However...did Ketamine exacerbate the situation or help?  Again hard to say.  Now for the other 81 patients intubated in the ED.  Olives et al. found that intubation had a higher association if they were male and presented to the ED overnight.  More interestingly, among the 31 staffed EPs at that facility, two providers accounted for 50.9% (28/55) of overnight encounters, but 65.9% (27/41) of overnight intubations.  The same two providers comprised just 7.5% (6/80) of daytime encounters, but 11.4% (5/44) of all daytime intubations.  So could this be physician practice, resource availability associated with time of day, or staffing that justified intubation?  Again, it is hard to say, but certainly something to consider when looking at these numbers.  Of note, arterial PH of those intubated versus those not intubated were similar (7.33 v. 7.32), lactate was slightly higher in the non intubated group (5.6 v. 7.05), and ethanol levels were similar as well (0.18 g/dL v. 0.19 g/dL).  At least physiologically, intubated versus nonintubated groups appeared to be very similar, suggesting that intubation was more of a clinical decision.  Again this is hard to tell as this is sometimes difficult to articulate in medical charts.   

Bottom Line:

Overall, ExDS is dangerous for both our patients and our providers in the field.  Ketamine is one shield that we can use to help sedate our patients and keep our providers safe.

It has a great treatment profile, especially for prehospital care in that it sedates quickly, can be administered in a safe manner, and has a relatively short duration of action.  However, the sweet ain’t as sweet without the sour. There are those side effects that you have to watch out for...mainly airway issues that are up for debate, but should be considered.  That being said, there is always a risk-benefit assessment in everything we do in medicine. In a prehospital environment, the benefits of Ketamine administration for quick and safe sedation in a truly chaotic, dangerous environment does appear to outweigh the risk to your providers.  More importantly, Ketamine's quick sedation profile protects your patients from themselves and the harms of physical restraint. Thus, if you decide to use Ketamine in your system, ensure that you have adequate safeguards within your protocols to monitor airways (i.e. ETCO2 & paramedic training) as well as assuage receiving facility's discomfort by informing them that Ketamine may be provided in the prehospital environment, careful monitoring of these patients is important, and GCS <8 may not always indicate intubation (i.e. we do not intubate every inebriated patient in the ED).  

Bonus:

For your entertainment, here is a video of when I had to be procedurally sedated with Ketamine and Propfol.  I suffered a nasty open left subtalar ankle dislocation (there are pics, ask me about them via email or at the NAEMSP Conference and I'll show them to you!).  I have no recollection of this at all...but man...what a video! We swear there no editing was done :)!  Enjoy and Happy Holidays!

References:

1. Vilke, G. M., DeBard, M. L., Chan, T. C., Ho, J. D., Dawes, D. M., Hall, C., ... & Bozeman, W. P. (2012). Excited delirium syndrome (ExDS): defining based on a review of the literature. The Journal of emergency medicine, 43(5), 897-905.

2. Vilke, G. M., Payne-James, J., & Karch, S. B. (2012). Excited delirium syndrome (ExDS): redefining an old diagnosis. Journal of forensic and legal medicine, 19(1), 7-11.

3. Vilke, G. M., Bozeman, W. P., Dawes, D. M., DeMers, G., & Wilson, M. P. (2012). Excited delirium syndrome (ExDS): treatment options and considerations. Journal of forensic and legal medicine, 19(3), 117-121.

4.  Nobay F, Simon BC, Levitt MA, Dresden GM.  A prospective, double-blind, randomized trial of midazolam versus haloperidol versus lorazepam in the chemical restraint of violent and severely agitated patients.  Acad Emerg Med.  2004; 11(7):744-749.

5. Spain D, Crilly J, Whyte I, Jenner L, Carr V, Baker A.  Safety and effectiveness of high-dose midazolam for severe behavioral disturbance in an emergency department with suspected psychostimulant-affected patients.  Emerg Med Australas.  2008; 20(2):112-120.

6. Isbister GK, Calver LA, Page CB, Stokes B, Bryant JL, Downes MA.  Randomized controlled trial of intramuscular droperidol versus midazolam for violence and acute behavioral disturbance: the DORM study.  Ann Emerg Med.   2010;56(4):392-401.c1.

7. Takeuchi A, Ahern TI, Henderson SO.  Excited Delirium.  West J Emerg Med.  2011;12(1):77-83.

8.  Scheppke, K. A., Braghiroli, J., Shalaby, M., & Chait, R. (2014). Prehospital use of IM ketamine for sedation of violent and agitated patients. Western Journal of Emergency Medicine, 15(7), 736.

9. Cole, J. B., Moore, J. C., Nystrom, P. C. et al. (2016). A Prospective study of ketamine versus haloperidol for severe prehospital agitation.  Clinical Toxicology, 54(7), 556-562.

10.  Olives, T. D., Nystrom, P. C., Cole, J. B., Dodd, K. W., Ho, J. D. (2016).  Intubation of Profoundly Agitated Patients Treated with Prehospital Ketamine. Prehospital and Disaster Medicine, 31(6), 1-10.  

Medicine in Public: Messaging is a Core Skill in EMS Education

Sabina Braithwaite, MD, MPH, NRP, FACEP

The current EMS Fellowship curriculum emphasizes clinical skills needed to be a competent EMS physician.  In addition to medical knowledge, prehospital patient care, and systems-based practice, there are milestones for team and patient centered communication. These milestones focus on communication between EMS physician and EMS providers, EMS physician and patient, but do not expressly focus on communication between EMS physician and the public in general.

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But unlike many other subspecialities of medicine, EMS is largely performed in public venues, now under the ever-watchful (and recording) eye of social media.  When taking care of complex patients in a complex system, it is guaranteed that bad things will happen. When that day comes (and it will), EMS physicians must be prepared to be questioned privately, in public, on TV, in front of a county commission hearing, and who knows where else, about what their role in the EMS system is and why that bad thing happened. 

Knowing this, we must make sure to prepare postgraduate EMS physicians with  additional communication skills that are at best under-emphasized in the current curriculum.  These skills are absolutely central to success as an EMS physician specifically, but also more broadly in any administrative role taken on.

One of these key skills is “messaging.”  A message is a brief, value-based statement aimed at a targeted audience that captures a positive concept.  This means that even when addressing a negative subject, the message should be positive.  Without a firm grasp on messaging, it is pretty easy to get into trouble in any of a number of ways when bad things happen.

So how do you become effective at messaging?  Here are my Top 6 tips: 

1.      Proactively work to get a positive public image.  This isn’t too hard to do: EMS are the “good guys” that help people in need.  But get that positive message out in front of the public, the funders (county / state government), and whoever else needs to know BEFORE the bad thing happens.  Develop a positive relationship with your print / TV media so they know they can call on you for facts when “it” hits the fan.  Get a reputation as an accessible expert who is part of a large team of folks there to help the public.  Volunteer to do a piece on heat exhaustion in the summer when it gets hot, pool safety for Memorial Day weekend, etc.  Every TV station in the land does those same pieces every year, and they will love you for not making them hunt someone down.  That way when you almost inevitably end up in front of a microphone / camera on a bad day, at least you will have done it before under non-confrontational circumstances.

2.      Always force yourself to write down the two or three bullet points that are the major message you want to get across.  You have time to do this no matter what, and it will keep you focused so you don’t wander off down some rabbit hole.  Have a “hook” that you can go back and rephrase, reiterate and come back to during the interview to emphasize your point.  Remember the KISS principle (Keep It Simple, Stupid).  Have a couple strong facts to support your points.  Anticipate the negative questions you will likely be asked and have an answer ready.  And shut your mouth and stop making sounds when you have made your point.  Resist the urge to over-explain.

Example:  Your system plans to start field cease resuscitation for OOHCA.  The public’s biggest concern will be that patients aren’t getting as high a level of care as they would if they were in a hospital [negative].  So create a positive message:  We want the public to know that we are taking a new approach to cardiac arrest similar to other progressive EMS systems [of course your system is progressive, right?], and we are now bringing everything the patient would get in an emergency department right to your home, where a whole team of professionals will try to help your loved one survive neurologically intact, starting with the dispatchers who will help you start CPR, which is one of the most important factors in helping your loved one survive ….. [you get the picture, team effort, everyone is there to help you, we are bringing it all to you, your job is to do CPR when we tell you, etc. Then explain when you will transport patients to the hospital.]

3.      Tell a story that illustrates your point.  This works particularly well with legislators and government officials, because it makes it personal and helps explain the problem or issue in a way people can relate to.

Example:  when explaining change in approach to cardiac arrest to the county commission, do a demo of your new “pit crew” approach, bring a survivor along, and tell them how many more people are surviving and going back to work (not a nursing home in diapers!) because of the great teamwork approach your system is using.  

4.      Be energetic, authoritative, and human.  Don’t hide behind doctor-speak - use straightforward language.  You know your stuff – show everyone!  For in-person interviews, be very mindful of the nonverbal messages you send and be sure they are in sync with what your voice is saying.  If doing a phone interview, stand up and walk around, it gives your delivery more energy and inflection.  Be sure the interviewer knows your name (spelling), title, and role in whatever you are being asked to comment on.  Feel free to educate them on what a medical director is / does, and also feel free to offer them some questions they can ask you when you are doing a public relations-type piece, so it is more likely that your major points will get across. 

5. The microphone is always on.  Corollary:  there is no such thing as “off the record.”  And remember, the 10-20 seconds that ends up on the evening news can be any 20 seconds out of the 5-10 minutes you talked, so don’t stray off message and have comments that can be taken out of context.

6.  Most importantly, KNOW YOUR AUDIENCE.  Be sure you are tuned in to station WII-FM – “what’s in it for me?”.  If you can anticipate what your audience wants to know / is worried about / can connect with and incorporate that information into your message, you can be sure that the message you think you are sending out is also the message they actually receive.  For the public, they want to know they are getting the best care possible.  For legislators, they want to know that the public isn’t going to complain to them, and that they can truthfully tell their constituents that public funds are being expended wisely, and possibly even that they have supported some fabulous thing that you are doing in your system that has improved patient outcomes.

EMS is a uniquely public specialty of medicine.  It is therefore of paramount importance that EMS physicians – in –training are taught how to navigate medicine in the public eye.   It not only has the potential to save them a lot of heartache, but also prepare them to be more effective advocates for themselves – and most importantly – the patients we serve.

Interested in learning more?

If you ever get the opportunity to go to the Media Training offered by ACEP at Scientific Assembly or at the Leadership meeting, definitely do so, it will really open your eyes and give you valuable pointers.  There also is considerable in-depth information on this subject in the chapter in the NAEMSP textbook Vol2 Ch15:  EMS Physicians as public spokespersons.

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EMS MEd Editor: Maia Dorsett

Transporting Stroke Patients in the Era of Endovascular therapy

by Richard T. Benson II, MD, Joseph Grover, MD, Jane Brice, MD, MPH

Clinical Scenario:

EMS is dispatched to a possible stroke patient whose last seen normal time was 1.5 hours prior to dispatch.  The patient lives 15 minutes from a primary stroke center and 45 minutes from a comprehensive stroke center.  The patient has complete hemiparesis on the right, aphasia, with facial droop.  Which facility should the patient be transported to via EMS?

Literature Review:

Stroke is the fifth leading cause of death in the United States and is a major cause of adult disability [1].  About 800,000 people in the United States have a stroke each year; and on average, one American dies from a stroke every 4 minutes [1,2]. Most strokes (85%) are ischemic, meaning an artery that supplies oxygen-rich blood to the brain becomes blocked. There are also hemorrhagic strokes (15%) where an artery in the brain leaks out blood or completely ruptures. An acute stroke represents a neurologic emergency that requires time-dependent treatments to mitigate the insult. Over the past 20 years, EMS has played a vital role in the triage and management of stroke.  In 1995 an article published in the New England Journal of Medicine (NEJM) revolutionized the care of stroke patients when it demonstrated the benefit of tissue plasminogen activator (tPA) in the treatment of acute ischemic stroke [3].  Nationally, this led to the creation of Primary stroke centers – facilities capable of administering systemic tPA. Because of this, many EMS systems created specific destination plans, with the goal of getting possible stroke patients to a Primary stroke center as fast as possible. In addition, stroke scales were developed to aid providers in the early recognition of stroke. Ultimately, providers were able to appropriately triage possible stroke patients, transporting them to capable facilities, and provide pre-notification to those facilities or “Code strokes.” This decreased in-hospital delays and led to quicker dispositions and treatments. Ekundayo et al demonstrated that EMS play a major role in stroke management, transporting the majority of stroke patients (63.7%), as well as, those stroke patients with the higher stroke severity scores [4].  In 2015, almost 20 years after the FDA approved tPA for the management of stroke, the NEJM published five studies which demonstrated the superiority of endovascular treatment for Large Vessel Occlusion (LVO) strokes over the standard treatment of tPA alone. 5-9 It should be noted, that approximately 70% of the patients in the mentioned trials received intravenous (IV) tPA, in addition to endovascular treatment. This led to the creation of Comprehensive stroke centers – facilities capable to administering IV tPA and administering intra-arterial thrombolysis. These studies provide compelling evidence to support transporting LVO stroke patients to a comprehensive stroke center over primary stroke center, if available.  With EMS transporting the majority of stroke patients and those patients with the highest stroke severity scores, this fundamental change in the management of stroke patients with LVOs should have a significant impact on how EMS systems triage and transport stroke patients. 

The greatest difficulty for current EMS systems is differentiating LVO stroke patients from the standard stroke patient in the hopes of getting them to the most appropriate stroke center.  Many EMS systems utilize either the Cincinnati Prehospital Stroke Scale (CPSS) or the Los Angeles Prehospital Stroke Scale (LAPSS) for their stroke recognition.  Multiple studies have been done looking at these scales with the results showing varying sensitivities with relatively low specificities [10-11].  None of these current scales differentiate a LVO from a stroke and therefore could not aid providers in making a decision to bypass a primary stroke center for a comprehensive stroke center.  To address this need newer scales have been developed to aid providers in this regard.  The simplest scale utilizes severe hemiparesis as their sole criteria, and found 26.7% had an LVO that was treated with thrombectomy [12]. Other scales have been developed including the Cincinnati Prehospital Stroke Severity Scale (CPSSS), RACE scale, and the FAST-ED scale which show promising results in differentiating LVO from a standard stroke [13,14,15].  The associated time delays of transferring a patient from one facility to the other would likely prevent patients from receiving endovascular therapy and therefore every effort must be made to accurately triage these patients to the most appropriate facility first [16].

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Take Home Points:

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Over the past 20 years, the early recognition and treatment of strokes have come a long way, with the help of stroke scales and tPA administration. EMS has always been a key component in effective and timely management of these patients. Emerging evidence demonstrates the superiority of combined systemic IV tPA with endovascular treatment in patients with LVO over systemic tPA alone, challenging EMS systems to develop sensitive screening tools for LVO and updated destination plans.

References

1. Kochanek KD, Xu JQ, Murphy SL, Arias E. Mortality in the United States, 2013. NCHS Data Brief, No. 178. Hyattsville, MD: National Center for Health Statistics, Centers for Disease Control and Prevention, US Dept. of Health and Human Services; 2014.

2. Mozzafarian D, Benjamin EJ, Go AS, et al. Heart disease and stroke statistics—2015 update: a report from the American Heart Association. Circulation. 2015:e29–322.

3. Tissue plasminogen activator for acute ischemic stroke. the national institute of neurological disorders and stroke rt-PA stroke study group. N Engl J Med. 1995;333(24):1581-1587.

4. Ekundayo OJ, Saver JL, Fonarow GC, et al. Patterns of emergency medical services use and its association with timely stroke treatment: Findings from get with the guidelines-stroke. Circ Cardiovasc Qual Outcomes. 2013;6(3):262-269

5. Berkhemer OA, Fransen PS, Beumer D, et al. A randomized trial of intraarterial treatment for acute ischemic stroke. N Engl J Med. 2015;372(1):11-20.

6. Campbell BC, Mitchell PJ, Kleinig TJ, et al. Endovascular therapy for ischemic stroke with perfusion-imaging selection. N Engl J Med. 2015;372(11):1009-1018.

7. Goyal M, Demchuk AM, Menon BK, et al. Randomized assessment of rapid endovascular treatment of ischemic stroke. N Engl J Med. 2015;372(11):1019-1030.

8. Jovin TG, Chamorro A, Cobo E, et al. Thrombectomy within 8 hours after symptom onset in ischemic stroke. N Engl J Med. 2015;372(24):2296-2306.

9. Saver JL, Goyal M, Bonafe A, et al. Stent-retriever thrombectomy after intravenous t-PA vs. t-PA alone in stroke. N Engl J Med. 2015;372(24):2285-2295.

10. Asimos AW, Ward S, Brice JH, Rosamond WD, Goldstein LB, Studnek J. Out-of-hospital stroke screen accuracy in a state with an emergency medical services protocol for routing patients to acute stroke centers. Ann Emerg Med. 2014;64(5):509-515.

11. Oostema JA, Konen J, Chassee T, Nasiri M, Reeves MJ. Clinical predictors of accurate prehospital stroke recognition. Stroke. 2015;46(6):1513-1517.

12. Gupta R, Manuel M, Owada K, et al. Severe hemiparesis as a prehospital tool to triage stroke severity: A pilot study to assess diagnostic accuracy and treatment times. J Neurointerv Surg. 2015.

13. Katz BS, McMullan JT, Sucharew H, Adeoye O, Broderick JP. Design and validation of a prehospital scale to predict stroke severity: Cincinnati prehospital stroke severity scale. Stroke. 2015;46(6):1508-1512.

14. Perez de la Ossa N, Carrera D, Gorchs M, et al. Design and validation of a prehospital stroke scale to predict large arterial occlusion: The rapid arterial occlusion evaluation scale. Stroke. 2014;45(1):87-91.

15. Prabhakaran S, Ward E, John S, et al. Transfer delay is a major factor limiting the use of intra-arterial treatment in acute ischemic stroke. Stroke. 2011;42(6):1626-1630.

16. Lima FO, Silva GS, Furie KL, et al. Field Assessment Stroke Triage for Emergency Destination: A Simple and Accurate Prehospital Scale to Detect Large Vessel Occlusion Strokes. Stroke. 2016 Jun 30

EMS MEd Editor: Maia Dorsett

How the books we read inspire change in our EMS world -- A Fresh Perspective

Melody Glenn, MD

One by one, people start to arrive at Greasebox, a local diner in Oakland, CA, for our inaugural multidisciplinary book club session.  Only a few of the faces are familiar to me -- my colleagues in emergency medicine and EMS, but the rest introduce themselves as students and practitioners working in sociology and public health. I am not sure if they were attracted by our objective -- to discuss issues loosely related to EMS from a multifaceted approach -- or that the author, Seth Holmes MD PhD, of our first book, Fresh Fruit, Broken Bodies, was here to provide his own personal insights to our bookclub.  

In his book, Dr. Holmes delves into a time between his medical school and residency, when he lived and worked with a group of migrant farmworkers, beginning with their dangerous journey across the US-Mexico border. Although he is detained in an Arizona Jail, he continues forward. He follows his adoptive family to various farms along the West Coast, living in substandard living conditions and developing chronic pains from hours in the fields. Why would a young physician want to subject himself to living a life in destitution, danger, and hard-labor? For his anthropology fieldwork, Dr. Holmes’ was committed to observing and recording the health and socioeconomic issues related to a population that is largely undocumented and thus uninsured.  As a result, almost all migrant workers find it difficult to access many American medical services outside of primary care clinics, emergency departments, and Emergency Medical Services (EMS).    

Their jobs and living conditions expose them to a high burden of illness and trauma. Agricultural workers have a fatality rate five times that of all workers, and increased rates of nonfatal injuries, musculoskeletal pain, heart disease, cancer, stillbirth, and congenital birth defects. Their children have high rates of malnutrition, vision problems, dental problems, anemia, and lead poisoning.  Specifically,  Holmes uses three case studies -- Albelino’s knee, Crescencio’s headaches, and Bernado’s stomach pains -- to clearly demonstrate how our medical system fails this population because we don’t recognize the environment they live in or the root causes of their pathology. The medical system, and their physicians, failed them.

However, as Holmes was not yet a practicing physician at the time of writing his book, his analysis sometimes feels too disconnected from the realities of clinical constraints and modern healthcare. Even if we identify the structural factors causing our patients’ illnesses, we, EMS providers and EM physicians, do not have the tools to solve them.  In my 15-minute emergency department visit, I can’t arrange for fair working conditions or safe housing.  It is even more constrained in the prehospital world.  As emergency providers, what can we really do?

In response, Dr. Holmes refers us to a paper that he wrote with Phillippe Bourgois titled, “Structural Vulnerability: Operationalizing the Concept to Address Health Disparities in Clinical Care,” which included a vulnerability assessment tool that can be utilized in our medical assessments.  He also recommended including our patients’ barriers to care in our patient’s H&P, even if we cannot directly fix them, so that they become a formalized part of the patient narrative for other providers to see and incorporate. Lastly, if we see certain issues come up over and over again in multiple patients’ assessments, we can work with local advocacy and policy groups to affect large-scale change.  

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The next week, we tried to put these words into action; an EM resident from the book club used the vulnerability assessment tool during a clinical shift. He noticed that although it took only 35 seconds to read out the questions, the answers took significantly more time. He also did not feel qualified to address their needs.  Instead of having the physician ask the questions on the assessment tool, perhaps there could be a health coach on-staff in order to screen high-risk patients and integrate local social service organizations into the ED milieu.

And that’s when it hit me...maybe there is a role for EMS in this whole complicated issue.  We know that  paramedics actually meet patients where they are -- whether that is the street or their home -- and have the unique ability to see first hand some of the structural barriers to effective medical treatment that patients might face, such as homelessness, polysubstance abuse, lack of insurance, and lack of a social support network.   As a result, I’m working with local partners to incorporate aspects of the structural vulnerability assessment tool into the ePCR so that paramedics have a way to catch patients that they deem high risk of failing medical treatment because of these barriers. For example, when you make your 5th call on that patient living in a dirty Single Room Occupancy (SRO), who is lying in a urine-soaked mattress with a half-drank bottle of vodka at his bedside -- are you surprised that he is again suffering from a CHF exacerbation? If a patient scores high on the prehospital screening tool, they can be referred to a community paramedicine initiative.

Overall, Dr. Holmes’ book Fresh Fruit, Broken Bodies is a solid narrative that takes you through a personal journey of the hardships experienced by our migrant workers, illuminating many of the structural issues that get in the way of their health. As the book’s success weighs heavy on its thoughtful content and sociologic theory, don’t expect it read like a page-turning novel. I believe that chapters 1, 4, and 5 have the most relevance to healthcare providers, and recommend you read them in order to deepen your understanding of the barriers that this population faces. Even if you do not work directly with undocumented people or farmworkers, you will come away with a new perspective that can improve your patient care.

Next book: Five Days at Memorial by Sheri Fink

Five Days at Memorial is the Pulitzer Prize winning work by Sheri Fink, New York Times reporter and physician, about a hospital that faced difficult life-and-death decisions during Hurricane Katrina.

When: January 5, 2016, 6-8 pm Pacific

How to participate: Share thoughts and questions below, or tweet them live to @MGlennEM during the event!

If you want to listen to a great podcast to get you excited, check out the radiolab episode!

Now Is the Age of EMS: It is Time to Revolutionize Our Practice

David K. Tan, M.D.

            Growing up, one of my favorite TV shows was “Emergency!”  I suspect many of our readers with a few grey hairs share my fond memories of watching Johnny and Roy gallantly saving lives every week while receiving sage advice from Dr. Brackett and Dr. Early when they brought the patients to Rampart ER.  It is fascinating to watch the portrayal of the early paramedics and what was necessary to become the first physician surrogates during the birth of EMS.  Training was a few weeks long, online medical control was required to defibrillate VF patients, every IV started in the field required permission as well as a 24-hour follow-up report, and an EOA was considered their advanced airway. 

            Fast forward to today, and look at how times have changed!  We now expect paramedics to interpret Sgarbossa’s criteria on a 12-lead EKG and, in some locales, initiate thrombolytic therapy for it, perform surgical crics, calculate cardioactive pharmaceutical drip rates, and engage in community paramedicine as part of the continuum of medical care.  EMS no longer merely brings patients to health care.  EMS is health care.    We continually pile more and more expectations onto EMTs as well as paramedics, yet we still treat the profession as a vocational tech skill as opposed to a practice of Medicine.   Paramedicine is not skilled labor.  It is a medical practice deserving of the requisite training and education worthy of the trust that citizens place in our abilities and, more importantly, our aptitude for decision-making and critical thinking.  Such capabilities require an entirely new paradigm in EMS education, yet if anyone dares mention that paramedic licensure should be via a college degree pathway instead of a “certificate,” prepare for an onslaught of naysayers! 

            Something else that struck me about Johnny and Roy is that they had a personal relationship with their medical control physicians.  Dr. Brackett did not abrogate his responsibility to teach and mentor his medics to a staff member.  He spent time with them, taught them his approach to patient assessment, gave feedback to the crew, and imparted his sense of the sacred trust between a caregiver and the patient.  Merely by the tone of their voice over the radio, either party instinctively knew if something was awry or if a patient was going to be particularly ill or a situation particularly difficult.  EMS Physicians must find time to break away from the desk and jump on the box or the apparatus, respond unannounced on scenes as a resource and teacher, and spend time in the classroom imparting knowledge impossible to glean from books. 

            As such EMS agencies must recognize that EMS, as a practice of Medicine, requires a compensated physician, ideally board-certified in EMS Medicine, with the requisite time and infrastructure to realize the new reality of this unique practice of Medicine.  Government, from local to state, must support medical oversight including having a functional state EMS office and a state EMS Medical Director. 

            Now is the most exciting time to be an EMS provider in the age of Mobile Integrated Healthcare, recognition by the proverbial House of Medicine as a bona fide subspecialty, and the growth of evidence-based protocols and practice where EMS can actually influence hospital policy.  It is a quantum leap from where Johnny and Roy started, and we now must begin treating this new frontier with a new vision by demanding more from ourselves and each other. 

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Good Care Starts Early: Pre-Hospital Lung Protective Ventilation

Daniel Kolinsky MD, Nicholas M Mohr, MD MS & Brian M Fuller, MD, MSCI

Case Scenario

‘Not again,’ you think to yourself as you listen to the dispatch report. “Call for inter-hospital transport. The patient is a 58 year-old male with a recent diagnosis of pneumonia, in the ED with acute respiratory failure, and is now intubated. Needs transport to the ICU.” This presentation is all too familiar. You remember transporting a similar patient two hours ago. How could you forget? He was hypoxic in the 80’s from his pneumonia.

On arrival to the ED, you get report from the nurses. During sign out you notice that the patient’s ventilator settings are different, specifically the tidal volume is substantially higher than the previous patient’s. You remember that lung-protective ventilation improves outcome in patients with ARDS. You wonder if the same lung-protective strategy should be used in patients at risk for ARDS?

Clinical Question

Does the early use of lung-protective ventilation reduce the incidence of ARDS?

Literature Review

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Pre-hospital care of the critically ill and injured patient often requires airway management and subsequent mechanical ventilation. Modern transport ventilators can support critically ill patients across the spectrum of illness severity, and also provide more reliable tidal volume and respiratory rates than manual bag-valve positive pressure ventilation. [1] Furthermore, they also free up the advanced care medic to perform other necessary patient care activities. [2]

Although portable mechanical ventilators have advanced critical care transport capabilities, they are not without risk. Ventilator associated lung injury (VALI) is a general term that refers to how a ventilator can propagate injury in already damaged lungs, or initiate injury in at-risk lungs. [3] Lung-protective ventilation aims to mitigate VALI by reducing the mechanical power applied to the lungs. [4] In patients with established ARDS, lung-protective ventilation with low tidal volume and effective PEEP is standard of care. [5-6] There is also a growing body of evidence from critically ill patients in the ICU and operating room demonstrating that low tidal volume ventilation [6-8 mL/kg predicted ideal body weight (PBW)] is associated with improved outcomes in mechanically ventilated patients without ARDS. [7-12] Although the data are not definitive, the current body of evidence suggests that using lung-protective ventilation strategies can mitigate VALI and prevent progression to ARDS.

Pre-hospital transport and the emergency department (ED) are the common entry points into the hospital for critically ill patients, yet only recently has research been devoted to mechanical ventilation in these arenas. Low tidal volume ventilation initiated in the ED is more likely to be continued in the ICU. [13-14] Additionally, it has been demonstrated that the mechanical ventilation strategy started in the pre-hospital setting is often continued in the ED and in the ICU.15 Together, these studies demonstrate that “ventilator inertia” is real and reinforce the importance of initiating lung protective ventilator strategies from the outset. Unfortunately, compliance with lung protective ventilation strategies in the pre-hospital setting (13%) and ED (range 27.1%-55.7%) leaves much room for improvement. [13-15]

As more studies show that earlier diagnoses with commensurate time-sensitive interventions for the critically ill improves outcomes, pre-hospital personnel will be expected to implement these new standards into practice. [16] Among these interventions, ventilator management is paramount as mechanical ventilation is one of the most common indications for intensive care. [17-18] Providers transporting these patients in the post-intubation period must think about the potential for VALI, as ARDS develops early in the course of critical illness. [12]

Setting the Ventilator

In order to determine the appropriate tidal volume for lung protective ventilation, one needs to know the patient’s gender and height in order to calculate the PBW. PBW can then be derived from a table for low tidal volume ventilation.

Other ventilator parameters to monitor when using lung protective ventilation are positive end-expiratory pressure (PEEP) and the plateau pressure. PEEP can be used to keep diseased alveoli open and limit physiologic shunting thus reducing hypoxemia. Setting the PEEP to 5 cm H2O and titrating PEEP and fraction of inspired oxygen (FiO2) combinations using a PEEP table is a simple way to maintain alveolar recruitment and limit derecruitment injury (i.e. atelectrauma). Targeting oxygen saturations of 88% or greater can limit the dangers of hyperoxia as well.[19] Additionally, maintaining plateau pressures less than 30 cm H2O helps to limit alveolar stretch.

Take Home Points

Acknowledgement that the pre-hospital period is part of the continuum of critical care has led to a focus on implementing best care practices early. In the intubated patient, this includes ventilator management and institution of lung-protective ventilation. Currently, there is a growing body of evidence for using lung-protective ventilation to reduce VALI and to prevent to ARDS. Several large studies testing prophylactic lung protective ventilation are underway. [20-21] Their results will provide further insight into the use of early lung-protective ventilation to improve outcomes.

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References

1.     Gervais HW, Eberle B, Konietzke D, Hennes HJ, Dick W, “Comparison of blood gases of ventilated patients during transport”. Critical Care Medicine 1987;15:761-763.

2.     Weiss, Steven J., et al. "Automatic Transport Ventilator Versus Bag Valve In The EMS Setting: A Prospective, Randomized Trial." Southern Medical Journal 98.10 (2005): 970-976.

3.     Slutsky AS, Ranieri VM. Ventilator-induced lung injury. N Engl J Med. 2013 Nov 28;369(22):2126-36.

4.     Gattinoni L, Tonetti T, Cressoni M, Cadringher P, Herrmann P, Moerer O, Protti A, Gotti M, Chiurazzi C, Carlesso E, Chiumello D, Quintel M. Ventilator-related causes of lung injury: the mechanical power. Intensive Care Med. 2016 Oct;42(10):1567-75.

5.     The Acute Respiratory Distress Syndrome Network: Ventilation with lower tidal volumes as compared with traditional tidal volumes for acute lung injury and the acute respiratory distress syndrome. N Engl J Med 2000, 342:1301-1308.

6.     Putensen C, Theuerkauf N, Zinserling J, Wrigge H, Pelosi P. Meta-analysis: ventilation strategies and outcomes of the acute respiratory distress syndrome and acute lung injury. Ann Intern Med. 2009;151:566–76.

7.     Determann RM, Royakkers A, Wolthuis EK, Vlaar AP, Choi G, Paulus F, et al. Ventilation with lower tidal volumes as compared with conventional tidal volumes for patients without acute lung injury: a preventive randomized controlled trial. Crit Care 2010;14:R1.

8.     Mascia L, Pasero D, Slutsky AS, Arguis MJ, Berardino M, Grasso S, Munari M, Boifava S, Cornara G, Della Corte F, Vivaldi N, Malacarne P, Del Gaudio P, Livigni S, Zavala E, Filippini C, Martin EL, Donadio PP, Mastromauro I, Ranieri VM. Effect of a lung protective strategy for organ donors on eligibility and availability of lungs for transplantation: a randomized controlled trial. JAMA. 2010 Dec 15;304(23):2620-7.

9.     Futier E, Constantin JM, Paugam-Burtz C, Pascal J, Eurin M, Neuschwander A, et al. A trial of intraoperative low-tidal-volume ventilation in abdominal surgery. N Engl J Med 2013;369:428–37.

10. Serpa Neto A, Cardoso SO, Manetta JA, et al. Association between use of lung- protective ventilation with lower tidal volumes and clinical outcomes among patients without acute respiratory dis- tress syndrome: a meta-analysis. JAMA. 2012;308(16):1651-1659.

11. Serpa Neto A, Simonis FD, Barbas CS,et al. Association between tidal volume size, duration of ventilation, and sedation needs in patients without acute respi- ratory distress syndrome: an individual patient data meta-analysis. Intensive Care Med. 2014;40(7):950-970.

12. Fuller BM, Mohr NM, Drewry AM, Carpenter CR. Lower tidal volume at initiation of mechanical ventilation may reduce progression to acute respiratory distress syndrome: a systematic review. Crit Care. 2013;17(1):R11.

13. Fuller BM, Mohr NM, Miller CN, Deitchman AR, Levine BJ, Castagno N, Hassebroek EC, Dhedhi A, Scott-Wittenborn N, Grace E, Lehew C, Kollef MH. Mechanical Ventilation and ARDS in the ED: A Multicenter, Observational, Prospective, Cross-sectional Study. Chest. 2015 Aug;148(2):365-74.

14. Fuller BM, Mohr NM, Dettmer M, Kennedy S, Cullison K, Bavolek R, Rathert N, McCammon C. Mechanical ventilation and acute lung injury in emergency department patients with severe sepsis and septic shock: an observational study. Acad Emerg Med. 2013 Jul;20(7):659-69.

15. Stoltze AJ, Wong TS, Harland KK, Ahmed A, Fuller BM, Mohr NM. Prehospital tidal volume influences hospital tidal volume: A cohort study.J Crit Care. 2015 Jun;30(3):495-501.

16. Seymour CW, Rea TD, Kahn JM, Walkey AJ, Yealy DM, Angus DC. Severe sepsis in pre-hospital emergency care: analysis of incidence, care, and outcome. Am J Respir Crit Care Med 2012;186:1264–71.

17. Esteban A, Anzueto A, Frutos F, et al; Mechanical Ventilation International Study Group. Characteristics and outcomes in adult patients receiving mechanical ventilation: a 28-day interna- tional study. JAMA. 2002;287(3):345-355.

18. Needham DM, Bronskill SE, Calinawan JR, Sibbald WJ, Pronovost PJ, Laupacis A. Projected incidence of mechanical ventilation in Ontario to 2026: preparing for the aging baby boomers. Crit Care Med. 2005;33(3):574-579.

19. Girardis M, Busani S, Damiani E, Donati A, Rinaldi L, Marudi A, Morelli A, Antonelli M, Singer M. Effect of Conservative vs Conventional Oxygen Therapy on Mortality Among Patients in an Intensive Care Unit: The Oxygen-ICU Randomized Clinical Trial. JAMA. 2016 Oct 5.

20. Fuller BM, Ferguson I, Mohr NM, Stephens RJ, Briscoe CC, Kolomiets AA, Hotchkiss RS, Kollef MH. Lung-protective ventilation initiated in the emergency department (LOV-ED): a study protocol for a quasi-experimental, before-after trial aimed at reducing pulmonary complications. BMJ Open. 2016 Apr 11;6(4):e010991.

21. Simonis FD, Binnekade JM, Braber A, Gelissen HP, Heidt J, Horn J, Innemee G, de Jonge E, Juffermans NP, Spronk PE, Steuten LM, Tuinman PR, Vriends M, de Vreede G, de Wilde RB, Serpa Neto A, Gama de Abreu M, Pelosi P, Schultz MJ. PReVENT--protective ventilation in patients without ARDS at start of ventilation: study protocol for a randomized controlled trial. Trials. 2015 May 24;16:226.