Guest Post - Perhaps Paramedics Should NOT Intubate!

What if we're wrong? What if the "gold standard" for airway management is not approriate for EMS personnel? Even though many of us spent  untold hours training to perform ET intubation, and have felt justifiable pride in performing this skill well, is it possible that our efforts have been (ahem) misplaced?

This is a guest post by Ben Dowdy, NRP, exploring this unpopular position, reevaluating the opposite perspective. This is part of the inaugural "What-if-We’re-Wrong-a-Thon" organized by Brandon Oto of EMS Basics fame (and soon-to-be lead author in a Very Important Journal).

The continued role of endotracheal intubation as a standard prehospital skill continues to be debated, sometimes hotly.  I’m going to present an argument against prehospital endotracheal intubation.

Aspiration Prevention

Proponents of endotracheal intubation often use the argument that ET intubation protects the airway from aspiration.  But how true is such a claim?  Multiple studies of emergency airway management list aspiration as an infrequent complication ^1,2, only occurring 2.8-3.5% of the time.  A study of prehospital RSI³ found that pre-intubation evidence of aspiration was noticed in a significant number of patients, but only one incidence of peri-intubation aspiration was recorded, and no instances of post-intubation aspiration were reported.

What to make of this?  Aspiration pneumonia is a serious diagnosis, conferring an adjusted 2.3 odds ratio in favor of mortality⁴.  But for the majority of patients having their airway managed in the prehospital field, if aspiration is going to occur, it’s extremely likely that it happens prior to EMS providers arriving and managing the airway.  A prehospital ET tube prevents aspiration very uncommonly.

No Mortality Benefit

As EMS evolves, we’re constantly being challenged to ensure that our treatments and procedures have meaningful, patient-oriented outcomes.  As I heard it referred to early in my paramedic career, “we should be doing things for patients, not to them.”  For prehospital intubation, unfortunately, that does not appear to be the case.  The available literature investigating prehospital intubation’s effects on mortality^5-9 overwhelmingly show that if trauma patients are alive when they’re intubated in the field, their chance of dying just increased.  For patients who are already in cardiac arrest, evidence is conflicting as to whether ANY advanced airway management improves mortality, and even then the champion between supraglottic airways and endotracheal intubation varies with almost every new study that comes out.

Can EMS Education Programs Assess Competency in Intubation?

Initial requirements for intubation training in EMS used to be laughable under the National Standard Curriculum; 5 intubations was all you needed, compared with 50+ in medical schools.  The National EMS Education Standards thankfully replaced this with the more blanket term of “demonstrating competency” during providers’ initial training programs, allowing educational institutions to set the bar higher to ensure that new paramedics could competently intubate patients.  However, this higher standard has created difficulties.  A series of surveys¹⁰ distributed by the Committee for Accreditation of EMS Programs (CoAEMSP) found that 53% of programs have difficulty obtaining access to ORs for students to practice; 81% use high-fidelity simulators to determine competency and 90.7% urged CoAEMSP to allow these simulators as a means of demonstrating competency.  In others words, most EMS education institutions can’t ensure that their paramedic graduates will ever intubate an actual person, even a stable one undergoing elective surgery, prior to getting their certification or licensure.  To add even greater concern, the available airway mannequins commonly used in EMS airway training (including the ones that most programs want to use to “prove” competency) correlate extremely poorly with airway measurements of actual people¹¹.

Summary

Endotracheal intubation is a skill that’s difficult to master; it takes a lot of realistic practice during initial education and at frequent intervals afterwards to be able to succeed in prehospital settings.  Our education institutions can’t guarantee that providers entering the field can competently intubate patients.  The common argument of “aspiration protection” is a false one; aspiration doesn’t occur very often at all during emergency airway management, it occurs before we ever show up.  When we intubate people, their mortality rate increases.  It’s time to stop using endotracheal intubation as a first-line airway management technique until we can prove that we’re doing it for our patients, instead of to them.

References

1.     Thibodeau LG, et al (1997).  “Incidence of Aspiration after Urgent Intubation.”  Am J Emerg Med. 1997 Oct;15(6):562-5.

2.     Martin LD, et al (2011).  “3,423 emergency tracheal intubations at a university hospital: airway outcomes and complications.”  Anesthesiology. 2011 Jan;114(1):42-8.

3.     Vadeboncoeur TF, et al (2006).  “The ability of paramedics to predict aspiration in patients undergoing prehospital rapid sequence intubation.”  J Emerg Med. 2006 Feb;30(2):131-6

4.     Lanspa MJ, et al (2015).  “Characteristics associated with clinician diagnosis of aspiration pneumonia: a descriptive study of afflicted patients and their outcomes.”  J Hosp Med.  2015 Feb; 10(2):90-6.

5.     Evans CC, et al (2013).  “Prehospital non-drug assisted intubation for adult trauma patients with Glasgow Coma Score less than 9.”  Emerg Med J. 2013 Nov;30(11):935-41.

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

7.     Taghavi S, et al (2014).  “Prehospital intubation does not decrease complications in the penetrating trauma patient.”  Am Surg. 2014 Jan;80(1):9-14.

8.     Kempema J, et al (2015).  Prehospital endotracheal intubation vs. extraglottic airway device in blunt trauma.”  Am J Emerg Med. 2015 Apr 29.

9.     Stockinger ZT, McSwain NE Jr. (2004).  “Prehospital endotracheal intubation for trauma does not improve survival over bag-valve-mask ventilation.”  J Trauma. 2004 Mar;56(3):531-6.

10.  Kalish, MA (2013).  “Definition of Airway Competency.”  http://coaemsp.org/Documents/Airway-Competency-Kalish-2013-09.pdf

11.  Schebesta K, et al (2012).  “Degrees of reality: Airway Anatomy of High-fidelity Human Patient Simulators and Airway Trainers.”  Anesthesiology.  2012 June;116(6):1204-9.

Bio: Ben Dowdy B.S., NRP, is a paramedic and EMS educator currently working in northern Idaho.  His past experiences include working as a paramedic, tactical paramedic, and SAR medic in urban, rural, and wilderness areas, including Yellowstone National Park, and teaching EMS topics for a university-based EMS education program, as well as across the US and abroad for Wilderness Medical Associates.

Update: Cyanokit for cardiac arrest in fire victims

I had written about this topic last year, but a recent EM:RAP segment and ensuing Twitter discussion prompted me to revisit the issue. Sadly, there is no new evidence to add to the discussion.  Nonetheless, let's revisit the question: 

If a pulseless patient is pulled from a smoky, burning building, will giving Cyanokit during CPR help?

 

Step 1

1. There is no known “50% ROSC rate” because of Cyanokit.

The four studies looking at this issue are, by design, unable to support any such conclusion. They were case-series, with no controls whatsoever. They gave Cyanokit to a number of people, and some of them lived. However, we have no idea if the “save rate” was better or worse than usual care. These studies show that EMS can administer Cyanokit, but they can’t speak to its effectiveness at all.  As a result, even toxicologists don’t make much of these studies.

Furthermore, most of the “saves” in one study had ROSC before they received the Cyanokit. It isn’t clear in the other studies when the patients received the antidote, and the amount of missing data makes it hard to interpret.

Go read the original studies; the links are at my post Does Cyanokit save lives in cardiac arrest? 

Step 2

2. Meds, in general, don’t increase save rates in cardiac arrest.

Although the AHA teaches a “reversible cause” approach to arrest, this isn’t helpful most of the time. For example, although heroin OD and severe hypoglycemia may cause cardiac arrest, there is no AHA recommendation to give naloxone or dextrose in cardiac arrest. In fact, naloxone use is discouraged.

Same with tPA. An AMI or a PE commonly triggers cardiac arrest, and tPA could theoretically “treat the cause.” But the evidence showed that, overall, it didn’t work during cardiac arrest. True, many of us have tried it once or twice, but not routinely. 

Step 3

3. I’m no EBM diehard, but we have to do better than this!

The evidence for Cyanokit is sort of like the evidence that supported Digibind (for digoxin OD) or fomepizole/Antizol (for methanol/ethylene glycol OD). Neither one of those drugs had a supporting RCT, or even a strong case-control trial. Indeed, the important studies showing their benefit were open-label, and uncontrolled. (E.g. Brent 1999 “Fomepizole for the Treatment of Ethylene Glycol Poisoning,” and Antman 1990 “Treatment of 150 cases of life-threatening digitalis intoxication with digoxin-specific Fab antibody fragments.”). 

However, the low rate of adverse effects, and the strong mechanistic and animal data, along with the difficulty of conducting a true RCT, argued strongly in favor of using these drugs, despite active discussion regarding the costs. So it’s appealing to use a similar argument to support using Cyanokit.

This argument, however, also suggests that recommendations for the routine administration of Cyanokit are very premature. The studies of Digibind and Antizol were of far higher quality than the 3 French and 1 Texas Cyanokit studies. 

For example, both Brent 1999 and Antman 1990 used prospective collection of data (rather than chart review), and both used clear, quantitative criteria for the use of the antidotes. That approach generated high quality data, which could be used to make valid comparisons with historical cohorts. By contrast, the Cyanokit studies are of very low-quality, based on chart reviews with unclear methods, and have plenty of missing data. 

Step 4

4.  Cardiac arrest at fire scene, especially in a firefighter?

It’s probably an MI, and the key issue isn’t getting a miracle drug started, but getting access to the patient to start high-quality CPR, and defibrillating as early as possible. Getting the gear off a “downed” firefighter requires a coordinated team effort, with plenty of practice beforehand.

Step 5

"Pit crew" style CPR has been proven to save lives. Firefighters have been shown to have high rates of cardiac disease, and high rates of on-duty arrests. It's a fact that it's hard to do CPR on someone wearing bunker gear and a SCBA. If your FD isn't drilling for this scenario, an expensive drug isn't going to help. 

The good news about saving a firefighter's life is that it's free and proven - but you have to put in some effort. Check out the Firefighter Down- CPR website for the specifics on how to improve your response. Here's the vid: