Ostermayer DG, Gausche-Hill M. Supraglottic airways: The history and current state of prehospital airway adjuncts. Prehosp Emerg Care. 2014;18(1):106–115.
The EMS Science
This review paper, written by two noted researchers in the area of prehospital airway management, provides an in-depth review of the history of supraglottic airway devices. Ostermayer and Gaushce-Hill, both from the Department of Emergency Medicine at Harbor-UCLA Medical Center in Torrance, Calif., clearly lay out the existing science both for and against the use of supraglottic airways, or blind insertion airway devices (BIAD).
This paper is not an editorial comment on the various available devices but is instead a comprehensive review of the published literature that not only provides evidence for each device’s efficacy but data that compares several of the devices to each other.
Additionally, the authors provide a literature review comparing supraglottic airways to endotracheal intubation.
Doc Keith Wesley Comments:
EMTs and paramedics frequently ask me why I’m such an advocate for the use of supraglottic airways. My answer is simple: EMS providers don’t receive sufficient opportunities for endotracheal intubation during their initial training and ongoing clinical practice to maintain competency in this procedure.
Several organizations, including the American Heart Association and Committee on Accreditation of EMS Programs, have stated that providers need at least 12–25 intubations to reach competency and an unknown number to maintain it.
As the literature review in this paper makes clear, BIADs are easier and take less time to insert than endotracheal intubation. Additionally, they cause less interruption in chest compression when used during cardiac arrest.
Some of the old-timers remember the Esophageal Obturator, a device I quickly dubbed a “tool of the devil” because of all its associated complications. The laryngeal mask airway (LMA) was the first BIAD on the market but was only seen in Europe and Australia. In the U.S. the Combitube was the first BIAD to gain widespread use, but after reading this paper, I wonder why. The LMA appears to be far superior to the Combitube and this paper should make you think twice about continuing to use the Combitube rather than some other device.
Rapid sequence intubation (RSI) continues to be controversial in many services and I suspect it’s the concern that providers aren’t competent in intubation and therefore medical directors are reluctant to add induction agents and paralytics to their agency’s scope of practice.
This paper provides strength to the argument that instead of RSI we should be considering rapid sequence airway (RSA) where the supraglottic airway is the primary airway device instead of the entrotacheal tube. My service calls it drug-facilitated airway management, and since its adoption, the BIAD has become our primary device of choice rather than a secondary or “rescue” airway device.
Medic Karen Wesley Comments:
Changes in EMS practice are primarily based on science—at least they should be. This study is comprehensive in presenting airway tools available for prehospital use.
But the science will change again as we discover new devices and their effect on patient outcomes. And our protocols and equipment will change again. That’s the great part of research and publication. We can’t all try out every airway device in the prehospital setting, so it’s important for all of us to check out the science behind the equipment we currently use and the equipment that maybe we should be using.
Studies clearly show that time “off the chest” must be minimized for optimal outcomes in cardiac arrest patients. As Doc points out, we’re at a disadvantage with having necessary time for patient movement, etc.
Minimizing the apnea period for placement of a secure airway during any resuscitation is crucial. This study confirms the supraglottic airways with BIADs meet that need. It isn’t a matter of having endotracheal intubation removed from our scope of practice—it’s what’s right for the patient.
We have machines that evaluate our CPR and EtCO2 monitoring, in real time. A lot can happen while you’re focused on a set of vocal cords. It’s time to simplify our procedures, hold fewer tools in our hands, employ critical thinking, and keep our eyes on the big picture.