Airway Management Research Update: Bedside Best Practices

As supraglottic airways proliferate and endotracheal intubation (ETI) becomes less routine prehospitally, paramedics have a decision to make: Accept the erosion of proficiency accompanying rarely practiced skills or double down on dedication to maintain ETI currency. Those who choose the latter will find September’s Airway World webinar helpful.

The topics—predicting difficult airways, preoxygenation, peri-intubation hypotension, and video laryngoscopy (VL)—are tailored to hospital settings, but curious and astute EMS personnel should have no trouble picking out the applicable pearls.

LEON Is No LEMON

LEMON is an airway-assessment acronym that hasn’t made its way into mainstream EMS. It works like this:

• Look externally (subjective impressions);
• Evaluate (objective impressions);
• Mallampati score;
• Obstruction/obesity;
• Neck mobility.

The Mallampati score, a visual impression of oropharyngeal obstacles, is the least familiar LEMON component to most EMS providers. No problem—delete it. Now you have LEON—still a powerful predictor of difficult airways according to a 2016 South Korean study. Not surprisingly, neck mobility—or the lack of it—was most closely correlated to ease of ETI among trauma patients. Caregivers who used VL instead of direct laryngoscopy (DL) had less trouble intubating collared patients.

PPV + ApOx = OK

Suppose you want to preoxygenate your soon-to-be-intubated patient via positive-pressure ventilation and employ apneic oxygenation during ETI. Do you have to switch from one to the other?

According to a 2018 study, you can use both O2-delivery devices simultaneously. Go ahead and attach that nasal cannula before preoxygenation; the plastic hose won’t compromise the PPV mask seal.

Physiology First

So much of the emphasis on prehospital airway management is to avoid delay; to recognize when prompt, if not rapid, ETI is a lifesaving intervention. But what about those patients whose perfusion is already so compromised, by-the-book RSI starts to look like a bad choice?

A retrospective review of 1,087 adult patients by South Korean researchers confirmed what the American Heart Association implied when it substituted CAB for ABC: that treatment of profound hypotension is often a higher priority than definitive airway management. Fluids, pressors, and cardiostable induction agents such as etomidate and ketamine are prehospital options in many EMS systems. If etomidate is your only sedative, it might be better to skip it in the setting of refractory shock or administer a reduced dose.

Ketamine is occasionally useful in supporting blood pressure through indirect stimulation of catecholamines. Of course, that assumes the patient still has catecholamine reserves.

Let’s Go to the Video

I’ve written so much during the past three years about the compelling evidence for VL over DL, I feel like there’s not much more to say. Let me just stress one important point from the August issue of Annals of Intensive Care: Authors led by Moon Seong Baek of South Korea’s University of Ulsan compared first-attempt ETI success (FAS) by rapid-response teams using VL vs. DL on 958 patients at a teaching hospital. FAS was 79% with VL and 59% with DL. That’s a difference worth noting.

To those of you who aren’t familiar with VL, what I’m presenting is by no means the extent of research on that device. Study the literature, and you’ll see why video laryngoscopy is becoming as mainstream as 12-lead EKGs were 15 years ago. If your agency wants to rely solely on DL, suggest it can save even more money by dusting off those LIFEPAK 10s.

You can access all of Airway World’s quarterly updates at https://www.airwayworld.com/webinars/.

Mike Rubin is a paramedic in Nashville and a member of EMS World’s editorial advisory board. Contact him at mgr22@prodigy.net.