Airway Management Research Update: What Works
Nothing against my fellow paramedics, but ED docs who teach, perform, research, and write about endotracheal intubation (ETI) are great sources of best airway practices for EMS personnel. We’re on the same team when it comes to minimizing hypoxia in the acutely ill. That’s why Airway World’s quarterly webinars should be on the calendars of every clinician who wants to be a better airway manager.
RSI or DSI?
Calvin Brown III, MD, attending physician at Boston’s Brigham and Women’s Hospital, began June’s session with a paper about minimizing O2 desaturation during prehospital ETI attempts. Rather than focusing on a specific intervention, the study compares two pre-intubation bundles of care: 1) ketamine, paralytics, and apneic oxygenation at maximum flow via non-rebreather mask and 2) ketamine, delayed paralytics, head elevation, and apneic oxygenation via nasal cannula. Hypoxia in the latter group was only 4%, compared to 44% in the former. Stated another way, conventional rapid-sequence intubation seemed much less effective than delayed-sequence intubation, although the relative values of each bundle’s components weren’t quantified.
SUX ROCs? ROC SUX?
Asking anesthesiologists whether they prefer succinylcholine (SUX) or rocuronium (ROC) for peri-intubation neuromuscular blockade is like polling paramedics about Miller blades versus Macs. Opinions are likely to be unscientific and heavily skewed toward personal experience.
SUX and ROC have different characteristics, contraindications, and side effects, but according to 2016 research they’re equally effective during intubation. That’s important to know because some EMS systems carry both meds.
First-attempt success (FAS) using either was 87%, while overall success was 99%, with a 15% chance of adverse events. Case-specific risk factors aside, whether to go with ROC or SUX is, as Brown pointed out, “not worth arguing over.”
Out of Style(ts)
Back in 1994 I didn’t just learn to intubate with a stylet; I learned not to intubate without one, and for good reason: Coaxing a floppy tube into an anterior airway was not something any of us were eager to try.
Now that we’re in the era of ETT introducers known as bougies, I suspect stylets will soon be as scarce as defibrillation paddles. Such near-extinction is justified according to a 2016–17 study presented by Brian Driver, MD, of Hennepin County (Minn.) Medical Center. Among 757 patients undergoing ETI, FAS was 98% using bougies and 87% with stylets. Eighty-five percent in the bougie group and 77% in the stylet group didn’t experience hypoxia.
For 380 patients with difficult airways, FAS was 96% with bougies and 82% without. Hypoxia was avoided in 82% and 69% of ETI attempts, respectively.
The take-home message about bougies? They’re cheap and easy to use, they don’t block your view of the oropharynx as much as a tube, and they should either replace stylets or be readily available as alternatives.
HEAVEN Can Wait
I’m not a big fan of mnemonics. It takes me too long to remember what each word or letter stands for, which kind of defeats the purpose of memory aids.
Take HEAVEN. It’s an acronym that highlights the following characteristics of difficult airways: hypoxia, extremes of size, anatomic abnormalities, vomit/blood/fluid, exsanguination, and neck mobility. However, a 2017 study showed HEAVEN has mostly negative predictive value—i.e., HEAVEN is best at identifying people with unremarkable airways and less helpful when patients start meeting its criteria.
You can learn more about the HEAVEN paradox and access all of Airway World’s quarterly updates at http://www.airwayworld.com/webinars/.
Mike Rubin is a paramedic in Nashville and a member of EMS World’s editorial advisory board. Contact him at email@example.com.