Advancing Airway Management: Apneic Nasal Oxygenation

Darren Braude, MD, EMT-P, is a featured speaker at EMS World Expo, November 9–13, in Nashville, TN. Visit EMSWorldExpo.com.

When it comes to EMS airway management, the name of the game—at least in the first 20 minutes—is maintaining oxygenation. This is much more important initially than ventilation, particularly in patients with head injury where hypoxemia can be devastating.

The traditional approach to intubation in the cardiac arrest or crash airway scenario is to pre-oxygenate with bag valve mask (BVM) (the directions often state hyperventilate) and then to keep the intubation attempt short (directions often state for the intubator to hold their own breath) to minimize hypoxemia. The traditional approach to drug-facilitated or rapid sequence intubation (RSI) is to pre-oxygenate with a non-rebreather mask and then monitor the patient’s saturation during the intubation attempt, with the intention of aborting when the saturation drops below a prescribed level—usually 90%. We have new simple strategies available to improve pre-oxygenation and avoid hypoxemia during the intubation itself. Our favorite new strategy at The Difficult Airway Course: EMS is apneic nasal oxygenation.

Apneic nasal oxygenation is a simple technique that can be utilized in virtually every intubation attempt from the cardiac arrest patient to RSI. The idea is to first place a nasal cannula on the patient underneath whatever device is being used for pre-oxygenation (i.e., CPAP mask, BVM, non-rebreather). If there are ample oxygen supplies and outlets, then the nasal cannula can be turned on from the outset; otherwise you can wait until you actually remove the primary oxygen delivery device. In either case, the goal is to have oxygen running through the nose while the intubation is in progress. Most research has focused on low-flows of oxygen (less than or equal to 5 liters) though some experts such as Rich Levitan, MD, and Scott Weingart, MD, recommend 15-liter flows for older pediatric and adult patients. If you are thinking that the patient won’t tolerate such high oxygen flows you would be correct if the patient were awake, but in the context of cardiac arrest, the crash airway or the patient who has been induced for RSI, this is not an issue. Surprisingly, the oxygen will make it to the alveoli without active ventilation and then diffuse passively from the higher concentrations of the alveoli to the lower concentration in the blood.

I have personally adopted this strategy for virtually every intubation I perform—whether it is in the ED or in the field—and have noticed a remarkable decrease in hypoxemia. Of course there are some patients who are so fragile that even apneic nasal oxygenation cannot prevent rapid and severe hypoxemia, but for most patients this is a cheap and simple way to improve patient outcomes.

Darren Braude, MD, EMT-P, is associate professor of emergency medicine and anesthesiology at the University of New Mexico School of Medicine in Albuquerque. He is associate medical director for The Difficult Airway Course: EMS and all EMS programs offered by First Airway, LLC.