The Australian New Zealand ED airway registry (ANZEDAR) includes 43 ED’s that prospectively submit data on patients they intubate. It has provided a wealth of information on how we manage airways.
This study looked at patients who got apnoeic oxygenation (ApOx) during RSI vs. those that did not. (ApOx was defined as patients getting up to 15L of oxygen via a nasal cannula.) They excluded patients intubated during cardiac arrest and those that got BVM or NIV during the apnoeic period.
The primary outcome was rates of desaturation to <93%.
1669 (66%) patients got ApOx and 850 (33%) did not. Desaturation occurred in 10% of the ApOx group vs. 13% in the other group.
Maybe… maybe not…
This was not a randomized trial. As such, there could have been confounding factors or that led to the differences observed. (But to be fair, I would imagine that doctor would have been more likely to provide ApOx in those patients that they were worried might desaturate. Therefore, making the ApOx group look potentially worse. But perhaps I’m wrong…)
This was a study of registry data. Unfortunately, this data is often of poor quality. It’s possible we may have a “garbage in, garbage out” phenomenon. Intubation is often an anxiety provoking procedure where doctors get task focused. They may have not really been aware of how low the saturations dropped. Ideally, one would get the data from a research assistant who is tasked to collect accurate data at the time.
Desaturation is not really a patient-oriented outcome. Transient hypoxemia probably causes no harm in most patients. Ideally, we would look at more important outcomes involving real patient morbidity and mortality. But good luck powering such a study!
If ApOx doesn’t really change any important patient outcomes than arguably it may be one extra step that distracts us from getting the job done. In times of high stress, we need to keep our processes as simple as possible.
The debate continues…
Perera A, Alkhouri H, Fogg T, et al. Apnoeic oxygenation was associated with decreased desaturation rates during rapid sequence intubation in multiple Australian and New Zealand emergency departments. Emerg Med J 2021;38:118-124. [Link to article]