Written by Nick Zelt
Spoon Feed
There was no benefit to using high-flow nasal cannula (HFNC) at 60L/min vs regular NC at 15L/min for pre- and apneic oxygenation during emergency department (ED) intubations.
Why does this matter?
Intubation is a dangerous time; we’ve taken away our patient’s ability to breathe on their own. Until we get the tube in the right place, we are relying on the patient’s oxygen reserves. In order to maximize and expand those reserves, some advocate for using HFNC during pre-oxygenation and even during the intubation itself for apneic oxygenation. This practice is supported by RCT level data in the ICU. However, the question remains if HFNC would be better than simply using regular nasal cannula (NC) for intubations done in the ED.
Nose-breathers rejoice
This is a randomized controlled trial of 190 adult ED patients assigned 1:1 to oxygenation before and during intubation with either HFNC at 60L/min or regular NC at 15L/min. The primary outcome was lowest SpO2 during the first intubation attempt. Most intubations were done with a C-MAC video laryngoscope.
There was no significant difference in the primary outcome; a median SpO2 of 100% was seen in both groups. During subgroup analysis of the lowest quartile of SpO2, the HFNC group showed significantly higher oxygen saturations, which suggests a larger study might detect a difference. There were no significant differences in the secondary outcomes, though safe apnea time was higher in the HFNC group (11min) compared with NC (7min).
There are several limitations to this study. The patients were not consecutively enrolled due to the pragmatic approach to enrolment, where providers could be too busy managing the resuscitation to include the patient in the study. This led to 42% of intubations being done for neurological conditions (i.e. ICH, SDH, SAH, seizure) and cardiorespiratory problems perhaps being underrepresented. Interestingly, the authors claimed that a non-rebreather mask was equivalent to BVM for pre-oxygenation, though they only cite studies in healthy volunteers. Additionally, no patient-centered outcomes were measured.
Given how easy it is to leave a regular nasal cannula on my patient during intubation, there appears to be only potential benefit to using this for apneic oxygenation. But without a clear difference favouring HFNC, I don’t think this is worth the trouble.
Source
Pre- and apnoeic high-flow oxygenation for rapid sequence intubation in the emergency department (the Pre-AeRATE trial): A multicentre randomised controlled trial. Ann Acad Med Singap. 2022 Mar;51(3):149-160. doi: 10.47102/annals-acadmedsg.2021407.
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