Written by Clay Smith
Spoon Feed
Delivery of buccal oxygen as a form of apneic oxygenation was highly effective and safe.
Why does this matter?
There is debate about the effectiveness of high flow nasal cannula as a means of apneic oxygenation. The FELLOW investigators and ENDAO RCT found it did not work. However, multiple other studies found it did. We covered some of the same authors a couple years ago when they published on the efficacy of the buccal oxygenation technique in obese patients.
What’s that taped to my face?
This was a RCT of buccal apneic oxygenation vs sham technique involving 20 patients. They found that when maintaining prolonged laryngoscopy to keep the airway open, the group receiving buccal apneic oxygenation had a median apnea time of 750 seconds (the primary outcome) vs 447 seconds in the sham group. To translate, 750 seconds is 12.5 minutes not breathing and not having desaturation. Tracheal pressures were low, making barotrauma a non-issue. Each minute of apnea time saw an average rise in CO2 by 2.2mmHg/minute. Just one patient in the buccal O2 group had a desat <95% prior to 750 seconds of apnea.
Buccal oxygenation consists of a 3.5mm RAE tube taped on the outside of the left cheek directing a flow of O2 at 10L/min backward toward the trachea. Keep in mind, these patients were preselected as not having a difficult airway and as not obese. Also, they were holding the airway open with a C-MAC and had a grade 2 view at least in all patients. The only patient in the O2 group with an early desat had a BMI of 29.9, barely meeting the max BMI 30 cutoff for inclusion. Keep this technique in mind as a way to safely deliver apneic O2.
Source
Effect of Apneic Oxygenation on Tracheal Oxygen Levels, Tracheal Pressure, and Carbon Dioxide Accumulation: A Randomized, Controlled Trial of Buccal Oxygen Administration. Anesth Analg. 2018 Oct 8. doi: 10.1213/ANE.0000000000003810. [Epub ahead of print]
