Authors: West JR et al., Am J Emerg Med 2017 Apr 2;
In patients undergoing endotracheal intubation who had apnea for >60 seconds, DAO correlated with increased pH and decreased PaCO2.
Diffuse apneic oxygenation (DAO) uses high-flow nasal cannula oxygen during laryngoscopy for endotracheal intubation. This approach is believed to flush CO2 from the lungs and to improve respiratory physiology, but some are skeptical about biological plausibility (NEJM JW Emerg Med Mar 2016 and Acad Emerg Med 2016; 23:703; NEJM JW Emerg Med Feb 2015 and Ann Emerg Med 2015; 65:371).
Investigators at a U.S. level 1 trauma center studied a convenience sample of 100 patients who were intubated in the emergency department and had pre- and postintubation arterial blood gas measurements as part of routine care. They compared pH and PaCO2 values after intubation in patients with prolonged apnea (>60 seconds) and those without, and in patients who received DAO and those who did not (at provider discretion). DAO was not associated with any benefit in the group without prolonged apnea. However, in the group with prolonged apnea, pH was 0.15 points lower and PaCO2 was 12.5 mm Hg higher when DAO was used.