Does Diffuse Apneic Oxygenation Affect Respiratory Physiology During Prolonged Apnea?

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 post-intubation 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 r…