Oxygenation During Apnea Prolongs Time to Desaturation in Obese Patients

Obese patients experience more-rapid hemoglobin desaturation during apnea than nonobese patients. In a randomized controlled trial, researchers evaluated the effect of oxygen administration during simulated difficult laryngoscopy on duration of desaturation in 30 obese (body-mass index, 30–35 kg/m²) men undergoing elective surgery. After preoxygenation and intravenous induction of anesthesia with neuromuscular blockade in all patients, half the patients received supplemental nasal oxygen via nasal prongs at a rate of 5 L/minute. Difficult laryngoscopy was simulated by gentle insertion of the laryngoscope and visualization of the larynx, with delay of tracheal intubation until 6 minutes after succinylcholine administration or when arterial o…