Apneic oxygenation during prolonged laryngoscopy in obese patients: a randomized, controlled trial of nasal oxygen administration.

STUDY OBJECTIVE To evaluate the influence of nasal oxygen (O(2)) administration on the duration of arterial oxygen saturation (SpO(2)) >or=95% during simulated difficult laryngoscopy in obese patients. DESIGN Prospective, randomized, controlled trial. SETTING University hospital. PATIENTS 30 obese men undergoing general anesthesia. INTERVENTIONS After thorough preoxygenation, and using total intravenous anesthesia, simulated difficult laryngoscopy was performed, with half the patients receiving additional nasal O(2) during apnea. MEASUREMENTS Duration of SpO(2) >or=95% was measured up to a maximum of 6 minutes. Lowest SpO(2) values and time to regain 100% SpO(2) (resaturation time) also were recorded. MAIN RESULTS Nasal O(2) administration was associated with significant prolongation of SpO(2) >or=95% time (5.29 +/- 1.02 vs. 3.49 +/- 1.33 min, mean +/- SD), a significant increase in patients with SpO(2) >or=95% apnea at 6 minutes (8 vs. one pt), and significantly higher minimum SpO(2) (94.3 +/- 4.4% vs. 87.7 +/- 9.3%). Resaturation times were no different between the groups. CONCLUSIONS Nasal O(2) administration is associated with significant increases in frequency and duration of SpO(2) >or=95%, and higher minimum SpO(2) during prolonged laryngoscopy in obese patients.