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)) >= 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) >= 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) >= 95% time (5.29 +/- 1.02 vs. 3.49 +/- 1.33 min, mean SD), a significant increase in patients with SpO(2) >= 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) >= 95%, and higher minimum SpO(2) during prolonged laryngoscopy in obese patients. (C) 2010 Elsevier Inc. All rights reserved.