Continuous Positive Airway Pressure via the Boussignac System Immediately after Extubation Improves Lung Function in Morbidly Obese Patients with Obstructive Sleep Apnea Undergoing Laparoscopic Bariatric Surgery

Background: Morbidly obese patients are at elevated risk of perioperative pulmonary complications, including airway obstruction and atelectasis. Continuous positive airway pressure may improve postoperative lung mechanics and reduce postoperative complications in patients undergoing abdominal surgery. Methods: Forty morbidly obese patients with known obstructive sleep apnea undergoing laproscopic bariatric surgery with standardized anesthesia care were randomly assigned to receive continuous positive airway pressure via the Boussignac system immediately after extubation (Boussignac group) or supplemental oxygen (standard care group). All subjects had continuous positive airway pressure initiated 30 min after extubation in the postanesthesia care unit via identical noninvasive ventilators. The primary outcome was the relative reduction in forced vital capacity from baseline to 24 h after extubation. Results: Forty patients were enrolled into the study, 20 into each group. There were no significant differences in baseline characteristics between the groups. The intervention predicted less reduction in all measured lung functions: forced expiratory volume in 1 s (coefficient 0.37, SE 0.13, P = 0.003, CI 0.13-0.62), forced vital capacity (coefficient 0.39, SE 0.14, P = 0.006, CI 0.11-0.66), and peak expiratory flow rate (coefficient 0.82, SE 0.31, P = 0.008, CI 0.21-0.1.4). Conclusions: Administration of continuous positive airway pressure immediately after extubation maintains spirometric lung function at 24 h after laparoscopic bariatric surgery better than continuous positive airway pressure started in the postanesthesia care unit.