Postoperative hypoxemia: common, undetected, and unsuspected after bariatric surgery.

Background: Patients undergoing gastric bypass are at greater than ordinary risk for postoperative respiratory insufficiency, presumably related to obstructive sleep apnea (OSA) and patient-controlled analgesia (PCA). This study was proposed to quantify the magnitude of the problem.

Methods: Fifteen patients undergoing gastric bypass had oxygen saturation (SpO(2)) recorded continuously, but not displayed, for 24h postoperatively; eight also had arterial blood analysis every 4h.