Patients with morbid obesity have an approximately 60-80 percent incidence of OSA depending on the criteria used for making diagnosis, and they are suggested to be at increased risk to develop serious perioperative complications, especially during the postoperative period. Weight loss might be considered as an appropriate treatment of OSA but in turn it has recently been reported that OSA is an independent risk factor for development of perioperative complications, importantly oxygen desaturation, in patients undergoing weight loss surgery. It seems logical to evaluate if these patients would benefit from post-operative CPAP treatment in the PACU. The results of this multidisciplinary study will have an impact on PACU treatment of patients with OSA and will further optimize patient care at MGH.