The purpose of this study is to assess the efficacy of the Boussignac positive airway pressure system (a mask) applied immediately following post-operative extubation in improving lung function in patients with obstructive sleep apnea (OSA). Assessments will be done before surgery and then at 1, 2 and 24 hours following extubation and will be compared to standard care for perioperative airway support. The study aims to give a broader and more inclusive picture (than the current literature) in terms of whether the Boussignac CPAP system should be considered for utilization by anesthesiologists caring for surgical patients with OSA.