Obstructive sleep apnea (OSA) is a prevalent sleep disorder characterized by recurrent episodes of complete or partial collapse of the upper airway that lead to intermittent hypoxemia and recurrent arousals from sleep. Although prevalence estimates of OSA from community-based studies have ranged from 5% to 28%, the prevalence of clinically significant and symptomatic OSA is significantly lower, at 2% to 9%.1-4 In contrast, the prevalence of OSA in presurgical cohorts remains less well defined. Studies that have reported a high prevalence have been subject to significant selection bias, because not all patients underwent diagnostic testing.5-7 In the largest single academic center registry study of presurgical patients undergoing anesthesia, Ramachandran et al8 reported an OSA prevalence of 7%. Importantly, chronically untreated moderate to severe OSA has been associated with significant morbidity and mortality, and treatment with CPAP has been shown to reduce cardiovascular risk in patients with severe OSA.9-11 Given the important long-term implications of untreated OSA, in 2006 the American Society of Anesthesiologists recommended screening patients prior to surgery and implementing treatment if OSA is present.12 Interestingly, these recommendations were made despite the lack of significant empirical evidence in the perioperative diagnosis and management of OSA. Since the American Society of Anesthesiologists’ publication, there has been a growing interest in the perioperative care of patients with OSA or suspected of having OSA. To date, most studies have focused on developing effective screening tools in the preoperative population13-15 or have outlined adverse postoperative outcomes in patients with OSA.5,16-21 However, despite this growing awareness, there is a paucity of well-controlled prospective studies examining the impact of OSA treatment on postoperative outcomes.