A Matched Cohort Study of Postoperative Outcomes in Obstructive Sleep Apnea

In this matched cohort study, the authors analyzed whether patients with obstructive sleep apnea (OSA) diagnosed from polysomnography data obtained before or after surgery from a health administrative database from Manitoba, Canada, between 1987-2008, were at increased risk for postoperative complications compared with controls. Patients with a preoperative diagnosis of obstructive sleep apnea (OSA) and prescription of continuous positive airway pressure therapy were less than half as likely to experience postoperative cardiovascular complications – specifically cardiac arrest and shock. Respiratory complications were twice as likely in OSA patients, regardless of whether the OSA diagnosis was known at the time of surgery or after surgery. The OSA severity, type of surgery, age and other comorbidities were also important risk modifiers. Although this study has the limitations inherent to using health administrative data, it is the largest study that has used polysomnography to compare perioperative outcomes between undiagnosed and diagnosed OSA.