A study showed that a metric of obstructive sleep apnea (OSA), including oxygen desaturation and frequency of obstruction, predicts complications after major non-cardiothoracic surgery.[1] Patients with OSA have a 50% higher risk of cardiac complications in the first 30 days after surgery compared to patients without OSA.[1] In patients with severe OSA, the risk of cardiac death is 14-fold, the risk of heart damage is 80% higher, and the risk of heart failure is nearly 7-fold.[1] The study followed 1218 patients with newly diagnosed sleep apnea before surgery.[1] Up to 80% of men and 90% of women with OSA are unaware of the condition.[1] Preoperative CPAP treatment reduces the risk of cardiovascular complications to less than half in diagnosed patients.[5] Undetected OSA is present in 30% of surgical patients.[1] Patients with OSA symptoms should be treated before major surgery.[1]