Obstructive sleep apnea has been associated with postoperative complications. We hypothesized that postoperative autotitrating positive airway pressure (APAP) applied to patients at high risk for obstructive sleep apnea would shorten hospital stay and reduce postoperative complications.
Included were patients aged 18 to 100 years scheduled for elective total knee or hip arthroplasty who were able to give informed consent. Patients without contraindication to positive airway pressure therapy were divided into a high- or low-risk group on the basis of the Flemons sleep apnea clinical score. Low-risk patients received standard care. High-risk patients were randomized to receive standard care or standard care plus postoperative APAP. All patients were administered a predismissal cardiorespiratory sleep study. The primary end point was length of stay, and secondary end points were a range of postoperative complications.
One hundred thirty-eight patients were enrolled in the study (52 in the low-risk group, 86 in the high-risk group). Within the high-risk group, 43 were randomized to standard care and 43 to standard care plus postoperative APAP. There were no significant differences in the length of stay (P = .65) or any of the secondary end points between the randomized groups. On subgroup analysis of patients with an apnea-hypopnea index of ≥ 15, patients randomized to APAP had a longer postoperative stay (median, 5 vs 4 days; P = .02).
The role for empirical postoperative APAP requires further study, but the findings did not show benefit for APAP applied postoperatively to positive airway pressure-naive patients at high risk for sleep apnea.