Probability of Undiagnosed Obstructive Sleep Apnea Does Not Correlate With Adverse Pulmonary Events nor Length of Stay in Hip and Knee Arthroplasty Using Intrathecal Opioid

Abstract

Background: Recent emphasis on bundled payments and outcomes tracking has increased the focus on preoperative optimization in patients undergoing elective lower extremity arthroplasty. Since patients with obstructive sleep apnea (OSA) have an increased risk of adverse perioperative pulmonary events, screening for undiagnosed OSA is sometimes included as part of preoperative risk assessment. However, there are limited data regarding quantification of OSA risk in lower extremity arthroplasty patients, and little is known about the utility of quantitative OSA screening and the risk of pulmonary complications in hip and knee arthroplasty patients who receive intrathecal morphine anesthetic.

Methods: A retrospective review of 990 patients at a tertiary care, urban academic medical center who underwent lower extremity arthroplasty with a multimodal pain regimen including intrathecal morphine anesthesia, comparing the rate of pulmonary complications and length of stay between patients previously diagnosed with OSA and those identified as low, moderate, and high risk of undiagnosed OSA established by screening with the STOP-BANG questionnaire in the preoperative setting.

Results: Using logistic regression and adjusting for age, gender, and body mass index, the results suggested the rate of complications was not different across the sleep apnea risk groups (P = .4024). In addition, linear regression suggested length of stay did not differ significantly by sleep apnea risk group (P = .2823).

Conclusion: In patients receiving intrathecal morphine as part of a multimodal pain regimen undergoing hip or knee arthroplasty, neither risk of adverse pulmonary events nor length of stay appeared to correlate with preoperative risk of undiagnosed OSA.

Keywords: STOP-BANG questionnaire; intrathecal opioid; lower extremity arthroplasty; neuraxial anesthesia; obstructive sleep apnea.