Obstructive sleep apnea affects complication rates following knee arthroscopy but use of continuous positive airway pressure is not protective against complications

Obstructive sleep apnea (OSA) has not been studied as a risk factor for complications following knee arthroscopy. The goals of this study were to: (1) compare complication rates after knee arthroscopy between patients with and without OSA and (2) evaluate whether continuous positive airway pressure (CPAP) mitigated complication rates. A national private insurance database was queried for patients undergoing simple knee arthroscopy from 2007 to 2016. Patients with a diagnosis of OSA were then identified using ICD-9/10 codes. Patients with OSA were then subdivided into cohorts with and without a billing code for a CPAP device. Adverse events within 30 days postoperatively related to OSA were then assessed in all groups: (1) emergency room (ER) visit, (2) hospital admission, (3) pulmonary embolism (PE), (4) myocardial infarction, (5) respiratory arrest and (6) in-hospital mortality within 6 months postoperatively. Adverse event rates were compared between the control and study groups using a multivariable regression analysis. 97,036 patients underwent simple knee arthroscopy with 8656 patients having a diagnosis of OSA. Of these, 3820 (44%) had orders for CPAP machines. After controlling for confounders, patients with OSA had significantly higher risk of ER visits, PE and respiratory arrest compared to controls (p < 0.05). The majority of these significant findings persisted regardless of CPAP use. There were no significant differences in complication rates between OSA patients with and without CPAP orders. OSA appears to be independently associated with a higher risk for ER visits, PE and respiratory arrest following knee arthroscopy after controlling for demographic and comorbidity confounders. An order for CPAP was not associated with a significant reduction the risk for these complications. CPAP noncompliance may not be as important a factor when risk stratifying patients undergoing ambulatory knee arthroscopy compared to more significant medical comorbidities. III.