The Effect of Obstructive Sleep Apnea on Postoperative Respiratory Complications

Abstract

Purpose: Postoperative respiratory complications (PRCs) are associated with significant morbidity, mortality, and costs. Obstructive sleep apnea (OSA), which is often undiagnosed in the surgical population, may be a contributing factor. Methods: We conducted an observational study of adult surgical patients at Partners HealthCare hospitals (2007-2014) using electronic patient and perioperative data. OSA was defined as the occurrence of an OSA diagnostic code preceded by a polysomnography procedure code. A priori defined variables were analyzed by multivariable logistic regression analysis to develop our score. Score validity was assessed by investigating the score’s ability to predict noninvasive ventilation. Following the development of our Score for Preoperative Prediction of Obstructive Sleep Apnea (SPOSA), we assessed the effect of high OSA risk on our primary outcome, PRCs within seven postoperative days. In order to improve the clinical utility of the score, a dichotomized OSA risk scale was developed using the SPOSA cut point of 7. Propensity score matched cohorts were used to understand patient and health care outcomes among patients identified as high risk for OSA. Results: Predictors for OSA included BMI >25 kg/m2 and comorbidities, including hypertension, diabetes, and dyslipidemia. The score yielded an area under the curve of 0.81. Inclusion of early postoperative desaturation did not improve the score. Noninvasive ventilation was significantly associated with high OSA risk (odds ratio 1.45, 95% confidence interval 1.20-1.76, p<0.001), confirming the validity of the SPOSA. Using a dichotomized endpoint, 29,087 patients were identified as high risk for OSA and 7.7% of these patients experienced PRCs. OSA risk was significantly associated with PRCs (OR 1.38, 95% CI 1.1.26-1.51, p<0.001). High OSA risk was also significantly associated with increased postoperative length of stay, increased total costs of care, and higher rates of admission to the intensive care unit, adverse discharge, and readmission within 30 days of initial discharge. Conclusions: The SPOSA assesses OSA risk and predicts the occurrence of respiratory complications. High OSA risk is associated with adverse clinical and care outcomes. Utilization of the SPOSA will allow providers to risk stratify patients prior to admission and may help reduce perioperative consequences of OSA.