Preoperative risk stratification for thoracic surgery using the American College of Surgeons National Surgical Quality Improvement Program data set: functional status predicts morbidity and mortality

Abstract

BackgroundPreoperative risk stratification for noncardiac thoracic surgery focuses on predicting postoperative lung capacity and cardiac risk. We hypothesized that preoperative functional status may be a predictor of morbidity and mortality after thoracic surgery. MethodsThe National Surgical Quality Improvement Program Participant Use Files from 2005 to 2009 were accessed, and current procedural terminology codes for procedures involving the lung and pleura were used to identify thoracic surgery patients. Patients were grouped by independent or dependent preoperative functional status. Risks of infectious and noninfectious complications were evaluated. Chi-square, Fisher exact, and multivariate analyses with stepwise logistic regression were used. This study was approved by the Institutional Review Board. ResultsOf 6,373 patients, 812 had a preoperative dependent functional status. Dependent patients had significantly higher rates of infection, other adverse events, and mortality. They were 9.3 times more likely (odds ratio [OR] 9.3) to have prolonged ventilation (P < 0.001) and 3.1 times more likely to be reintubated (P < 0.001). Postoperative pneumonia occurred in 10% (OR 2.7, P < 0.001). Postoperative mortality was 7.7 times higher (P < 0.001). Preoperative functional status, wound classification 3, and emergency procedures were independent predictors of both morbidity and mortality. Performing a thoracotomy was an independent risk factor for postoperative morbidity but not mortality (P < 0.001, OR 2 versus P = 0.415, OR 1.1). ConclusionsThoracic surgery patients, classified as functionally dependent preoperatively are at high risk for major morbidity and mortality. Although a limited observational study, results show that functional status is an essential component of preoperative assessment for thoracic surgery patients.