Exercise oxygen desaturation is a predictor of cardiopulmonary complications after lung resection

BACKGROUND: To investigate whether oxygen desaturation during low technology tests was associated with complications after lung resection. METHODS: A retrospective cohort study was conducted on 1097 candidates for pulmonary resection; seven metabolic equivalents in the Master’s double two-step test were loaded. The predicted postoperative (PPO) forced expiratory volume in 1 s and PPO diffusing capacity of the lung for carbon monoxide were estimated. The patients were divided into three groups: those with both values ≥60% (≥60% group (n=298)), either value <30% (<30% group (n=112)) and others (30%–60% group (n=687)). The relationships between postoperative cardiopulmonary complications and exercise stress test based on availability, symptoms and percutaneous oxygen saturation values were investigated in each group. RESULTS: Τhe cardiopulmonary morbidity rates in the ≥60%, 30%–60%, and <30% groups were 7.7%, 14.6%, and 47.3%, respectively. Multivariate analyses revealed that predictors of complications were age (OR 0.96; p<0.001), male sex (OR 1.74; p=0.016) and exercise oxygen desaturation (EOD) >4% (OR 2.39; p=0.001) in the 30%–60% group, and male sex (OR 3.76; p=0.042) and EOD >4% (OR 2.28; p=0.030) in the <30% group. The two-flight test (TFT) was performed in 181 patients (22.8%); desaturation >4% in the TFT was also a predictor of complications. CONCLUSIONS: A low technology test is also valuable for high-risk patients. EOD >4% is a predictor of postoperative complications. CLINICAL REGISTRATION: This study is a non-interventional observational study and has not been registered in a public database. The study followed the Strengthening the Reporting of Observational Studies in Epidemiology reporting guidelines. This study was approved by the Ethics Committee of the Juntendo University School of Medicine (no. 2016085).