Preoperative six-minute walk distance is associated with pneumonia after lung resection

OBJECTIVES: Little is known about the relationship between preoperative physical fitness and postoperative pneumonia after lung resection. We examined the association between preoperative 6-min walk distance (6MWD) and postoperative pneumonia. METHODS: A retrospective study was conducted on patients with malignant lung tumours who were scheduled to undergo lung resection at Nagoya University Hospital from January 2014 to December 2015. Preoperative pulmonary function tests and the 6-min walk test were assessed. A logistic regression model and receiver operating characteristic curves were used to analyse clinical variables and compare the performance on 6MWD, forced expiratory volume in 1 s and diffusion capacity of the lung for carbon monoxide. RESULTS: The data from a total of 321 patients including 283 with primary lung cancer and 38 with metastatic lung tumours were analysed. Pneumonia developed in 13 patients and caused longer hospital stays after surgery. The preoperative 6MWD of patients with pneumonia was significantly lower than that without pneumonia (425 vs 500 m, P = 0.002). In receiver operating characteristic analysis, 6MWD ≤ 450 m was a threshold for predicting postoperative pneumonia with 69.2% sensitivity and 71.1% specificity. A 6MWD ≤ 450 m, forced expiratory volume in 1 s <80% of the predicted value, diffusion capacity of the lung for carbon monoxide <80% of the predicted value, serum albumin <3.5 g/dl and blood loss during surgery ≥200 g were significantly associated with postoperative pneumonia in a logistic model. CONCLUSIONS: Preoperative 6MWD was significantly associated with postoperative pneumonia in patients who underwent lung resection for malignancies.