Preoperative RMT, aerobic exercise and respiratory physiotherapy
Upon admission, each patient was examined by professional rehabilitation therapists and specialized nurses, who evaluated the patient's pulmonary function. Patients randomized to the SG began preoperative moderate aerobic training, including an indoor treadmill and up and down stairs (two sessions per day, 45 min per session, for 5 days), to improve cardiopulmonary function. Patients also started preoperative RMT, including inspiratory muscle training (IMT) with a three-ball breathing trainers (China, SURFTIME). The training was three sessions per day, 15 min per session, for 5 days, and the training workload was up to three balls per inhalation. Meanwhile, chest physiotherapy was started, including practiced coughing and expectorating (three sessions per day, 15 min per session, for 5 days), percussion and vibration of chest wall (three sessions per day, 15 min per session, for 5 days), and forced exhalation (three sessions per day, 15 min per session, for 5 days). Subjects in the CG received only chest physiotherapy preoperatively.