Lung Ultrasound Guided Prevention of Postoperative Pulmonary Complications in Moderate to High Risk Patients

patients recruited are randomized into the two groups: LUS group and Control group. Patients in LUS group received ultrasound examination and guided the treatment according to the ultrasound results, while the control group did not receive ultrasound examination, just the same as the routine clinical practice. This study aims to explore whether ultrasound-guided clinical treatment can reduce the incidence of postoperative pulmonary complications in moderate to highrisk patients. Before operation, informed consent was signed according to the inclusion criteria, and the incidence of pulmonary complications within 5 days after operation (or before discharge) was recorded after operation.