Owing to the increasing morbidity and pulmonary infection,management of pulmonary function has become an important problem for COPD patients who undergo surgery.Surgical patient with respiratory disease such as COPD has declined lung function before operation,then increased the risk of post-operative pulmonary complications.Ipratropium bromide can significantly improve pulmonary function.Therefore,we hypothesis the treatment with nebulized ipratropium bromide will benefit the perioperative patients with COPD.A randomized,double-blind,placebo-controlled,parallel-group,multi-center trial (Ipratropium bromide in Peri-Operative COPD study,IPO-COPD study)has been conducted to evaluate the efficacy and safety of nebulized ipratropium bromide in Chinese perioperative patients with COPD under general anaesthesia.A total of 192 COPD patients who satisfied the eligibility criteria were randomly assigned(1∶1) to one of the two treatment groups(ipratropium bromide 500 μg or normal saline 4 ml) for 11 days.Measurements will include the change of the forced expiratory volume in 1 second(FEV1),the forced vital capacity(FVC),blood gas analyses and main post-operative pulmonary complications.