无创呼吸机治疗COPD合并Ⅱ型呼吸功能衰竭的临床疗效观察
무창호흡궤치료COPD합병Ⅱ형호흡공능쇠갈적림상료효관찰
Non-invasive ventilation in COPD patients with type Ⅱ respiratory failure and clinical efficacy