A survey about old patients of chronic obstructive pulmonary disease to respond to bronchodilator after long-term inhalation of ipratropium bromide and salbutamol

• 长期联合吸入异丙托溴胺与沙丁胺醇的老年慢性阻塞性肺疾病患者对支气管扩张剂的反应性观察