Background: The cause of acute exacerbation of chronic obstructie pulmonary disease (COPD) is often difficult to determine. Pulmonary embolism may be a trigger of acute dyspnoea in patients with COPD.

• 背景：慢性阻塞性肺病（copd）急性加重的原因往往不易确定，肺血栓栓塞可能是慢性阻塞性肺病患者急性呼吸困难的触发因素。