Chronic obstructive lung disease (COPD) is an independent risk factor for pulmonary thromboembolism (PTE), which often originates from deep vein thrombosis (DVT) and is a common comorbidity [1]. Autopsy data have shown that the incidence of COPD complicated with PTE is 28 %−51 %, and the incidence of pulmonary thrombosis in situ (PTS), especially multiple pulmonary arteriole in situ thrombosis, is as high as that of chronic pulmonary heart disease, 89.8 % [2]. Diagnosing acute exacerbation of COPD (AECOPD) patients with PTE/PTS as soon as possible especially for severe cases is difficult because of the lack of a specific indicator; thus, appropriate treatment may be delayed, resulting in an extension of the hospital stay, higher mortality and a worse prognosis for these AECOPD patients, indicating that timely thrombo- prophylaxis should be strengthened [3–5].
