[Risk factors for pulmonary embolism in acute exacerbation of chronic obstructive pulmonary disease]

To study the risk factors for acute pulmonary embolism (PE) in patients with acute exacerbation of chronic obstructive pulmonary disease (AECOPD).

From November of 2009 to May of 2014, 522 admitted patients [aged 42-93 years, mean(72±9)] with AECOPD received CT pulmonary angiography(CTPA) in the First Affiliated Hospital of Guangzhou Medical University. The patients were classified as PE positive (positive result on CTPA) or PE negative (negative results on CTPA), and related risk factors for PE were analyzed.

The frequency of PE was 10.3% in this series of 522 patients with AECOPD. Single factor analysis showed that the following factors were significantly different (χ(2)=4.32-57.06, mean P<0.05)between PE positive and PE negative groups: age≥70 years, immobilization≥3 days, deep vein thrombosis(DVT) and a history of venous thromboembolism(VTE), cor pulmonale caused by COPD, pneumonia, stroke, artery embolization, atrial fibrillation, lower extremity edema, the levels of N-terminal pro-brain natriuretic peptide(NT-proBNP) and D-dimmer. Multiple regression analysis showed that immobilization ≥3 days(OR=25.36, 95%CI: 7.42-86.69, P<0.001), lower extremity edema(OR=7.34, 95%CI: 3.43-15.71, P<0.001) and D-dimmer≥2 000 μg/L(OR=10.10, 95%CI: 2.25-45.42, P=0.003) were the risk factors. The ratio for purulent sputum was 48.1%(26/54) in the PE positive group, and 42.6% (23/54) of the patients showed concurrent purulent sputum and increase of blood markers of infection. The frequency of purulent sputum between PE positive and PE negative groups was not different.

Patients with AECOPD admitted to hospital should be considered for the presence of PE if they had the risk factors of immobilization≥3 days, lower extremity edema and D-dimmer ≥2 000 μg/L.