To investigate the predictive value of plasma D-dimmer, B-type natriuretic peptide (BNP) and blood gas indexes in secondary pulmonary thromboembolism (PTE) during the high-risk of acute exacerbation of chronic obstructive pulmonary disease (AECOPD).

A total of 32 patients with high-risk AECOPD + secondary PTE, treated in our hospital from January 2016 to December 2017, were collected as the thrombosis group, 60 patients with high-risk of AECOPD without secondary PTE, treated at the same period, were selected as the simple high-risk COPD group, and 52 patients with low-risk COPD during the period of acute exacerbation (without secondary PTE), treated at the same period, were selected as the low-risk COPD group. The plasma D-dimmer, BNP, and blood gas indexes [the arterial partial pressure of oxygen (PaO₂) and the arterial partial pressure of carbon dioxide (PaCO₂)] were detected and analyzed in all the patients.

The mean values of plasma D-dimmer and BNP in the thrombosis group and the simple high-risk COPD group were higher than those of the low-risk COPD group. The mean value of plasma D-dimmer in the thrombosis group was higher than that of the high-risk COPD group, and statistical significant differences were found between the two groups (P<0.05). The PaCO₂ and PaO₂ in the thrombosis group were lower than those of the simple high-risk COPD group and the low-risk COPD group, and statistical significant differences were found between the two groups (P<0.05). The patients with simple high-risk COPD had higher PaCO₂ than the patients with low-risk COPD (P<0.05), however, there was no statistical significant difference in the mean PaO₂ between the two groups.

In the patients with high-risk AECOPD, the plasma D-dimmer and BNP levels are elevated, and hypoxemia and carbon dioxide retention occur. When combined with pulmonary thromboembolism, the D-dimmer and BNP levels increase more significantly, the symptoms of hypoxia are further aggravated. And on the basis of original high carbon dioxide, there is a decrease in the PaCO₂, with a mean value greater than 5 mm Hg, suggesting that the plasma D-dimmer, BNP, and blood gas analysis tests have a good predictive value in judging the high-risk AECOPD associated with pulmonary embolism. It can provide an important basis for early clinical anticoagulant therapy for the patients with acute exacerbation of high-risk COPD.