Should pulmonary embolism be suspected in exacerbation of Chronic Obstructive Pulmonary Disease?

Abstract

Background: The cause of acute exacerbation of chronic obstructive pulmonary disease (COPD) is frequently difficult to determine. Pulmonary embolism may be a trigger of acute dyspnea in patients with COPD. We aimed to determine the prevalence of pulmonary embolism in patients with acute exacerbation of COPD.

Methods: We included 123 consecutive patients admitted to the emergency departments of two academic teaching hospitals for acute exacerbation of moderate to very severe COPD. Pulmonary embolism was investigated in all patients (whether or not clinically suspected) following a standardized algorithm based on D-dimer testing, lower limb venous ultrasonography and multidetector helical CT-scan.

Results: Pulmonary embolism was ruled out by a D- dimer value < 500 ƒÝg/L in 28 (23%) patients and a negative chest CT-scan in 91 (74%). CT-scan showed pulmonary embolism in 4 patients (3.3%, 95% CI 1.2- 8.0%), including 3 lobar and one sub-segmental embolisms. The prevalence of pulmonary embolism was 6.2% (n=3 )(95% CI 2.3-16.9%) in the 48 patients who had a clinical suspicion of pulmonary embolism and 1.3% (n=1) (95% CI 0.3-7.1%) when there was no suspicion. In two cases with positive CT scan, the venous ultrasonography also showed a proximal deep-vein thrombosis. No other patient was diagnosed with venous thrombosis.

Conclusions: the prevalence of unsuspected pulmonary embolism is very low in patients admitted in the emergency department for an acute exacerbation of their COPD. These results argue against a systematic work-up for pulmonary embolism in this population.