Pulmonary Embolism And Chronic Obstructive Pulmonary Disease

The chronic obstructive pulmonary disease (COPD) is a major health burden worldwide.It is the fourth-leading cause of mortality, accounting for 3 million deaths annually.By 2020,COPD will be the third-leading cause of death, trailing only ischemic heart disease and stroke. Most COPD-related deaths occur during periods of exacerbation.Studies estimate that 50% to 70% of all acute exacerbations of COPD (AECOPD) are precipitated by an infectious process, while 10% are due to environmental pollution.Up to 30% of exacerbations are caused by an unknown etiology.Since venous thromboembolic (VTE) events can lead to cough and dyspnea, Pulmonary embolism (PE) may be another common cause of AECOPD. It is suspected that 25% patients with atypical COPD exacerbation may have PE as an underlying or concomitant cause of acute dyspnea.Patients with COPD have approximately twice the risk of PE and other VTE than those without COPD. The presentation of PE is similarly subtle with nonspecific clinical features such as acute dyspnea, tachycardia, and pleuritic chest pain.COPD patients presenting with acute dyspnea can be a diagnostic challenge. Typical features of fever, productive cough, and wheezing on presentation support COPD exacerbation, while absence of such findings may warrant further evaluation for underlying etiologies.Many cardiopulmonary diseases,including PE, are worsened or masked by the presence of COPD. There are no proven clinical criteria to help delineate PE from COPD. This is attributable to the overlap and nonspecificity of clinical features common to both diseases.Owing to multiple perfusion and ventilation abnormalities frequently observed in COPD lungs, noninvasive diagnosis of PE using imaging modalities was a significant challenge until quite recently.With the advent of contrast enhanced CT, it is now possible to reliably diagnose PE in COPD subjects with minimal discomfort or risk to the patients.However, dissimilar to infectious etiologies, which are effectively treated by antimicrobialsand systemic corticosteroids, thromboembolic diseases require anticoagulant therapy and significant delays in treatment are associated with poor outcomes.The mortality of untreated PE may be as high as 25%,so it is crucial to incorporate PE into the differential diagnosis of an AECOPD. While COPD remains a clinical diagnosis, PE requires objective confirmation of clot by an imaging study to warrant appropriate anticoagulation therapy. This review discusses the clinical characteristic of PE in COPD patients, and presents an overview of the diagnosis and treatment.