Introduction: Patients suffering from chronic obstructive pulmonary disease (COPD) are often admitted to hospital with an exacerbation of their disease that manifests itself with an increase in cough and/or sputum, increased dyspnoea and sometimes chest pain. These episodes are most often attributed to an acute exacerbation of bronchial infection but the real cause is often unknown. COPD is considered a risk factor for pulmonary embolism (PE) and PE is part of the differential diagnosis of an acute exacerbation of COPD. However, the symptoms of these two conditions overlap to a considerable extent and the investigation of PE is often ignored in these patients. Therefore the true prevalence of PE in this situation is unknown. Nevertheless several small series suggest that up to 30% of patients seen as emergencies with exacerbations of COPD may have a deep vein thrombosis or PE. The aims of this study are therefore: 1. To evaluate the prevalence of PE in patients admitted as emergencies with exacerbations of COPD; and 2. To attempt to develop a prediction guide for PE in this population in order to identify the patients in whom PE should be investigated.
Materials and methods: 600 consecutive patients admitted as emergencies with exacerbations of COPD will be included in a cross sectional study in three university hospitals (Geneva and Lausanne in Switzerland, and Amiens in France). Patients fulfilling the inclusion criteria will be investigated by a diagnostic algorithm appropriate for the study of PE, including D-dimer levels and, in those with abnormal results, ultrasonic scan of the deep veins of the legs and spiral CT scan. The patient characteristics on admission will be incorporated in a multivariate regression analysis in an attempt to identify the predictive factors for PE in these patients. The expected duration of the study is 24 months.
Expected results: This study should determine the prevalence of PE in patients admitted as emergencies with exacerbations of COPD and therefore help decide when, and in which patients, a systematic search for PE should be undertaken.