Frequency and Causes of Fluid Accumulation in the Pleural Space in the Patients Admitted to Teaching Hospitals in Hamedan City during 5 Years

Introduction: Occurrence of pleural effusion occurs in both hospitalized and outpatients. Recognizing the most important and common causes of pleural effusion in each region and in different communities can be a useful step in early and timely diagnosis of the causes and, consequently, timely treatment and thus reducing the time and burden of diagnostic and therapeutic costs imposed on patients. Methods: In this descriptive cross-sectional study, 407 patients admitted to Sina and Shahid Beheshti hospitals in Hamadan were studied by census. Data were analyzed with SPSS software (ver. 16). Results: From 407 patients with pleural effusion in this study, 262 persons (64.4%) were men and 145 (35.6%) women. There were 244 persons (60%) with exudative pleural effusion, 110 persons (27%) with transudate effusion and 53 persons (13%) with empyema. Out of 244 exudative effusion cases, in 135 cases (55.3%) were recorded pneumonia, 50 cases (20.5%) lung malignancy, 33 cases (13.5%) other malignancies, 13 cases (5.3%) tuberculosis, 7 cases (2.9%) pulmonary thromboemboli and 6 remained cases  (2.5%) were other causes. Pneumonia was the most common cause of empyema. Conclusion: According to results of this study, exudative pleural effusion was the most common type of effusions. In all types of pleural effusions, the most common site of involvement was right hemithorax. Identifying common causes of pleural effusions in each region facilitates the initial treatment of pleural effusions until reaching a definitive diagnosis.