Determination of the Cause of Pleural Effusion in ICU Patients with Thoracentesis

Background: Pleural effusion is a common and important problem in the intensive care unit (ICU). However, only few studies have focused on the etiology of pleural effusion in the ICU. The aim of this study is to elucidate the etiology of pleural effusion in ICU patients in a tertiary care hospital. Methods: Patients with pleural effusion in the medical ICU (MICU) and in the emergency ICU (EICU) were studied retrospectively from January 1, 2006 to December 31, 2009. The etiology and profile of pleural effusion were analyzed. Results: Of 1,592 patients admitted to the MICU and EICU during the study period, 78 patients (4.8%) underwent thoracentesis. The mean age was 66.8 ± 13.3 years, and 52 (66.7%) were men. Parapneumonic effusion (32/78, 41%) was the leading cause of all effusions; malignancyand heart failure-related effusions accounted for 15 (19.2%) and 14 (17.7%) cases, respectively. Fifteen patients (19.2%) had tube insertion after thoracentesis; in these patients, parapneumonic effusion or empyema was the most common reason for drainage (9/15, 60%). Pneumothorax developed after thoracentesis in 2 patients. Conclusions: Diagnostic thoracentesis was performed in 4.8% of patients admitted to the ICU; one-fifth of these cases required therapeutic drainage. Parapneumonic effusion was the most common cause of pleural effusion in the ICU in this study.