Pleural Effusions in the Medical ICU

To determine the prevalence and causes of pleural effusions in patients admitted to a medical ICU (MICU). Prospective. MICU in a tertiary care hospital. One hundred consecutive patients admitted to the MICU at the Medical University of South Carolina whose length of stay exceeded 24 h had chest radiographs reviewed daily and chest sonograms performed within 10 h of their latest chest radiograph. The prevalence of pleural effusions in 100 consecutive MICU patients was 62%, with 41% of effusions detected at admission. Fifty-seven of 62 (92%) pleural effusions were small. Causes of pleural effusions were as follows: heart failure, 22 of 62 (35%); atelectasis, 14 of 62 (23%); uncomplicated parapneumonic effusions, seven of 62 (11%); hepatic hydrothorax, five of 62 (8%); hypoalbuminemia, five of 62 (8%); malignancy, two of 62 (3%); and unknown, three of 62 (5%). Pancreatitis, extravascular catheter migration, uremic pleurisy, and empyema caused an effusion in one instance each. Heart failure was the most frequent cause of bilateral effusions (13/34 [38%]). When compared with patients who never had effusions during their MICU stay, patients with pleural effusions were older (54±2 years, mean±SEM, vs 47±2 years [p=0.04]), had lower serum albumin concentration (2.4±0.1 vs 3.0±0.01 g/dL [p=0.002]), higher acute physiology and chronic health evaluation II scores during the initial 24 h of MICU stay (17.2±1.1 vs 12±1.2 [p=0.010]), longer MICU stays (9.8±1.0 vs 4.6±0.7 days [p=0.0002]), and longer mechanical ventilation (7.0±1.3 vs 1.9±0.7 days [p=0.004]). No patient died as a direct result of his or her pleural effusion. Chest radiograph readings had good correlation with chest sonograms (p