A stepwise approach to the etiologic diagnosis of pleural effusion in respiratory intensive care unit and short-term evaluation of treatment

BACKGROUND: Pleural effusions in respiratory intensive care unit (RICU) are associated with diseases of varied etiologies and often carry a grave prognosis. This prospective study was conducted to establish an etiologic diagnosis in a series of such patients before starting treatment. MATERIALS AND METHODS: Fifty consecutive patients, diagnosed with pleural effusion on admission or during their stay in RICU, were further investigated by a two-step approach. (1) Etiologic diagnosis was established by sequential clinical history and findings on physical examination, laboratory tests, chest radiograph, CECT/HRCT/PET-CT and pleural fluid analysis. (2) Patients who remained undiagnosed were subjected to fiber-optic bronchoscopy, video-assisted thoracoscopic pleural biopsy, and histopathology. RESULTS: Etiologic diagnosis of pleural effusion was established in 44 (88%) Metastases (24%); para-pneumonia (22%); congestive cardiac failure (18%); tuberculosis (14%); hemothorax (4%); trapped lung, renal failure, and liver cirrhosis (2% each). Six patients (12%) remained undiagnosed, as the final diagnostic thoracoscopic biopsy could not be performed in five and tissue histopathology findings were inconclusive in one. Out of the 50 patients, 10 died in the hospital; 2 left against medical advice; and 2 were referred to oncology center for further treatment. The remaining 36 patients were clinically stabilized and discharged. During a 3-month follow-up, eight of them were re-hospitalized, of which four died. CONCLUSIONS: Pleural effusion in RICU carries a high risk of mortality. Etiologic diagnosis can be established in most cases.