Urinothorax: a systematic review.

Abstract

The characteristics of patients with urinothorax (UT) are poorly defined. A systematic review was performed searching for studies reporting clinical findings, pleural fluid (PF) characteristics, and the most effective treatment of UT. Case descriptions and retrospective studies were included. The review included 78 studies with a total of 88 patients. Median age was 45 years, male/female ratio was 1.6:1 and in 76% of cases the etiology was trauma. Pleural effusion (PE) was predominantly unilateral (87%) and occupied over 2/3 of the hemithorax in most cases (64.4%). PF was straw-colored (72.7%) or hematic (27.3%) with urine-like odor in all cases. PF was transudate in 56.2% of cases (18/32) and among 14 exudates (43.8%), 3 were concordant exudates, 1 protein-discordant and 10 LDH-discordant, with lymphocyte (44.4%) and neutrophil (38.5%) predominance. The PF/serum (PF/S) creatinine ratio was >1 in all cases except one (97.9%). The diagnosis was established on the basis of PF/S creatinine ratio >1 (56.6%), urinary tract contrast extravasation (12%), abnormal computed tomography (8.4%), laparotomy findings (6%), and association of obstructive uropathy with PE (6%). The outcome was favorable (74/77; 96.1%) when treatment was direct towards the uropathy (alone or associated with thoracentesis/thoracic drainage). Outcome was unfavorable in the 15 patients who were only treated with thoracentesis/thoracic drainage. UT is usually traumatic, unilateral, and PF does not have a specific pattern or cellularity predominance, with a PF/S creatinine ratio almost always >1. Treatment should include the uropathy, with or without PF evacuation.