Clinico-etiological features of iatrogenic urinothorax: a systematic review

SESSION TITLE: Pleural Effusions SESSION TYPE: Original Investigations PRESENTED ON: 10/10/2023 10:30 am - 11:30 am PURPOSE: Urinothorax (UT) is a rare cause of pleural effusion caused by either trauma or obstruction of the urinary tract. The objective of this review is to understand the clinic-etiological features of iatrogenic cases of UT. METHODS: A comprehensive search was conducted in publicly available databases after registering the study in PROSPERO. Out of ninety-nine studies (117 patients) that reported individual cases or cases series of UT, sixty-five (71 patients) were due to iatrogenic causes and thus, included in the final review (from 1974 to 2021) . A descriptive analysis was performed for demographics, symptoms, biochemical characteristics, and treatment modalities. RESULTS: Out of 514 studies screened, ninety-nine (117 patients) met inclusion criteria. 65 out of 99 studies that included 71 patients with UT secondary to iatrogenic etiology. Mean age in years (median, range) was 44.3 (50, 3-84) (data missing for 4 patients). 38 (53.5%) were females (data was missing for 4 patients). Most common presenting symptom was dyspnea followed by constitutional symptoms and chest pain. The etiologies for iatrogenic UT were noted to be nephrolithotomy (24, 33.8%) followed by nephrostomy (19, 26.8%) and surgeries of genital tract (7, 9.9%).Only one case has been reported due to stent migration. The pleural effusion was noted to be right-sided in 41 (56.4%) patients, left-sided in 23 (32.4%), and bilateral in 4 (5.6 %) (rest not available). 40 (56.3%) of the effusions were ipsilateral, and only six (8.5%) were contralateral to the side of the underlying etiology (data unavailable for 25 patients). 70 (98.6%) underwent thoracentesis for pleural fluid analysis. For one patient, the studies were sent from the fluid collected from intercostal drain insertion. The fluid was transudative in 30 (42.3%) and exudative in 19 (26.8%) patients based on Light's criteria. Information was unavailable for rest of the patients (22, 30.9%). Amongst 18 patients with exudative effusion, four patients had protein accordant and six patients had protein discordant results. Pleural fluid studies revealed pH ≤ 7.3 in 18 (25.4%) patients and ≥ 7.5 in 10 (14.1%) patients (data unavailable in 40 patients). As expected, the pleural to serum creatinine ratio was more than one in most patients (53, 76.4%). Two patients had elevated urea levels and only in two patients was the ratio less than one. For 14 patients, the data was not available as the diagnosis was made clinically. The pleural fluid lactate dehydrogenase (LDH) levels were available for 26 patients (Mean, range: 43, 39-3475). The treatment modalities were varied, ranging from thoracentesis (70, 98.6%), intercostal drain insertion (31,43.7%) to some patients ultimately requiring nephrectomy (4, 5.6%). Spontaneous resolution was reported in 6 patients and four patients ultimately died (details not available). CONCLUSIONS: UT is a potential treatable cause of pleural effusion and it's not uncommon for individuals to have UT due to iatrogenic causes. CLINICAL IMPLICATIONS: More than half (60.7%) of 117 patients presenting with UT had underlying iatrogenic etiology. It is imperative to keep UT as differntial for patients presenting with respiratory/urological symptoms post the above procedures. DISCLOSURES: No disclosure submitted for Jaideep Singh Bhalla No relevant relationships by Dheera Grover No relevant relationships by Prashant Grover No relevant relationships by Simrina Sabharwal No relevant relationships by Ushasi Saraswati