Pleuroperitoneal Leak as an Uncommon Cause of Hydrothorax in Peritoneal Dialysis: A Case Report and Literature Review
A 56-year-old male presented with a 2-day history of acute-onset shortness of breath. The dyspnea worsened when lying on the left side, and relieved when leaning toward the opposite side. He had no sweating nor fever. The past medical history includes hypertension, hyperlipidemia and End-Stage Renal Disease (ESRD) managed with continuous ambulatory peritoneal dialysis (PD) since March 2020. His last peritoneal dialysis was two days ago; at the initial period of PD, he did not report any discomfort. He reported indwelling 1.5L volume of dialysate, which no drainage was observed after completion of the therapy. Subsequently, he developed acute onset of difficult breathing associated with chest tightness. He denied any diaphragmatic trauma or surgery. On examination, his vital signs were a temperature of 36.7°C, blood pressure of 141/53mm Hg, heart rate of 87 beats/min, respiratory rate of 19 breaths/min, and O2 saturation of 86% on ambient air that improved to 96-97% on Bilevel Positive Airway Pressure (BiPAP). On examination, the patient was in respiratory distress and absent breath sounds on the right lung field. His general and cardiovascular examinations were normal. Full blood count, urea and electrolytes, coagulation profile, and liver function tests were normal. His brain-natriuretic peptide (NT-proBNP) level was 88 pg/mL (normal <100pg/mL). High sensitivity cardiac troponin T (hscTnT) on admission and at 6hours were 5ng/L and 5ng/L, respectively (normal <14ng/L). Electrocardiography revealed a normal sinus rhythm without ST-T segment abnormality. Transthoracic echocardiogram (TTE) demonstrated a left ventricular ejection fraction of 55%. Admission serum and nasopharyngeal swab specimen samples were sent for analysis and were negative. However, the patient reported a 2-week prior history of positive Coronavirus Disease 2019 (COVID-19) nasopharyngeal swab. The patient was admitted for evaluation and treatment of hydrothorax.
Chest X-ray radiography revealed a massive right-sided pleural effusion (figure 1). Computed Tomography (CT) of the chest scan confirmed a large right pleural effusion. A therapeutic thoracentesis was performed in order to relieve the dyspnea and obtain pleural fluid specimens; from which, 2000 mL of white to faint yellow-colored fluid was drained. The pleural fluid tests included: pleural fluid routine, bacterial culture, tumor markers, and others. The pleural fluid sample was found to have a Lactate Dehydrogenase (LDH) level = 34U/L, protein < 2.4g/ dL, and glucose = 105mg/dL compatible with transudate. In contrast, the results of blood examination were as follows: serum LDH = 275U/L, serum protein = 5.7g/ dL and serum glucose = 85mg/dL. The bacterial cultures showed no evidence of infection, and at the same time, there was no evidence of tumor or tuberculosis. Repeat chest x-ray showed resolution of the hydrothorax (figure 2). At this point, he was suspected to have pleuroperitoneal leakage from the peritoneal dialysis and the interventional radiology team was notified to perform diagnostic CT imaging and potential temporary conversion to hemodialysis. CT peritoneography using 100mL/kg nonionic iodixanol contrast medium (100 ml of Visipaque 320mg/mL) was mixed with 2L of dialysate and administered into the peritoneal cavity. A one-hour follow-up non-contrast CT scan from the thorax to the pelvis was again performed. Close inspection of a right pleural effusion demonstrated an increase in size and in fluid density when compared to pre-dialysate administration (figure 3). The attenuation coefficients in Hounsfield Units (HU) of the peritoneal dialysate in the pelvis were evaluated at 138 HU, and the CT value of the right pleural effusion at the same site increased from 4 to 66 HU (figure 4). These findings suggest migration of the contrast medium from the peritoneal to thoracic cavity confirming the diagnosis of pleuroperitoneal communication. The patient was educated and presented the choices of management, which he elected termination of PD and permanently transferred to hemodialysis through a tunneled central venous catheter. The patient was asymptomatic on respiratory examinations during the remainder of the admission course and subsequently discharged. In follow up, he has shown no recurrence of the hydrothorax. There were no thoracic masses or acute infectious processes.
Pleuroperitoneal leak should be considered in the differential diagnosis of large pleural effusion in patients with acute-onset dyspnea with a history of continuous ambulatory peritoneal dialysis. Once a pleuroperitoneal communication is suspected, accompanying radiologic imaging and the pleural fluid assay is useful for the diagnosis and treatment planning, as the best management approach varies on each clinician and practice.