A47-30 When Cirrhosis Crosses the Diaphragm: A Pulmonary Manifestation Misattributed to Heart Failure

Introduction Shortness of breath is a common and nonspecific presenting complaint, frequently attributed to cardiopulmonary causes such as heart failure, COPD, or pneumonia. Less common etiologies must be considered, particularly in patients with significant comorbidities. Hepatic hydrothorax is an uncommon complication of advanced liver disease, defined as a transudative pleural effusion, typically right-sided. Due to its rarity, diagnosis is often delayed. We present a patient initially thought to have acute decompensated heart failure whose true etiology was hepatic hydrothorax as the sole manifestation of cirrhosis. Case Presentation A 60-year-old woman was admitted with presumed heart failure exacerbation and pleural effusion after four days of progressive dyspnea, dry cough, and leg edema. Chest radiograph revealed bilateral vascular congestion with right basilar opacities, and CT angiography showed a moderate-to-large right pleural effusion. She received intravenous diuretics, bronchodilators, budesonide, ceftriaxone, and azithromycin. Despite treatment, her oxygen requirements increased. Thoracentesis on hospital day seven yielded 1100 mL of clear, straw-colored fluid consistent with transudate. Infectious studies including pleural, sputum, and blood cultures were negative. Persistent hypoxia prompted repeat thoracentesis on day nine, removing 800 mL of similar fluid. Echocardiogram revealed a preserved left ventricular ejection fraction, and right and left heart catheterizations were unremarkable, making cardiac etiology less likely. Further review revealed a history of stage IV hepatic fibrosis, prompting the diagnosis of hepatic hydrothorax. She was transferred to a tertiary center for definitive management with transjugular intrahepatic portosystemic shunt (TIPS). Discussion Hepatic hydrothorax occurs when ascitic fluid traverses microscopic diaphragmatic defects into the pleural space due to negative intrathoracic pressure gradients. Unlike heart failure or parapneumonic effusions, which are typically bilateral or exudative, hepatic hydrothorax often presents as a unilateral right-sided transudate. The condition may develop even in the absence of clinically apparent ascites, making recognition challenging. Diagnostic clues include unilateral, recurrent transudative effusions with normal cardiac and renal function. Management begins with sodium restriction and diuretics. Repeated thoracentesis offers temporary relief but carries risk of infection and protein loss. Refractory cases benefit from transjugular intrahepatic portosystemic shunt (TIPS), which lowers portal pressure and reduces recurrence. Hepatic hydrothorax should be included in the differential diagnosis for unexplained unilateral transudative pleural effusion, even in the absence of other cirrhosis stigmata. Early identification prevents unnecessary interventions such as chest tube placement, which increases morbidity and mortality in this population. Early recognition and multidisciplinary management, including gastroenterology consultation and TIPS evaluation, are crucial to improving outcomes.