Hepatic Hydrothorax in Decompensated Hepatitis B Infection

Pathophysiology and Clinical Characteristics

Hepatic hydrothorax is defined as the accumulation of transudate in the pleural space of patients with decompensated cirrhosis in the absence of cardiac, pulmonary, or pleural disease, and is associated with a poor prognosis, with median survival ranging from 8-12 months 1.
The primary mechanism involves the movement of ascitic fluid from the peritoneal cavity into the pleural space through small diaphragmatic defects, which are more often located on the right side 1, 2.
The pleural fluid in hepatic hydrothorax is a transudate with low protein content and a serum-to-pleural fluid albumin gradient greater than 1.1 g/dl, according to the European Association for the Study of the Liver 2.

Cardiopulmonary and primary pleural diseases must be ruled out before diagnosing hepatic hydrothorax, and diagnostic thoracentesis is essential, especially when infection of the pleural effusion is suspected, as recommended by the American Thoracic Society 2, 4.
The first-line treatment relies on the management of ascites with diuretics and salt restriction, and therapeutic thoracentesis is indicated in patients with dyspnea, but provides only transient relief, according to the American Association for the Study of Liver Diseases 2, 4.
Transjugular intrahepatic portosystemic shunt (TIPS) is recommended for recurrent symptomatic hepatic hydrothorax in selected patients, and liver transplantation represents the best option for patients with refractory hepatic hydrothorax when indicated and possible, as recommended by the European Association for the Study of the Liver 2, 4.

For patients with decompensated hepatitis B cirrhosis specifically, antiviral therapy with nucleos(t)ide analogues (NAs) should be initiated immediately if HBV DNA is detectable, regardless of the level of replication, and can significantly modify the natural history of decompensated cirrhosis, improving liver function and increasing survival, according to the American Association for the Study of Liver Diseases 5, 6.
Entecavir (1 mg daily) or tenofovir are the preferred treatment options for patients with decompensated HBV cirrhosis, and patients should be closely monitored for drug tolerability and rare side effects like lactic acidosis or kidney dysfunction, as recommended by the European Association for the Study of the Liver 5, 6.