Hepatopulmonary syndrome

Abstract Hepatopulmonary syndrome (HPS) is a pulmonary vascular complication of chronic liver disease or portal hypertension. It is characterized by arterial hypoxemia resulting from intrapulmonary vascular dilatations (IPVDs). The hallmark pathophysiological mechanisms include ventilation–perfusion mismatch, diffusion defects, and intrapulmonary shunting caused by increased production of vasodilators such as nitric oxide and inflammatory cytokines. Clinically, progressive HPS presents with dyspnea, cyanosis, and the characteristic features of platypnea and orthodeoxia. Screening with pulse oximetry and confirmation using contrast-enhanced echocardiography or technetium-99 m macroaggregated albumin scan are essential for diagnosis. The disease is graded based on the PaO 2 levels and alveolar–arterial oxygen gradient. While supportive oxygen therapy may improve symptoms temporarily, medical therapies remain largely ineffective. Liver transplantation is the only definitive treatment that reverses hypoxemia and improves long-term survival. Careful perioperative management, including the use of inhaled nitric oxide to manage posttransplant hypoxemia, is crucial for favorable outcomes. Awareness and early recognition of HPS are vital for timely referral and optimal transplant planning in pediatric patients with chronic liver disease.