Hepatopulmonary Syndrome

Hepatopulmonary syndrome (HPS) is a liver-induced pulmonary vascular abnormality that can cause severe arterial hypoxemia. Hypoxemia is due to ventilation-perfusion mismatching, diffusion-perfusion defects, and anatomic shunts. Circulating mediators emanating from the diseased liver have been implicated to cause intrapulmonary vascular dilatation, the hallmark of HPS. HPS has been associated with any type of liver disease or cause of portal hypertension. Aside from supplemental oxygen, medical therapies are of limited benefit in improving hypoxemia due to HPS. Remarkably, liver transplantation resolves the syndrome in most cases and is considered the treatment of choice.