Hypoxemia in patients with liver cirrhosis.

Chronic liver disease is often accompanied by alterations in the pulmonary and cardiovascular systems as demonstrated by hypoxemia, hyperkinetic circulation and impaired pulmonary and systemic vascular resistance. In some patients these abnormalities are due to ventilation-perfusion imbalance and/or intrapulmonary shunting. Although the pathogenesis of these disturbances is unknown it can be hypothesized that vasodilating substances might bypass the liver and give rise to such changes in intrapulmonary vessels. The normalization of pulmonary perfusion after liver transplantation suggests a direct functional relationship between the liver and the lungs--a "hepatopulmonary syndrome"--similar to the functional renal failure widely known as the hepatorenal syndrome.