Hypoxemia in liver cirrhosis

Hypoxaemia is observed in almost 30 per cent of patients with cirrhosis of the liver, irrespective of the cause of cirrhosis. Two main physiopathological mechanisms can be described: hypoxaemia may be secondary to intrapulmonary vascular abnormalities or due to a regional disequilibrium of the ventilation/perfusion ratio. In the first case, the severity of hypoxaemia often requires complex and invasive investigations, while in the second case, by far the most frequent, hypoxaemia is moderate, usually asymptomatic and in practice only needs a few investigations.