Last update:
29-Nov-2011

Lung complications may occur as a result of hepatic disease from any cause and they represent a highly heterogeneous group of conditions. The hepatopulmonary syndrome (HPS) is characterized as the triad of liver disease, pulmonary gas exchange abnormalities leading to arterial deoxygenation (ΡaΟ₂ <80 mmHg at room air and alveolar-arterial gradient >15 mmHg) and evidence of intrapulmonary vascular dilatation. Although a number of different pathogenetic mechanisms are likely to be involved, chronic liver dysfunction may cause pulmonary manifestations because of alterations in the production or clearance of circulating cytokines and other mediators. The role is reviewed of the three diagnostic imaging modalities in current use, namely, contrast-enhanced echocardiography, perfusion lung scanning and pulmonary arteriography, which identify the presence of intrapulmonary vascular abnormalities. Early recognition of HPS may be challenging, but is crucial both for formulating a meaningful differential diagnosis and for avoiding severe sequelae and irreversible damage. Liver transplantation is considered to be the definitive treatment of HPS, often resulting in successful reversal of hypoxemia. Trials have been conducted, however, of other forms of treatment, such as the use of pharmacological agents and radiological intervention. Screening for HPS with the use of arterial blood gases is recommended in patients with chronic liver disease who report dyspnea or who are candidates for liver transplantation.

Key words: Cirrhosis, Hepatopulmonary syndrome, Liver transplantation.