The hepatopulmonary syndrome is suspected in any patient with known liver disease who reports dyspnea (particularly platypnea).

These abnormal phenomena are usually seen in chronic bronchitis, asthma, hepatopulmonary syndrome, and acute pulmonary edema.

The hepatopulmonary syndrome results from the formation of microscopic intrapulmonary arteriovenous dilatations in patients with both chronic and acute liver failure.

Hepatopulmonary syndrome - blood bypassing the normal lung circulation (shunting), leading to cyanosis and dyspnea (shortness of breath), characteristically worse on sitting up.

With liver transplantation, the 5 year survival rate is 76%, which is comparable to patients who undergo liver transplants who do not suffer from hepatopulmonary syndrome.

Platypnea is due to either hepatopulmonary syndrome or an anatomical cardiovascular defect increasing positional right-to-left shunting (bloodflow from the right to the left part of the circulatory system).

In medicine, hepatopulmonary syndrome is a syndrome of shortness of breath and hypoxemia (low oxygen levels in the blood of the arteries) caused by vasodilation (broadening of the blood vessels) in the lungs of patients with liver disease.