The hepatopulmonary syndrome is characterized by defects in oxygenation due to pulmonary abnormalities associated with chronic liver disease. Dyspnea and hypoxia may be marked and often worsen in the upright position. Gross dilatation of the precapillary and capillary vessels occurs with ventilation-perfusion mismatch.
There are no signs and symptoms, or hallmarks of the hepatopulmonary syndrome on physical examination. However, the presence of spider nevi, digital clubbing, cyanosis, and severe hypoxemia (partial pressure of oxygen <60 mm Hg [8.0 kPa]) suggests the possibility of the hepatopulmonary syndrome. If the partial pressure of oxygen decreases by 5% or more or by 4 mm Hg [0.5 kPa] or more when the patient moves from a supine to an upright position (called orthodeoxia), or if the patient has worsening dyspnea (platypnea) related to further ventilation–perfusion mismatch, then hepatopulmonary syndrome may be the problem. The chest radiograph is frequently nonspecific, often showing a mild interstitial pattern in the lower lung that may reflect the existence of diffuse pulmonary vascular dilation.
Currently, no effective medical therapies for the hepatopulmonary syndrome exist, and liver transplantation is the only successful treatment.