Hepatopulmonary Syndrome

Characteristic triad

• Chronic liver disease

• Increased alveolar-arterial gradient on room air

• Intrapulmonary vascular dilatations or arteriovenous communications that result in a right-to-left intrapulmonary shunt

Dyspnea (platypnea) and arterial deoxygenation (orthodeoxia) are greater in the upright position than in the recumbent position

Suspect hepatopulmonary syndrome in a cirrhotic patient with a pulse oximetry level ≤ 96%

Elevated levels of von Willebrand factor antigen in affected patients suggests that endothelial dysfunction may have role

Contrast-enhanced echocardiography is a sensitive screening test for detecting pulmonary vascular dilatations, whereas macroaggregated albumin lung perfusion scanning is more specific and may be used to confirm the diagnosis

High-resolution CT may be useful for detecting dilated pulmonary vessels that may be amenable to embolization

Medical therapy has been disappointing

However, intravenous methylene blue, oral garlic powder, oral norfloxacin, and mycophenolate mofetil may improve oxygenation by inhibiting nitric oxide–induced vasodilatation and angiogenesis

Pentoxifylline may prevent hepatopulmonary syndrome by inhibiting production of tumor necrosis factor

Long-term oxygen therapy is recommended for severely hypoxemic patients

Hepatopulmonary syndrome may reverse with liver transplantation

Postoperative morbidity and mortality from severe hypoxemic respiratory failure are increased when the preoperative arterial oxygen tension is < 44 mm Hg (5.9 kPa) or with substantial intrapulmonary shunting

In cases confirmed by right-sided heart catheterization, treatment with the following may reduce pulmonary hypertension and thereby facilitate liver transplantation

• Epoprostenol, iloprost, or treprostinil (the latter two are easier to administer)

• Bosentan (no longer used because of potential hepatotoxicity), ambrisentan, or macitentan

• Sildenafil, tadalafil or vardenafil

• Selexipag

• Riociguat

Beta-blockers worsen exercise capacity and are contraindicated

Calcium channel blockers should be used with caution because they may worsen portal hypertension

Liver transplantation is contraindicated in patients with moderate to severe pulmonary hypertension (mean pulmonary pressure > 35 mm Hg)

Transjugular intrahepatic portosystemic shunt (TIPS) may provide palliation in patients with hepatopulmonary syndrome awaiting transplantation