Hepatopulmonary Syndrome

Key Features

• 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

Clinical Findings

• 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

Diagnosis

• 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

Treatment

• 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

• β-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