Sections View Full Chapter Figures Tables Videos Annotate Full Chapter Figures Tables Videos Supplementary Content + Download Section PDF Listen ++ For further information, see CMDT Part 16-11: Cirrhosis + Key Features Download Section PDF Listen +++ ++ 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 Download Section PDF Listen +++ ++ 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 Download Section PDF Listen +++ ++ 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 Download Section PDF Listen +++ ++ 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