Hepatopulmonary syndrome
Hepatopulmonary syndrome is intrapulmonary vascular dilatation and right-to-left shunting that develops in patients with portal hypertension, producing hypoxemia with the hallmark signs of platypnea and orthodeoxia. Contrast-enhanced echocardiography confirms the shunt, and liver transplantation is the only effective treatment.
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What this article covers
- Overview
Definition: hepatopulmonary syndrome (HPS) is dilation of the intrapulmonary vasculature occurring in patients with portal hypertension, which produces right-to-left shunting of blood and hypoxemia.
- Epidemiology
Occurs in the setting of portal hypertension, most commonly from cirrhosis of any cause, and can also arise from noncirrhotic portal hypertension.
- Risk factors
Cirrhosis with portal hypertension: the dominant substrate, regardless of the underlying cause of liver disease.
- Pathophysiology
Portal hypertension drives pulmonary vasodilation: the mechanism links liver disease and portal pressure to abnormal dilation of the pulmonary capillary and precapillary vasculature.
- Clinical features
Platypnea: dyspnea that worsens when the patient moves from lying to sitting or standing, the classic positional symptom of HPS.
- Differential diagnosis
Portopulmonary hypertension: dyspnea on exertion in a patient with cirrhosis and portal hypertension, but driven by elevated pulmonary arterial pressure and right-sided heart pressures rather than…
- Diagnosis
Establish the diagnosis with the triad of portal hypertension, an abnormality of arterial oxygenation, and evidence of intrapulmonary vascular dilatation.
- Management
Start supplemental oxygen for symptomatic hypoxemia: titrate nasal cannula or higher-flow oxygen to keep resting oxygen saturation adequate; this treats the hypoxemia symptomatically but does not alter the underlying shunt.
- Complications
Severe, refractory hypoxemia: progressive intrapulmonary shunting can produce oxygen saturations low enough to limit activity and increase perioperative risk.
- Prognosis
Liver transplantation reverses the syndrome: hypoxemia typically resolves after successful transplantation, and transplantation improves survival compared with the natural history of untreated HPS.
- Prevention
No primary prevention exists for hepatopulmonary syndrome itself; prevention is directed at the causes of portal hypertension, chiefly management of the underlying liver disease to prevent progression to Cirrhosis and portal hypertension.
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Hepatocellular carcinoma is a primary liver cancer that arises almost exclusively in cirrhosis and can be diagnosed non-invasively when multiphase CT or MRI shows arterial-phase hyperenhancement with portal-venous washout in a lesion at least 1 cm. Treatment is stratified by tumor burden, liver function, and vascular or extrahepatic spread, ranging from resection or ablation through transplantation and transarterial chemoembolization to systemic atezolizumab-bevacizumab for advanced disease.