What is hepatopulmonary syndrome (HPS)?

From the Guidelines

Hepatopulmonary syndrome (HPS) is a condition characterized by abnormal oxygenation due to vascular changes in the lungs that occur as a result of liver disease, involving the triad of liver disease, intrapulmonary vascular dilations, and impaired oxygenation. The primary characteristics of HPS include liver disease, intrapulmonary vascular dilations, and impaired oxygenation, with patients typically presenting with shortness of breath, particularly when standing (platypnea), and low oxygen levels that worsen in an upright position (orthodeoxia) 1.

Key Features of HPS

• Liver disease
• Intrapulmonary vascular dilations
• Impaired oxygenation
• Shortness of breath, particularly when standing (platypnea)
• Low oxygen levels that worsen in an upright position (orthodeoxia) The condition occurs because liver dysfunction leads to increased production of vasodilators like nitric oxide, causing pulmonary vessels to dilate abnormally, creating a ventilation-perfusion mismatch where blood passes through the lungs too quickly to be properly oxygenated 1.

Treatment of HPS

• The primary treatment for hepatopulmonary syndrome is liver transplantation, which can reverse the pulmonary vascular abnormalities in most patients 1.
• Before transplantation, supplemental oxygen therapy is used to manage hypoxemia 1.
• There are no effective medical therapies that consistently improve oxygenation, though some patients may receive pentoxifylline or garlic preparations with limited evidence of benefit 1. Early recognition is important as the presence of hepatopulmonary syndrome may prioritize patients for liver transplantation, particularly those with severe HPS, who have a median survival of less than 12 months 1.

From the Research

Definition and Characteristics of Hepatopulmonary Syndrome (HPS)

• Hepatopulmonary syndrome (HPS) is defined as the triad of liver disease, intrapulmonary vascular dilatation, and abnormal gas exchange 2, 3, 4.
• It is found in 10-32% of patients with liver disease 2.
• HPS is characterized by pulmonary vascular dilatations and shunts, resulting in impaired gas exchange 4.

Diagnosis and Prevalence

• HPS is identified in as many as 20% of patients who are evaluated for orthotopic liver transplantation (OLT) 3.
• The syndrome is often under-recognized as a vascular complication of cirrhosis and portal hypertension 3.

Treatment and Management

• Liver transplantation is the only known cure for HPS 2, 3, 4.
• Supplemental oxygen can improve oxygenation in patients with HPS 3.
• Other treatment options, such as transtracheal oxygen therapy, may be considered for severe cases 5.
• Transjugular intrahepatic portosystemic shunts (TIPS) placement may be used as a bridge towards transplantation in patients with severe hypoxemia 6.

Complications and Outcomes

• Severe posttransplant hypoxemia is a complication that can occur in patients with HPS, carrying a 45% mortality 2.
• The use of specific strategies targeting the underlying physiologic abnormalities in HPS can improve management of this complication 2.
• Outcomes in patients with HPS have been significantly better since the implementation of the model for end-stage liver disease (MELD) standard exception policy 4.