Diagnostic Criteria and Treatment Options for Hepatopulmonary Syndrome (HPS)

Diagnostic Criteria

HPS should be suspected in patients with chronic liver disease who present with symptoms such as tachypnea, polypnea, digital clubbing, and/or cyanosis 1
The syndrome occurs in 10-30% of patients with cirrhosis and portal hypertension 2
HPS can also occur in patients with non-cirrhotic portal hypertension, congenital portosystemic shunts, or even acute/chronic hepatitis without significant liver dysfunction 2, 3
Pulse oximetry in upright position (SpO2 <96% is highly sensitive for HPS) 4
Arterial blood gas (ABG) analysis showing PaO2 <80 mmHg or Alveolar-arterial oxygen gradient (P[A-a]O2) ≥15 mmHg on room air (≥20 mmHg in patients ≥65 years) 4, 2
Contrast-enhanced (microbubble) echocardiography is the most sensitive test for documenting intrapulmonary vascular dilatations 4
Technetium-labeled macroaggregated albumin (MAA) lung perfusion scan showing shunt fraction >6% can be used as an alternative 4, 3

The American Association for the Study of Liver Diseases recommends liver transplantation as the only curative therapy for HPS 3
Liver transplantation triples 5-year survival in HPS patients regardless of baseline disease severity 3
HPS is generally reversible after transplantation 3
For patients with severe HPS (PaO2 <50 mmHg), median survival without transplantation is less than 12 months in adults 3
Closure of congenital portosystemic shunts should be considered as an alternative to transplantation for non-cirrhotic causes of HPS 3

Five-year survival rate is only 23% in untransplanted HPS patients versus 63% in matched cirrhotic patients without HPS 5
Survival is significantly worse in patients with HPS and PaO2 <50 mmHg at diagnosis 5

Regular screening with room air pulse oximetry in upright position for patients with portal hypertension 3
Assessment of functional capacity and oxygen requirements during physical activity 3

Hepatopulmonary syndrome (HPS) is classified based on the severity of hypoxemia, with four categories determined by arterial oxygen levels: mild (PaO2 ≥80 mmHg), moderate (PaO2 60-79 mmHg), severe (PaO2 50-59 mmHg), and very severe (PaO2 <50 mmHg) 6, 7
The European Association for the Study of the Liver recommends that HPS diagnosis is based on a triad of components, including presence of liver disease or portal hypertension, intrapulmonary vascular dilatations (IPVD), and arterial oxygenation abnormalities 7, 8

The American Association for the Study of Liver Diseases suggests that the severity classification of HPS has significant implications for prognosis, with a five-year survival rate of only 23% in untransplanted HPS patients versus 63% in matched cirrhotic patients without HPS 7
Patients with severe HPS (PaO2 <60 mmHg) should be evaluated for liver transplantation, as it significantly improves survival, according to the American Association for the Study of Liver Diseases 6
The Model for End-Stage Liver Disease (MELD) exception points are granted to patients with severe HPS to prioritize them for transplantation, as recommended by the United Network for Organ Sharing 6
Pre-liver transplant room-air PaO2 ≤44.0 mmHg is associated with increased post-liver transplant mortality, highlighting the importance of close monitoring and timely transplantation, as suggested by the European Society of Gastrointestinal and Abdominal Radiology 6