Table 2. Diagnostic criteria and staging for hepatopulmonary syndrome
PA-a,O2# mmHgPa,O2 mmHg
Moderate≥15≥60 to <80
Severe≥15≥50 to <60
Very severe≥15<50
  • PA–a,O2: alveolar–arterial oxygen tension difference; Pa,O2: arterial oxygen tension. #: other proposed cut-off values for PA–a,O2are ≥20 mmHg and at the same as the age-related expected value; : Pa,O2<70 mmHg is used at some transplant centres as a diagnostic criterion.