Table 2—

Grading of severity of hepatopulmonary syndrome#

StagePA–a,O2¶,§ mmHgPa,O2+,§ mmHg
Mild≥15≥80
Moderate≥15<80–≥60
Severe≥15<60–≥50
Very severe≥15<50 (<300 on 100% O2)

  • PA–a,O2: alveolar–arterial oxygen tension difference

  • Pa,O2: arterial oxygen tension

  • #: all with positive contrast-enhanced echocardiography

  • : normal range 4–8 mmHg

  • +: normal range 100–80 mmHg (breathing room air at rest and at sea level) 14

  • §: for patients aged >64 yrs, a cut-off value for PA–a,O2 of ≥20 mmHg and Pa,O2 of <70 mmHg can be recommended 14

  • 1 mmHg=0.133 kPa