PA-a,O2# mmHg | Pa,O2¶ mmHg | |
Mild | ≥15 | ≥80 |
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.