PO2

If FiO2 is < =49 % or less then choose the worst PaO2 from any of the blood gases collected according to Apache II General Collection Guidelines.

If FiO2 is >= 50% then choose the worst AaDO2

• PO2 Partial Pressure of Oxygen
• PaO2 Partial Pressure of Oxygen in Arterial Blood

• an element of Arterial Blood Gas

• See APACHE Scoring table
• See FiO2 table