PaO2 mm Hg = SaO2%

• 20 = 35, lowest tolerated

• 26 = 50

• 40 = 75

• 55 = 88 medicare standard for continuous O2 Tx.

60 = 90 "knee of O2-Hb dissociation curve; hypoxic drive and erythrocytosis are expected below this level

• 80 = 95 low normal arterial range

• 100 = 97 upper normal arterial range