Arterial and Venous Blood Gases

A Blood gas test or blood gas analysis tests blood to measure blood gas tension values. It also measure blood PH ,and the level and  base excess of bicarbonate.


Blood Gas Component Arterial  Venous 
PH 7.35-7.45 7.31-7.41
PO2 80-100mm Hg 35-40mm Hg
PCO2 35-45 mm Hg 41-51mm Hg
HCO3 22-26 mEq/l or mmol/L 22-26 mEq/L or mmol/L
Base Excess (BE) -2 to +2 meq/L or mmol/L -2 to +2 mEq/L or mmol/L
O2 saturatio 95%–100% 68%-77%