Blood Gases: Arterial or Venous?

Abstract

The determination of "blood gases" in the current clinical vernacular means the measurement of pH, partial pressure of carbon dioxide (PCO₂), and partial pressure of oxygen (PO₂) in fresh samples of whole blood drawn without exposure to air and usually protected from glycolysis and coagulation by prompt cooling and the addition of heparin. With the use of the Henderson–Hasselbalch equation, the concentration of bicarbonate in the plasma can also be calculated from the pH and PCO₂, and this value is usually included with the report of the blood gases.These data have found increasing . . .