Oxygen Content

Calculate the oxygen content given the P_aO₂, S_aO₂, and the hemoglobin (Hgb).

Input Hemoglobin		gm/dL
Input S_aO₂		%
Input P_aO₂		torr



Oxygen Content	=

The equation is:

C_aO₂ = 1.36 * Hgb *	S_aO₂	+ 0.0031 * P_aO₂

	100

The constant, 1.36, is the amount of oxygen (ml at 1 atmosphere) bound per gram of hemoglobin. The exact value of this constant varies from 1.34 to 1.39, depending on the reference and the way it is derived. The constant 0.0031 represents the amount of oxygen dissolved in plasma. The dissolved oxygen term is generally small relative to the hemoglobin-bound oxygen, but becomes significant at very high P_aO₂ (as in a hyperbaric chamber) or in severe anemia.

Created: January 7, 2000
Revised: October 19, 2000