KINETICS OF OXYGEN ABSORPTION IN AN EXPOSED FILM OF WHOLE BLOOD

The Higbie Penetration theory is used to estimate the rate at which oxygen will be absorbed in a surface film of whole blood exposed for a short time to an oxygen rich atmosphere. The physiological assumptions are that transport of oxygen occurs by diffusion and that absorption of oxygen by haemoglobin is instantaneous. Even this simplified model results in a non-linear partial differential equation whose solution depends on both the oxygen concentration in the ambient atmosphere and in the bulk of the blood. The solutions show that the presence of red cells greatly enhance the rate of oxygen transport above that of pure diffusion when the film is exposed to an atmosphere in which the concentration of oxygen is about equal to or less than the concentration of oxygen in air. In practical use in the operating theatre the oxygenators are operated at concentrations of oxygen in excess of this and respiration into the blood is by a diffusion mechanism only. © 1969.