[Effect of hyperoxia on the oxygen-transport properties of the blood]

In 9 normal test subjects, aged 19-32, pO2, pCO2 and pH of arterial and venous blood were measured. The curve of oxyhemoglobin dissociation during 20 min inhalation of a 95% O2 containing mixture was analyzed. The studies demonstrate that during hyperoxia there is a shift to the left of the dissociation curve in native blood and standard curve (i.e. normalized to pH 7.4). This shift of the curve of oxyhemoglobin dissociation indicating an increase in hemoglobin affinity for oxygen seems to be one of the factors responsible for an increase in the pO2 arteriovenous difference and a much lower increment of venous pO2 than that of arterial pO2.