The gaseous composition of the blood has been determined in cardiac cavities and major vessels in 180 practically healthy individuals aged from 1 to 30 years, during diagnostic catheterization of the heart. Physiological norms of gaseous composition of the blood in cardiac cavities and in the major blood vessels have been determined. Blood saturation with oxygen in the identical cardiac cavities and the major blood vessels are the same in men and women. The arterial blood having oxygenation below 93% is considered hypoxaemic. Normal figures of oxygenation for venous blood are from 75-84%. Exponential decrease of blood oxygenation with age (arterial and mixed venous) is roughly the same, due to this the arteriovenous difference of oxygenation at rest remains constant and is roughly equal to 20%. Minimum arterio-venous difference in oxygenation is 10%, maximum 40%.
Adolescent Adult