Calculation of oxygen saturation of mixed venous blood in infants.

A retrospective survey of the heart catheterizations of twenty-two children below the age of three years was carried out in order to evaluate different formulae for calculation of the oxygen saturation in mixed venous blood (MVB) from the oxygen saturation in blood from the superior caval vein (SVC) and inferior caval vein (IVC). The formula MVB = (3SVC + IVQ/4 was found satisfactory, also during halothane anaesthesia.