Abstract
Recent investigations on the metabolism of bilirubin suggest that free or unbound bilirubin which is not bound to plasma albumin, easily moves into the brain and results in brain damage. The concentration of unbound bilirubin was compared with that of total bilirubin in 19 cases with hyperbilirubinemia. The concentration of unbound bilirubin in the plasma was measured by the modified Jacobsen's method using peroxidase. The following results and conclusions were obtained by this study : 1) There were no close correlations between the concentrations of unbound bilirubin and that of total bilirubin. 2) In mature neonates, although the concentration of total bilirubin in the plasma exceeded 20mg%, that of unbound bilirubin remained at low levels except in one case. 3) On the contrary, in immature neonates, the concentration of unbound bilirubin remained at high levels, while the amount of total bilirubin was under 15mg%. 4) The unbound bilirubin concentration as well as that of the total bilirubin in the plasma was effectively reduced by phototherapy. In the indication of exchange blood transfusion for severe jaundice in neonates in decided on a basis of the measurement of the concentration of unbound bilirubin, the number of early exchange blood transfusion will be reduced.
