Phenolsulfonphthalein binding capacity ofserum in newborn infants

The dye (PSP) binding capacity (D.B.C.) in serum of full-term and premature infantswas investigated. Normal infants and those with hemolytic and nonhemolytic hyperbilirubinemia were studied. Prematurity and hemolytic disease were shown to be factors associated with the greatest reduction in D.B.C. of serum. Infusion of albumin into two premature babies with nonhemolytic hyperbilirubinemia resulted in a rise of D.B.C. with only a transient elevation of bilirubin. The relationship of the D.B.C. to susceptibility to kernicterus in premature and full-term infants with hemolytic and nonhemolytic hyperbilirubinemia is discussed.