Renal function in infants with hyperbilirubinemia.

A total of 45 infants were studied on the fourth or fifth day of life: 13 term and 10 pre-term infants with serum bilirubin levels ranging between 257 and 390 mumol/l were compared with 12 term and 10 pre-term infants with serum bilirubin levels below 195 mumol/l. The groups did not differ with regard to mean gestational age or mean post-natal age. GFR and CPAH were determined with the single injection clearance method and ability to excrete Na+ was determined following an oral loading of sodium chloride. GFR was lower in infants with hyperbilirubinemia and correlated negatively to the highest recorded serum bilirubin value. CPAH was similar in hyperbilirubinemic infants and controls. The urinary sodium excretion was significantly higher in infants with hyperbilirubinemia.