Simulation of bilirubin detoxification in the newborn using an extracorporeal bilirubin oxidase reactor.

Jaundice, which is characterized by an excessive accumulation of bilirubin in the blood and tissues, occurs in 13% of newborns. The common treatments for neonatal jaundice are phototherapy and blood exchange transfusion. A novel approach using an extracorporeal blood filter containing immobilized bilirubin oxidase was recently proposed to detoxify jaundiced blood, and a prototype device markedly reduced serum bilirubin in genetically jaundiced Gunn rats. The primary toxicologic effect in that study was a 20% reduction in red blood cell count. Using a compartmental model for bilirubin metabolism, a mathematical simulation of the extracorporeal treatment's ability to reduce serum bilirubin levels in jaundiced infants is presented. Using a 10-mL reactor volume containing immobilized bilirubin oxidase, the simulation predicts a 32 to 65% decrease in plasma bilirubin concentration over a 4-h treatment for a 2 kg preterm hyperbilirubinemic newborn. In addition, a new approach to altering support material has essentially eliminated red blood cell lysis in vivo using Gunn rats and in vitro using adult blood.