title: Problems with using total serum bilirubin as a criterion for phototherapy in extremely low-birthweight infants.
abstract: BACKGROUND
  Despite the early use of phototherapy and exchange transfusion in premature infants based on total serum bilirubin (TSB), the reemergence of kernicterus has been reported. The aim of this study was to assess the validity of using TSB as the criterion for phototherapy in extremely low-birthweight infants (ELBWI).
  
  
  METHODS
  We reviewed the medical charts of 43 ELBWI admitted to hospital between January 2009 and December 2010, and analyzed the relationship between TSB and unbound bilirubin (UB).
  
  
  RESULTS
  No infant underwent exchange transfusion or developed acute bilirubin encephalopathy. There was a significant correlation between TSB and UB measured immediately before phototherapy during the first 7 days of life (r = 0.657, P < 0.001), but none thereafter (r = 0.120, P = 0.213). Thirty-seven percent of infants who underwent phototherapy during the first 7 days of life had suprathreshold USB but subthreshold TSB, whereas this rose to 97% thereafter.
  
  
  CONCLUSIONS
  No correlation was observed between TSB and UB in ELBWI after the first 7 days of life, and almost all phototherapy sessions were initiated based on the UB criterion, even though TSB was below the accepted threshold. UB may be high if jaundice is evaluated solely on the basis of TSB.
authors.affiliation: Department of Neonatology, Gunma Children's Medical Center, Gunma, Japan.
authors.forename: Kenji
authors.initials: K
authors.lastname: Ichinomiya
authors.forename: Fumitaka
authors.initials: F
authors.lastname: Inoue
authors.forename: Aya
authors.initials: A
authors.lastname: Koizumi
authors.forename: Takahiro
authors.initials: T
authors.lastname: Inoue
authors.forename: Toru
authors.initials: T
authors.lastname: Fujiu
authors.forename: Kenichi
authors.initials: K
authors.lastname: Maruyama
mesh_terms: D001663:Bilirubin / Q000097:blood*; D005260:Female; D006801:Humans; D051556:Hyperbilirubinemia, Neonatal / Q000628:therapy*; D052577:Infant, Extremely Low Birth Weight; D007231:Infant, Newborn; D008297:Male; D010789:Phototherapy; D012189:Retrospective Studies
chemical_list: D001663:Bilirubin
keywords: extremely low-birthweight infant; neonatal hyperbilirubinemia; phototherapy; total serum bilirubin; unbound bilirubin