title: Yield of recommended blood tests for neonates requiring phototherapy for hyperbilirubinemia.
abstract: BACKGROUND
  Hyperbilirubinemia of the newborn is common. Rarely is an underlying disease other than physiologic hyperbilirubinemia considered the cause of high bilirubin levels. Some of the laboratory tests recommended by the American Academy of Pediatrics are expensive and do not always lead to diagnosis.
  
  
  OBJECTIVE
  To evaluate the efficacy of standard laboratory tests performed on newborn infants requiring phototherapy for hyperbilirubinaemia.
  
  
  METHODS
  We conducted a retrospective chart review that included neonates born during a 6 month period with birth weight 2500 g treated with phototherapy for hyperbilirubinemia (n = 282) according to published guidelines. The main outcome measures were primary and maximal bilirubin values (mg/dl), time to jaundice (in days), the number of bilirubin tests undertaken and whether the patient showed abnormal functioning, and the number of days in follow-up.
  
  
  RESULTS
  Thirty-three neonates (11.7%) were positive in at least one laboratory test (defined as "Abnormal" in our study), 45.5% of whom met the criteria for phototherapy during the first 48 hours of life. Among the newborns who were negative for all laboratory tests (defined as "Normal"), only 6.8% met phototherapy criteria within their first 48 hours of life (P < 0.001). In the Normal group there was a consistent decrease in total serum bilirubin values shortly after phototherapy was begun, while the Abnormal group presented an increase in serum bilirubin values during the first 12 hours of phototherapy. None of the infants had conjugated (direct) hyperbilirubinemia during the study period.
  
  
  CONCLUSIONS
  Most neonates presenting with a laboratory identifiable etiology for hyperbilirubinemia (i.e., hemolysis) can be distinguished from those who test negative, mainly based on the timing of presentation and response to phototherapy. A more meticulous selection of patients and reduction in the magnitude of routine laboratory testing can safely reduce discomfort to infants with hyperbilirubinemia as well as costs.
authors.affiliation: Department of Neonatology, Soroka University Medical Center, Beer Sheva, Israel.
authors.forename: Itay
authors.initials: I
authors.lastname: Besser
authors.forename: Zvi H
authors.initials: ZH
authors.lastname: Perry
authors.forename: Oded
authors.initials: O
authors.lastname: Mesner
authors.forename: Ehud
authors.initials: E
authors.lastname: Zmora
authors.forename: Asaf
authors.initials: A
authors.lastname: Toker
mesh_terms: D005260:Female; D006403:Hematologic Tests / Q000379:methods / Q000706:statistics & numerical data; D006801:Humans; D051556:Hyperbilirubinemia, Neonatal / Q000097:blood* / Q000175:diagnosis / Q000628:therapy*; D007231:Infant, Newborn; D008297:Male; D008403:Mass Screening / Q000379:methods / Q000706:statistics & numerical data; D010789:Phototherapy / Q000379:methods*; D011237:Predictive Value of Tests; D012189:Retrospective Studies