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Biochemical Measurement of Neonatal Hypoxia
13:13

Biochemical Measurement of Neonatal Hypoxia

Published on: August 24, 2011

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Bilirubin production and hour-specific bilirubin levels

V K Bhutani1, R J Wong1, H J Vreman1

  • 1Division of Neonatal and Developmental Medicine, Department of Pediatrics, Stanford University School of Medicine, Stanford, CA, USA.

Journal of Perinatology : Official Journal of the California Perinatal Association
|April 17, 2015
PubMed

Insights

High bilirubin production contributes to elevated total bilirubin (TB) in newborns. Impaired bilirubin elimination may cause severe hyperbilirubinemia in infants without increased bilirubin production.

Area of Science:

  • Neonatal Medicine
  • Pediatric Gastroenterology
  • Neonatal Hyperbilirubinemia

Background:

  • Total bilirubin (TB) levels in newborns are influenced by production and elimination.
  • End-tidal carbon monoxide (ETCOc) is a non-invasive marker of bilirubin production.
  • Understanding the drivers of hyperbilirubinemia is crucial for timely intervention.

Purpose of the Study:

  • To evaluate the contribution of increased bilirubin production to hour-specific TB levels in late preterm and term infants.
  • To identify infants with impaired bilirubin elimination despite normal bilirubin production.

Main Methods:

  • Post hoc analysis of a cohort of 641 term and late preterm infants.
  • Concurrent measurement of ETCOc and TB at 30±6 hours of age.
  • Follow-up TB measurements up to 168 hours of age.

Main Results:

  • Approximately 80% of infants in the high-risk TB zone exhibited increased bilirubin production (ETCOc ≥1.7 ppm at 30±6h).
  • Increased bilirubin production was also observed in 42% and 32% of infants in intermediate and low-risk zones, respectively.
  • One infant with TB <40th percentile and normal ETCOc developed severe hyperbilirubinemia, suggesting impaired elimination.

Conclusions:

  • Infants in the high-risk quartile of the hour-specific bilirubin nomogram demonstrate higher mean bilirubin production.
  • Severe hyperbilirubinemia in infants without increased bilirubin production may indicate impaired bilirubin elimination.
Abstract

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