Hyperbilirubinemia/Jaundice — Laboratory Studies TcB Interpretation — Clinical Pathway: All Settings

Neonates with Hyperbilirubinemia/Jaundice Clinical Pathway

Laboratory Studies and Transcutaneous Bilirubin (TcB) Interpretation

Laboratory Studies

Bilirubin Measurement
  • Serum:
    • TSB = Bilirubin Unconjugated (BU) + Bilirubin Conjugated (BC)
  • Transcutaneous:
    • Dräger, Philips BiliChek
Direct Antiglobulin Test (DAT) Helps identify infants at risk for hyperbilirubinemia from hemolysis
CBC, Peripheral Smear Reticulocyte Count
  • Phototherapy required
  • Concern for hemolysis
BMP Concern for significant dehydration
CMP Concern for elevated conjugated bilirubin, ICU Care required
Albumin Consider if TSB near exchange transfusion level
Type and Cross Consider when TSB is within 2 points of Exchange Threshold

Transcutaneous Bilirubin (TcB) Interpretation

  • Reliable screening test, a good correlation between TcB and TSB
  • TSB is usually within 3 mg/dL of the TcB if TSB < 15 mg/dL
  • For infants with greater skin melanin, the tool may underestimate or overestimate measurement
    • Philips BiliChek underestimates by 1-2 mg/dL, Dräger-JM overestimates by 0.7-2.5 mg/dL
  • Measure TSB if TcB is within 3 mg/dL of the phototherapy threshold or > 15. See the quick reference table below.

Reference Guides for Checking TSB Based on TcB Bilirubin Reading by Hour of Life

Table data is meant for quick reference or support of initiating standing orders for TcB monitoring, most precise indication for obtaining serum bilirubin is if TcB is within 3 mg/dL of hour specific photo threshold.

No Additional Neurotoxicity Risk Factors Outside Gestational Age

Age in Hours ≥ 35 wks GA ≥ 36 wks GA ≥ 37 wks GA ≥ 38 wks GA ≥ 39 wks GA ≥ 40 wks GA
Up to 12 ≥ 2 ≥ 4 ≥ 4.5 ≥ 5 ≥ 5.5 ≥ 6
≥ 12 up to 24 ≥ 5.5 ≥ 6 ≥ 6.5 ≥ 7 ≥ 7.5 ≥ 8
≥ 24 up to 36 ≥ 7.5 ≥ 8 ≥ 8.5 ≥ 9 ≥ 9.5 ≥ 10
≥ 36 up to 48 ≥ 9.5 ≥ 10 ≥ 10.5 ≥ 11 ≥ 11.5 ≥ 12
≥ 48 up to 60 ≥ 11 ≥ 11.5 ≥ 12 ≥ 13 ≥ 13.5 ≥ 14
≥ 60 up to 72 ≥ 12.5 ≥ 13 ≥ 13.5 ≥ 14 ≥ 14.5 ≥ 15
≥ 72 up to 84 ≥ 14 ≥ 14.5 ≥ 15 ≥ 15 ≥ 15 ≥ 15
≥ 84+ ≥ 15 ≥ 15 ≥ 15 ≥ 15 ≥ 15 ≥ 15

One or More Additional Neurotoxicity Risk Factors in Addition to Gestational Age

Age in Hours ≥ 35 wks GA ≥ 36 wks GA ≥ 37 wks GA ≥ 38 wks GA
Up to 12 ≥ 2 ≥ 2.5 ≥ 3 ≥ 3.5
≥ 12 up to 24 ≥ 4 ≥ 4.5 ≥ 5 ≥ 5.5
≥ 24 up to 36 ≥ 6 ≥ 6.5 ≥ 7 ≥ 7.5
≥ 36 up to 48 ≥ 7.5 ≥ 8 ≥ 9 ≥ 9.5
≥ 48 up to 60 ≥ 9 ≥ 9.5 ≥ 10.5 ≥ 11
≥ 60 up to 72 ≥ 10.5 ≥ 11 ≥ 12 ≥ 12.5
≥ 72 up to 84 ≥ 11.5 ≥ 12.5 ≥ 13 ≥ 13.5
≥ 84 up to 96 ≥ 12.5 ≥ 13.5 ≥ 14 ≥ 14.5
≥ 96 up to 180 ≥ 13 ≥ 14 ≥ 15 ≥ 15
≥ 180+ ≥ 13.5 ≥ 14.5 ≥ 15 ≥ 15