Neonatal bilirubin triage with transcutaneous meters: when is a blood draw necessary?

Abstract

Objective: To find the optimal transcutaneous bilirubin (TcB) screening level in term neonates that minimizes the discomfort of phlebotomy, while protecting the child from harm and controlling costs.

Methods: All available TcB and total serum bilirubin (TSB) measurements taken between 27 and 51 hours of life from a cohort of term newborns were analyzed in a retrospective chart review. TcB cutoffs between 6 and 12 mg/dL were evaluated for their negative predictive values (NPVs) for high risk (HR) and for the combination of high-intermediate risk and HR on the Bhutani TSB risk nomogram.

Results: One thousand seventy-one full-term newborns were entered into the study. Of 601 newborns with TcB < 7 mg/dL, none were HR by TSB. Of newborns with a TcB of < 8 mg/dL, 1 in 759 was HR. The NPVs for screening levels of 7 and 8 mg/dL were of 100% and 99.9%, respectively, for HR and 99% and 97.60%, respectively, for high-intermediate/HR. A cutoff at 12 mg/dL had NPVs of 99.3% for HR, with 7 neonates, and 92.7% for high-intermediate/HR, with 76 infants of 1041.

Conclusions: In our center, term infants with a TcB of < 8 mg/dL may be safely discharged without a follow-up TSB, with the understanding that -1/1000 infants may be at HR for developing severe hyperbilirubinemia. Practices with universal follow-up may safely choose cutoffs up to 12 mg/dL. An institution's degree of comfort and confidence in follow-up of the newborn cohort will guide the choice of an appropriate TcB cutoff requiring a TSB.