Estimation of bilirubin using BiliChek™, a transcutaneous bilirubin measurement device: Effects of gestational age and use of phototherapy

Abstract

BACKGROUND: Heel puncture to obtain bilirubin measurements is painful for infants and distressing for parents. Transcutaneous bilirubin measurement using BiliChek (Respironics, USA) is easily performed in any setting. Reliable transcutaneous testing should decrease the number of painful procedures in otherwise well infants, reduce the volume of phlebotomy losses in ill newborns, and reduce the need for hospital or specialized clinic visits after discharge. OBJECTIVE: To correlate bilirubin measurements using the transcutaneous device BiliChek with 'gold standard' serum measurements in well term infants, and in ill term and preterm infants admitted to the authors' neonatal intensive care unit. METHODS: The study consisted of two phases. In phase 1, informed consent was obtained from mothers of 99 healthy, full-term infants not receiving phototherapy to perform both serum and transcutaneous bilirubin measurements at the time of heel puncture for routine neonatal screening. In phase 2, 56 infants in the neonatal intensive care unit had a total of 99 transcutaneous readings performed at the time serum bilirubin measurements were ordered for clinical reasons by the attending staff. The operators of the transcutaneous device, who were unaware of the serurn bilirubin levels, performed readings within 1 h of the heel puncture. RESULTS: Using a Bland-Altman comparison in the well term infants, the transcutaneous measurements were -32.2 μmol/L to +31.2 μmol/L (1.96 SD); however, 79 (79.8%) of the transcutaneous measurements were within 15 μmol/L of the serum measurements. The variation in preterm infants was greater at -69.6 μmol/L to +62.0 μmol/L, and only 49 (49.5%) were within 15 μmol/L. For infants receiving phototherapy, the variation was -76.3 μmol/L to +49.5 μmol/L, but improved to -40.4 μmol/L to +31.0 μmol/L if an area of skin was patched for testing, approximating the group not receiving phototherapy. CONCLUSIONS: Transcutaneous bilirubin measurements obtained with the BiliChek instrument were accurate for measuring bilirubin levels in term jaundiced infants not receiving phototherapy and in those receiving phototherapy if an area of skin was patched. The instrument was not as sensitive in the small sample of preterm infants, and a larger study is required before recommending the use of this instrument in this population. © 2006 Pulsus Group Inc. All rights reserved.