Efficacy of Transcutaneous Bilirubinometry as Compared to Serum Bilirubin in Preterm Newborn During Phototherapy

Transcutaneous measurement of bilirubin is being used for neonatal jaundice. Its utility during phototherapy in preterm babies is not established. Objective of our study was to assess the efficacy of transcutaneous bilirubin (TcB) measurement in comparison to total serum bilirubin in preterm newborns at admission and during phototherapy at covered skin area (glabella). It was a prospective observational study and conducted at neonatal intensive care unit of a tertiary care hospital from January 2017 to January 2019. One hundred eligible preterm neonates were enrolled. Babies who were very sick, with poor peripheral circulation, edematous, having conjugated hyperbilirubinemia, with major congenital malformations, already received phototherapy or exchange transfusion were excluded. Paired total serum bilirubin and transcutaneous bilirubin were measured at admission, at 6 hours and 24 hours during phototherapy. TcB was measured from area (glabella) covered by eye protector during phototherapy. Sample for TsB was taken within 10 minutes of TcB measurement. The mean difference between TsB and TcB values at admission, 6 hours and 24 hours of phototherapy were -0.005 (0.353), --0.350 (0.611), and -0.592 (0.353) respectively. At admission or before starting of phototherapy the difference (TsB-TcB) was statistically not significant (p=.125), while the difference in these values were statistically significant at 6 hours and 24 hours of phototherapy. Conclusion: TcB measurements from covered skin area in jaundiced preterm infants during phototherapy were not correlated with TsB and cannot be used as an alternate of serum bilirubin levels.