Accuracy of enhanced transcutaneous bilirubinometry according to various measurement sites

Abstract

Objective: The goal of the study was to provide missing data on the accuracy of enhanced transcutaneous bilirubinometry in a monoracial population of term neonates, considering three different measurement sites.

Material and methods: Transcutaneous bilirubin was measured using the JM-105 device on the forehead, chest, and abdomen. Blood sampling for total serum bilirubin concentration has been performed within 10 minutes of transcutaneous measurements. Paired transcutaneous bilirubin and total serum bilirubin measurements were statistically analyzed.

Results: The study group consisted of 102 healthy term Slovak infants. The correlation between total serum bilirubin and transcutaneous bilirubin was significant (coefficient of determination R2: 0.9045 forehead, 0.8808 sternum, 0.8467 abdomen). Transcutaneous measurements underestimated serum bilirubin levels significantly when total serum bilirubin values were higher than 15 mg/dL, irrespective of the site of transcutaneous measurements. The lowest mean difference between total serum bilirubin and transcutaneous bilirubin was identified on the sternum (median: -1.1 mg/dL). The area under the curve was >0.97 and >0.93 for detecting total serum bilirubin levels >10 mg/dL and >13 mg/dL, respectively, for all measurement sites. Transcutaneous measurements on the forehead and sternum provided very high sensitivity, with the best performance at the forehead.

Conclusion: Transcutaneous bilirubinometry using an enhanced device is an accurate, sensitive, and convenient screening method in term Caucasian neonates. Transcutaneous bilirubin measurements on the forehead, sternum, and abdomen are reliable, with the best performance on the forehead. It is necessary to confirm higher transcutaneous bilirubin values with a total serum bilirubin measurement.

Keywords: Bilirubin; hyperbilirubinemia; jaundice; neonates; transcutaneous bilirubinometry.

Figure 1

The Bland-Altman plots for the study group (n=102) at the three measurement sites (forehead, sternum, abdomen). The lines represent mean differences between TSB and TcB for each site and ±1.96 × SD of the difference SD, standard deviation; TcB, transcutaneous bilirubin; TSB, total serum bilirubin

Figure 2

Linear regression plots of TSB versus JM-105 TcB measurements obtained from different body sites (forehead, sternum, abdomen) of the study group (n=102). p<0.0001 for each measurement site TcB, transcutaneous bilirubin; TSB, total serum bilirubin

Figure 3

Receiver operating characteristics curve analyses of TcB values for detecting TSB levels of >10 mg/dL, >13 mg/dL, and >15 mg/dL, at the three body sites (forehead, sternum, abdomen) TcB, transcutaneous bilirubin; TSB, total serum bilirubin