Hyperbilirubinemia is a common problem in the newborn infant. It can progress to develop kernicterus unless intervention is initiated. Severity and decision for management are usually based on serum bilirubin (TsB) which needs blood sampling. Transcutaneous bilirubin measurement is a noninvasive technique and the result correlates closely with TsB. A new transcutaneous bilirubinometer, Minolta AirShields Jaundice Meter, JM103, has been introduced. The objectives of this study were: 1) To evaluate the accuracy of transcutaneous bilirubin (TcB) measured by JM 103, when compared to TsB, used clinically in a hospital setting (Leica Unistat Bilirubinometer) and 2) To develop a cut-off point of TcB level which indicated the need for serum bilirubin assessment.
Three hundred and eighty eight term and near-term newborn infants with 460 paired TcB-TsB specimens were studied from August to November 2003. Birth weight was 3117.57 + 424.82 grams. TsB ranged from 4 to 19.6 mg/dL(x 10.5, SD 2.46). The correlation coefficient between TcB and TsB was significant (r 0.8, p < 0.001). TcB showed a tendency to underestimate TsB, with mean difference of 0.7 mg/dL, SD 1.6 mg/dL, and 95% confidence interval 0.85 and 0.55 mg/dL. TcB values of 8, 9, 10, 12 mg/dL were chosen as cut-off points that indicated the need for blood sampling for TsB (corresponded to hour-specific levels of 10, 12, 13 and 15 mg/dL, respectively when phototherapy should be initiated). In conclusion, noninvasive TcB assessment demonstrates significant accuracy, compared to TsB. It can be used as a screening test to identify the need for blood sampling for serum bilirubin level.
Keyword : Transcutaneous bilirubin, Hyperbilirubinemia, Jaundice, Newborn infants