Abstract 1089 Poster Session IV, Tuesday, 5/4 (poster 353)

Background: TSB can be measured by transcutaneous technique in a newborn infant. Using spectral reflectance analysis, the value is determined by the maturation of the skin, the rate of subcutaneous deposition of bilirubin, and the interfering spectral effects of skin based pigments hemoglobin, melanin, and chromophores. The BiliCheck™ is a transcutaneous bilirubin measurement device that uses spectral reflectance analysis algorithms based on recent studies of the dermal light scattering and light absorption characteristics of neonatal skin and corrects for the interfering pigments. The hand-held device displays a single point-in-time bilirubin value. Objective: To determine the clinical accuracy and precision of TcB measurements by comparison with TSB (measured by HPLC technique) using linear regression analysis. Multiple hand-held devices were compared in a neonatal population with diverse birth weights (BW), gestational ages (GA), and ethnicities. Methods: Blood samples were obtained by heel stick, for later TSB analysis by HPLC, simultaneously with TcB measurements. Multiple TcB measurements were taken from the forehead of each newborn with 2-4 different devices. A TcB value was displayed at the time of the measurement and data were stored on a laptop computer for additional analysis. Results: Eleven devices were used to obtain 1970 TcB values in a sample population of 508 newborns at 2 geographic sites (PaH, NH). BW range was 1535-5665g, GA: 32-42 weeks. The ethnic breakdown was 65.5% Caucasian, 27.5% African-American and 7.0% other. The TSB values ranged from 0.5-20.0 mg/dl. Linear regression result between TcB and TSB was r = 0.909 (y=0.983x + 0.55), RMSE=1.44, SE y=1.38 mg/dl, p<0.0001. Device precision was: intra-device SD=0.59 mg/dl (n=210, 2-3 measurements/patient) and inter-device SD=0.68 mg/dl (n=569, 2-4 measurements/patient). Conclusion: These data demonstrate the accuracy and reproducibility of TcB measurements in all patients studied using this method of spectral reflectance analysis. Further studies are recommended to attain intra-device precision for this and any other non-invasive techniques and for their use in very low birth weight infants and those newborns exposed to phototherapy.

(Supported in part by SpectRx, Inc. Norcross, GA).