Transcutaneous Bilirubin Measurement in a Mixed Population: Clinical Evaluation of a New Device.
Harry K. Delchr, M.D. Chief Medical Officer
Greg Newman, Senior Optical Engineer
Shabbir Bambot, Ph.D., Senior Research Scientist
Steven L. Jaques,Ph.D., Oregon Medical Laser
Abstract : A heterogenous population of 165 newborn infants was studied between January 24, 1996 and May 31, 1996 at two hospitals.
Transcutaneous bilirubin (TcB)measurement and a heel stick sample were taken for determination of total serum bilirubin (TSB).
Regression analysis was performed on the TcB vs TSB and a high degree of correlation, r=0.938, was found between the two methods.
Other parts of the paper:
Most Studies of neonatal bilirubin spectral reflectance (transcutaneous) utilize 2-6 distinct wavelengths. The objective of this study is to determined if a new device,which records 221 individual wavelength band, can accurately estimate the TSB in newborns regardless os the skin pigmentation, skin maturity, or blood content.
The major skin components which impact the spectral reflectance in newborns are 1. collagen 2. melanin 3. hemoglobin and 4. bilirubin.
The total optical density at each measured wavelength is equal to the sum of the components, by utilizing known spectral characteristics of each component the contribution of the total Optical density can be sequentially subtracted until bilirubin is all that it is remaining.
Patient ethnicity: White 63%, African-American 19%, Hispanic 5%, Asian
11%, other 2%. Also there were of different weight, gestational age and days of like groups.
Results: ANOVA of patients characteristics :
Race p value 0.228 not significant
GA p value 0.066 not significant
Gender p value 0.879 not significant
Birth Type p value 0.953 not significant
Age 0.007 p value Significant
Interpretation: the not significant p values are the desired outcome for the first four variables, meaning they DO NOT interfere with the ability of the transcutaneous measuring device to predict accurately the total serum bilirubin. Age in the other hand IT IS expected to be significant because the older infant during the first few days of life will have increase levels.
TcB highly correlated with TSB, r = 0.938
Conclusion: The study device is able to accurately predict the serum bilirubin across a wide range of patients.
This is from one of the handout papers at New Orleans presentation of SPRX.
Does anybody knows how many wavelength bands are use by the CCSI instrument to determine bilirubin? Apparently SPRX is the first to use 221 individual wavelengths bands.
There is no mentioned of the ability of the SPRX device in the paper about the ability to measure accurately during phototherapy, this is one of the alleged disadvantages of the SPRX vs CCSI device according to some of the CCSI longs.
In my opinion, for both devices one will have to turn off the phototerapy lights during the short period of the measurement (few seconds). Phototherapy change bilirubin to a different isomer and this does not affect the measurement of total bilirubin, especially that the isomer is the identical mirror image of the indirect bilirubin. If anybody has any evidence to the contrary, please provide the explanation and it will be appreciated.
Sweet color the sugar one. |
