1455 TRANSCUTANEOUS BILIRUBINOMETRY IN BLACK & HISPANIC INFANTS

Abstract

In an effort to reduce the number of blood sampling, trauma, blood loss due to invasive procedures for serum bilirubin determination, Yamanouchi & Minolta Co. developed a transcutaneous device for measuring subcutaneous bilirubin. This small hand held, spectrophotometric, fiberoptic zenon lightmeasures in 1 second the color intensity of the skin & subcutaneous tissue. It gives a numerical index which was shown to correlate well with the total serum bilirubin concentration of Japanese (Yamanouchi) & with white infants (Lucey). We used the same methodology in black & Hispanic term infants to see if skin color will affect the correlation. None received phototherapy. A total of 112 measurements were done on 71 black term infants (Wt. 2510-4000 gm, age 11-207 hrs, Bil. 1.6-17.7mg%) at 4 different sites. The correlation was best at mid-sternum with correlation coefficient r=0.80 p 0.001 & the standard error of estimate 1.83. In 24 Hispanic infants (69 measurements, Wt. 2530-3970 gm, age 20-132 hrs, Bil. 4.6-15.6 mg%), the best site of correlation was mid-sternum with r=0.64, p 0.001 & standard error of estimate 1.84. The correlation was good in black infants but not as good as in Japanese infants (r= 0.93). This suggests that dark skin made some difference. The correlation was less than adequate in Hispanic infants, (r=0.64) probably because their skin color varies. Considering the cost of conventional serum bilirubin determination (av. $54/test) Tc Bilirubinometry is not only cost effective but also painless & time saving.