We read with interest the recent article on this subject(1). As stated
by the authors most of the presently available methods of bilirubin
estimation in neonates are associated with problems of poor correlation
with serum bilirubin, requirement for sophisticated equip-ment, high
cost and macro blood samples from the tiny babies. The authors objective
of developing a simple, reliable and reproducible method is well appreciated.
The present study however does not seem to obviate the need for any
of the above requirements:
1.
Since the authors did not check the stability of the color in the
dilutions, the procedure is going to be tedious, as the dilutions
need to be made daily. The procedure will also require about 20 test
tubes, which need to be changed frequently to maintain the transparency.
2.
Since bilirubin estimation by plasma color index is subjective, the
reported correlation between serum bilirubin and color index needs
to be substantiated by the 95% confidence limits for each of the color
indices. Interobserver and interlaboratory measurements of bilirubin
may differ up to 30%(2). Blinding, inter and intraobserver measurements
can strengthen the study.
3.
Though the sample collected is only in micro liters, the procedure
does require costly equipment such as the micro centrifuge and also
the capillary tubes (Rs. 120 to Rs 150 per 100 pieces).
It
was distrurbing to read that the authors have collected blood samples
for bilirubin estimation from femoral puncture. This proce-dure is known
to be associated with serious complications(3) and hence it was unethical
and unjustifiable to have done so. The addi-tional heel prick given
to the babies could have been avoided had the capillary samples been
obtained from the blood samples collected.
From
the discussion it is clear that this study has methodological fallacies
and also doesn’t meet the authors objective of develop-ing a simple,
reliable, cheap and minimally invasive technqiue for accurate bilirubin
estimation.
As
of now the bilirubin estimation by filter paper technique using jaundice
meter(4) appears to be the most simple, minimally invasive and accurate
method of bilirubin estimation in newborns.
