Comparison of Newborn Serum Bilirubin Level with two Methods: Chemical and Direct Spectrophotometric

Objective: Bilirubin is the endproduct of heme catabolism. Serum bilirubin level can occationally be the only variable that affects the physician's decision. Bilirubin test is one of the most sensitive tests in the clinical laboratory. The aim of this research was to compare results of chemical versus direct spectrophotometric measurement of serum bilirubin.
Material & Methods: This cross-sectional study was carried out in 2006 on 119 specimens of serum. Bilirubin levels were determined by four methods: direct spectrophotometric by DAS and clinic II instruments, chemically with dichloroaniline (DCA), and diazo methods.
Findings: Mean serum bilirubin measured by DAS, clinicII, diazo, and DCA methods was 8.38 (3.59), 7.80 (3.69), 9.70 (4.06), and 8.17 (4.09) mg/dl respectively. Difference of means was significant when examined using ANOVA (P<0.001). The differences between diazo method and the other three methods were significant, while among the latter methods there was no statistically significant difference.
Conclusion: Regarding significant differences between methods, for a better orientation of the physician and more accurate follow up of patients, we recommend to mention the method of measurement in laboratory reports.

Keywords
Bilirubin , Chemical method , Direct spectrophotometric , Diazo , Newborn