Conjugated bilirubin: a better indicator of impaired hepatobiliary excretion than direct bilirubin.

A prototype KODAK EKTACHEM Clinical Chemistry Slide (BuBc) provided a measurement of serum conjugated bilirubin which was at least as sensitive to developing conjugated hyperbilirubinemia as values provided by a direct (diazo) bilirubin assay. Under conditions where the impairment of hepatobiliary excretion was relieved in patients being treated for various hepatobiliary diseases, conjugated bilirubin was cleared from serum more rapidly than alkaline phosphatase, the delta bilirubin fraction, and bilirubin measured by the direct and total bilirubin assays. It is concluded that the conjugated bilirubin measurement provided by the BuBc Slide appears to be an earlier indicator of relief from hepatobiliary cholestasis, or conversely of residual impairment, than direct bilirubin, total bilirubin, or alkaline phosphatase.