Clinical Chemistry, Vol 33, 1662-1664, Copyright © 1987 by American Association for Clinical Chemistry

Clinical utility of Ektachem-determined bilirubin fractions for classifying adult inpatients

GA Tetrault, BA Meiklejohn and CE Sparks

We determined total bilirubin, "direct" and "indirect" bilirubin fractions, and, in parallel, using Ektachem slides, the total, conjugated, unconjugated, and delta bilirubin contents for specimens from 88 adult inpatients at various times during hospitalization in a tertiary-care facility. We wanted to see if the results correlated with the patients' diagnoses, based on a review of medical records and other laboratory data. The patients (including some with mixed disease types) were assigned to one of three predominant disease-process groups: obstructive liver disease, parenchymal liver disease, or hemolytic disease. Ektachem bilirubin fractions and the comparable total, "direct," and "indirect" bilirubin fractions showed equal sensitivity in screening and monitoring disease in all three groups. Measurements of conjugated bilirubin, unconjugated bilirubin, and their sum were sufficient for evaluating bilirubin abnormalities in this complex patient population. Determining delta bilirubin with the total bilirubin slide was rarely useful clinically. Thus, laboratories using Ektachem instrumentation for bilirubin testing can routinely eliminate the extra costs and occasional problems associated with running both bilirubin slides, reserving delta bilirubin determinations for unusual cases.