Interpretation of Plasma on Studies With
- Joseph R. Bloomer, MD;
- Paul D. Berk, MD;
- Robert B. Howe, MD;
- Nathaniel I. Berlin, MD
Abstract
The plasma unconjugated bilirubin concentration (Br) is related to the bilirubin production rate (BRP) and hepatic bilirubin clearance (CBr) in the following manner: Br = BRP ÷ CBr. The distribution for Br in the normal population was calculated from this relationship, using normal values of BRP and CBr measured with labeled bilirubin. The results indicate that any individual with a Br exceeding 1.0 mg/100 ml (99% level) should be suspected of having abnormal hepatic function or bilirubin overproduction or both. A Br greater than 3.5 mg/100 ml usually indicates abnormal hepatic function, regardless of the BRP. A change in Br means that either bilirubin production or hepatic function has been altered, even if Br remains within the normal range.
Footnotes
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Reprint requests to 4N117 Bldg 10, National Institutes of Health, Bethesda, Md 20014 (Dr. Bloomer).
