What should be measured in a newborn who presents with hyperbilirubinemia –: (A) Total & Direct bilirubin, (B) Total bilirubin only, (C) Direct bilirubin only, (D) Conjugated bilinibin only
Answer is A. Bilirubin is a tetrapyrrole and a breakdown product of heme catabolism.
Most bilirubin (70%-90%) is derived from hemoglobin degradation and, to a lesser extent, from other hemoproteins. In the serum, bilirubin is usually measured as both direct bilirubin (DBil) and total-value bilirubin
Direct bilirubin correlates with conjugated bilirubin but tends to overestimate actual conjugated bilirubin, as it includes both the conjugated bilirubin and bilirubin covalently bound to albumin (delta-bilirubin).
Indirect bilirubin correlates with unconjugated bilirubin but tends to underestimate unconjugated bilirubin, as a