<prompt> What should be measured in a newborn who presents with hyperbilirubinemiaTotal Direct bilirubinTotal bilirubin onlyDirect bilirubin onlyConjugated bilinibin only  <response>: 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 bilirubinDirect 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 