Jaundice

• • Jaundice

• Conjugated bilirubin (direct) is easily excreted because it is soluble in water.

• Unconjugated bilirubin (indirect) is not soluble in water.
• Jaundice is clinically apparent when the serum total bilirubin is above 3 mg/dL (MCQ)
• • Hemolysis causes elevated indirect bilirubin. (MCQ)
  • Impaired conjugation is caused by
    • reduced hepatic uptake resulting from liver disease (eg, hepatitis) (MCQ)
    • conjugation enzyme deficiencies.
  • Conjugated hyperbilirubinemia is caused by
    • reduced hepatic excretion
    • impaired bile flow (eg, bile duct obstruction)
• Neonatal jaundice
• • • occurs during the first week of life.
    • There is a mild and transient rise in unconjugated bilirubin with a benign clinical course.
    • It is caused by inadequate production of glucuronyl transferase by the immature liver. (MCQ)
    • It is treated by UV exposure. (MCQ)
• Hemolytic disease of the newborn
• • • caused by maternal-fetal Rh incompatibility (MCQ)
    • more clinically ominous
    • usually has higher bilirubin levels than benign neonatal jaundice. (MCQ)
  • Breast milk jaundice
    • occurs in some breastfed newborns
    • usually after the first week(MCQ)
    • lasts longer than physiologic jaundice. (MCQ)
  • Gilbert syndrome
    • a common cause of slightly increased unconjugated bilirubin
    • it  is usually discovered by (MCQ)
• family history
• • • • an incidental finding in routine laboratory testing.
    • There is no hepatic impairment or clinical symptoms(MCQ)
    • If the patient becomes stressed, or febrile it may lead to jaundice.
  • Crigler-Najjar syndrome
    • is a severe familial glucoronyl transferase enzyme deficiency
    • very high unconjugated bilirubin levels.
• Type I
• • • • causes kernicterus
      • uniformly fatal.
• Type II
• • • less severe
    • responds to phenobarbital treatment(MCQ)
    • reduces the unconjugated bilirubin levels.
• Dubin-Johnson syndrome
  • an autosomal recessive disease (MCQ)
  • defective protein carrier in the bile canalicular membrane
  • leads to impaired bile excretion
  • black pigmentation of the liver (MCQ)
  • elevated conjugated bilirubin levels.