Exam 4 - Hyperbilirubinemia Flashcards
What is bilirubin?
End product of heme metabolism (breakdown of blood)
- Tends to deposit in the skin and mucus membranes (e.g. jaundice)
High versus low levels of bilirubin
High = toxic
- Neurologic changes (e.g. kernicterus)
Low = acts as antioxidant
What is the difference between conjugated and unconjugated bilirubin?
Conjugated = bound to glucuronic acid
- Water soluble
- More easily excreted by bile (easily eliminated)
Unconjugated = not bound
- Not water soluble so more difficult to excrete
What are the steps of bilirubin metabolism?
- Lysis or breakdown of RBCs
- Heme catalyzed by heme oxygenase
- Biliverdin converted to bilirubin
- Unbound bilirubin is transported to the liver to be bound to proteins (now water soluble)
- Excretion into bile
- Eliminated from the bowel through stool
What happens if bilirubin is left unbound in the body during bilirubin metabolism?
Will be reabsorbed into enterohepatic circulation –> increased jaundice and rising bilirubin levels
What is the peak level of jaundice in newborns? At what days does this occur?
Peak level is around 6 mg/dL between days 2 and 4 of life
What causes hyperbilirubinemia in newborns?
- Hepatic immaturity
- Decreased ability to conjugate bilirubin
- Decreased rate of excretion
- Mild dehydration/low caloric intake
What are the current guidelines for management of hyperbilirubinemia?
- Promote and support successful breastfeeding
- Increased intake for newborn = decreased risk for jaundice
- Establish nursery protocols for identification and evaluation (e.g. transcutaneous bilirubin checks)
- Measure total serum bilirubin (TSB) or total cutaneous bilirubin (TcB) levels of infants who are jaundiced in first 24 hours of life
Can transcutaneous bilirubin tools be used on premature infants?
No, only useful in full term infants
What tool can be used to interpret bilirubin levels according to the infant’s age in hours?
BiliTool - will give the breakdown of the infant’s risk
What two factors would put a newborn at increased risk for developing hyperbilirubinemia?
- Less than 38 weeks gestation
- Breastfed infants
Have more difficulty feeding/latching
Treatment options for hyperbilirubinemia
- Phototherapy
- Cover the newborn’s eyes
- Exchange transfusion
- Biliblankets
- Can be done at home and parents can still hold their babies
- Hydration
What are the major risk factors for hyperbilirubinemia?
- JAUNDICE acronym
- J - jaundice within first 24 hours
- A - sibling who was jaundiced as a neonate
- U - unrecognized hemolysis
- N - non-optimal sucking/nursing
- D - deficiency in G6PD
- I - infection
- C - cephalohematoma
- E - east asian or mediterranean descent
What is the difference between pathologic versus physiologic jaundice?
Pathologic…
- Occurs within the first 24 hours of life
- Isoimmunization
- Incompatibility between maternal and newborn blood or Rh(-) mom with Rh(+) baby–> increased hemolysis
- Erythrocyte biochemical defects (e.g. G6PD)
- Structural abnormalities (e.g. pyloric stenosis, duodenal obstruction)
- Infection
- Sequestered blood
How soon should families come in for primary care follow up after discharge?
For newborns discharged before 48 hours of life, first visit should be 1-3 days after discharge
Second visit will be 3-5 days after discharge
