Flashcards in Pediatric Jaundice - Newman Deck (37)
what is heme broken down into?
biliverdin and CO
what is biliverdin reduced to?
how do you get free unconjugated bilirubin?
albumin-binding sites are saturated, or unconjugated bilirubin is displaced from albumin by medicine
is unconjugated bilirubin lipid soluble?
yes, so it can cross the BBB
high hematocrit and RBC volume
- RBC with shorter life span
- inadequate conjugation of bilirubin by the liver due to immaturity of hepatic glucuronosyltransferase
- lots of unconjugated bilirubin present in their blood!
what is the most common type of bilirubin involved in neonatal hyperbilirubinemia
- a result of hemolysis of RBC's
levels of what, increase rapidly in the first few weeks after birth?
- initially the level is very low, overwhelming the amount of unconjugated bilirubin presented in the liver
what enzyme is located in the intestine, and deconjugates bilirubin (making it water soluble), allowing it to be reabsorbed from the gut into the blood?
- the rest is excreted in the stool
visible jaundice early in life usually means that the transcutaneous serum bilirubin (TSB) is at what level?
what causes jaundice?
caused by dehydration and decreased excretion of bilirubin in the stool (more supply related)
breast FEEDING jaundice
due to the presence of bilirubin deconjugating enzymes in milk
breast MILK jaundice
conjugated hyperbilirubinemia is always what?
what causes unconjugated hyperbilirubinemia?
- increased bilirubin production: erythrocyte-enzyme def, ABO incompatibility, RBC structural defects, *G6PH def*
- hepatic uptake def
- impaired conjugated: Gilbert synd, Crigler-Najjar type 1, severe UGT1A1 def
all moms that are type O blood, or Rh (D) neg must have what test done?
a direct coombs test
- tests for autoimmune hemolytic anemia (erythroblastosus fetalis)
also check the infant's cord blood
what causes conjugated hyperbilirubinemia?
- UTI or sepsis
- **biliary atresia/cholestasis*
first 1-2 days of life
- poor suck
- high pitched cry
phase 1 of acute bilirubin toxicity
middle of first week of life
- hypertonia of extensor muscles
phase 2 of acute bilirubin toxicity
after the first week of life
phase 3 of acute bilirubin toxicity
first year of life
- active DTR's
- obligatory tonic-neck reflexes
- delayed motor skills
phase 1 of BIND (bilirubin induced neurologic dysfunction)
KNOW this phase!
- choreoathetotic cerebral palsy
- ballismus (spontaneous movements)
- upward gaze
- dental dysplasia
- sensorineuronal hearing loss
- cognitive impairment
phase 2 of BIND
what do you assess for icterus?
the sclera and mucous membranes
- jaundice in the first 24
- ABO incompatibility with positive DAT
- hemolytic disease (G6PD, hereditary spherocytosis)
- gestational age 35-36 weeks (preterm)
- previous sibling requiring phototherapy
- cephalohematoma or bruising (from vaccuum delivery)
- exclusive breatfeeding (esp if it's not going well)
- east Asian race
risk factors for severe hyperbilirubinemia
what are the 3 biggest risk factors for hyperbilirubinemia?
- high hematocrit at birth
- ABO incompatibility
what is the measurement for excessive jaundice in infants?
jaundice to neck = 5
jaundice to waist = 10
jaundice to toes = 15
what tests need to be run when TSB increases rapidly or baby is unexpectedly jaundiced upon initial exam?
- BT and DAT (coombs)
- CBC and peripheral smear
- conjugated bili level
- reticulocyte count
- repeat TSB in 4-24 hours
what labs should be run when conjugated bilirubin is elevated?
- blood cultures
- consider intra-hepatic or post-hepatic abnormalities
what labs should be run when baby has prolonged jaundice (greater than 3 weeks)?
- TSB, always order fractionated! (need unconj and conjugated)
- check newborn screens (hypothyroid, galactosemia)
if baby has jaundice for 2 months, what disease should you consider?