Neonatal Jaundice Flashcards
Why is breastfeeding a risk factor for neonatal jaundice?
- breast milk fatty acids inhibit albumin transport of the bilirubin
- fatty acids of breast milk interfere with the UDP glucuronyl transferase so unconjugated bilirubin will build up in the serum
- breastmilk doesn’t usually come in until day 3-4 and feeding is what allows gut colonization. Without the intestinal flora, the conjugated bilirubin in the bile is resorbed, leading to a increase in the total serum bilirubin
what is the difference between dehydration-breastfeeding- associated jaundice and breast milk jaundice?
Dehydration- breast-feeding associated jaundice► Breast milk production is usually very low in the first 3 days of life, infants will develop some minor/ not so minor, dehydration, leading to poor excretion of the conjugated bilirubin
Breast milk jaundice► the presence of the FAs in the milk inhibits bilirubin transport by albumin as well as conjugation (and thus excretion) of bilirubin
Why do all infants have some degree of physiologic jaundice?
Why is this more pronounced (often requiring treatment) in premature infants?
All newborns develop physiologic jaundice to some degree. (rarely above 13mg/dl of bilirubin)→ mild skin jaundice and scleral icterus, and causes no problems
Cause: born with a high RBC count, to compensate for their somewhat hypoxic state in utero→→ RBCs begin to breakdown fairly soon after birth so there is naturally a increased amount of bilirubin being produced.
premature infants have less serum albumin (high bilirubin/albumin (B/A) ratios increase the risk of bilirubin neurotoxicity)
list some causes of jaundice (separated into increased RBC breakdown vs decreased bilirubin clearance)
Which lab test can tell you if a baby’s RBCs are marked for destruction (ie there is an ABO or Rh incompatibility)?
A Coombs test
MC is ABO incompatibility (mother is O+ and the baby is not)
The direct Coombs test is used to detect antibodies that are stuck to the surface of RBCs. Many diseases and drugs can cause this. These antibodies sometimes destroy red blood cells and cause anemia.
What are two serious consequnces of untreated hyperbilrubinemia that leads to kernicterus?
Kernicterus=deposition of bilirubin in the brain
- leads to serious neurologic injury
- permanent hearing loss
Why do we ask about “ins and outs” while taking a history on a jaundiced infant?
intake: formula or breastfed, how much taking in (tells us about potential for breastmilk or breastfeeding-assoc jaundice), tells us if latch is good
Urine out put, stooling including color: use to determine hydration status (neonates usually urinate every 2 hours after the first dol, and stool with every feeding. The color of the stool helps to ascertain the presence of bile and transitions from the black tar of meconium to the dark green of transitional stool, to the yellow of bile-containing stool.
How often should young infants be feeding?
Young neonates need to be awakened to feed every 2 hours
Sometimes parents are not aware that they need to wake thier child up to feed and the child may become dehydrated.
Ask mom if she feels a sense of breast engorgement before feeding followed by a sensation of emptying during feeding to assess for a good latch.
Factors which contribute to pathologic jaundice:
- Ethnicity (Asian, Mediterranean, African ancestry)
- O+ maternal blood type
- maternal infections or post-natal infant infections
- any FHx of RBC abnormalities
- metabolic disorders
- significant neonatal jaundice in siblings
What is “normal” weight loss after birth and what is concerning?
How is weight loss calculated?
weight loss %: birth weight- current weight (make sure it is naked), divided by the birth weight
eg born 7lbs, weighs 6.8 at day 2
(7-6.8)/7= 2.9% weight loss
►acceptable for newborns to lose 2-3% of their birth weight per day through day 3, should begin gaining as mom’s milk comes in
►weight should be regained within 2 weeks of life
** Formula fed infants rarely lose any weight
How do we assess neurological status of an infant?
What would an abnormal neuro exam in a jaundiced infant tell us?
assess their response to stimuli such as being cold, bright lights, or their extremities being pulled on
tells us whether the child has kernicterus, not the cause of his jaundice
What info do you need to use the calculator at Bilitool.org?
What do the results tell us?
total bilirubin level of the infant,
birth time
time of blood draw
(or use the infant’s age in hours with total bili)
→Helps determine the child’s risk for severe hyperbilirubinemia, as well as provides guidance for when to start phototherapy or exchange transfusion and when to follow up the bilirubin level.
The AAP phototherapy guidelines require the provider to also assess risk to determine Tx (2nd eval after bililevel puts into initial level based on nomogram)
Low risk is a full-term infant who appears well.
What risk factors place the infant in a higher risk group?
prematurity,
showing signs of neurotoxicity,
pathologic cause of the jaundice
(the threshold for phototherapy would be lower)
In what pattern does hyperbilrubinemia develop (anatomically)?
Bilirubin deposits in keratinized tissue,
skin of the face→descends caudally→sclera
It resolves in the reverse direction.
Determine how far down the body it has developed as a guide for how high the serum bilirubin levels are: abdomen and thighs being a threshold for getting serum bilirubin levels.
You have already tested transcutaneous bilirubin in your office, which was abnormal, so you also got a total serum bilirubin test, which confirmed abnormally high total bili.
If you found any concerning Hx or PE findings or if were seeing rapidly rising bilirubin levels, what additional testing is needed?
CBC with peripheral smear
Reticulocyte count
Fractionated serum bilirubin (Total, direct, indirect)
Coombs test, direct and indirect (ABO incompatilibilty?)
Not usually done initially- tests for infection (urine,TORCH titer)
What are options for treating jaundice?
Use the bilitool to help you with treatment decision-making.
Tx options:
- discharging to home with q 24hr serum bilirubin rechecks
- home bilirubin blanket or light phototherapy with q 24hr rechecks
- inpatient care (tend to use inpatient care for those where pathologic jaundice or neurologic toxicity is a concern, or if follow-up is an issue)
Which class of antibiotics, if given during the final weeks of pregnancy can cause jaundice in the newborn?
sulfa drugs
(competitive binder at albumin)
Often the newborn screen is not back when infants are evaluated, so the index of suspicion for a metabolic defect needs to remain high if find high direct bilirubin levels.
Who do you need to call in this situation?
Call state dept of health to expedite newborn screen results.
In particular: Cystic fibrosis causes slow gut motility resulting in decreased bile clearance
Newborn screen also includes tests for inborn errors of metabolism, other genetic disorders, hemoglobinopathies
What is the time frame for correcting biliary atresia in order to avoid a liver transplant?
by the second month of life in order to avoid liver failure necessitating a liver transplant
