jaundice

Question 1

what percent of term and preterm newborns develop jaundice

Answer 1

60% of term

80% of preterm

Question 2

what qualifies as severe hyperbilirubinemia in a neonate? critical?

Answer 2

TSB of greater than 340–severe

TSB greater than 425–critical

Question 3

why do we worry about critical hyperbilirubinemia?

Answer 3

acute bilirubin encephalopathy

increased risk if TSB 428-513

however, variable susceptibility depending on hydration status, respiratory rate, prematurity, acidosis etc

Question 4

what is the clinical syndrome of acute bilirubin encephalopathy

Answer 4

severe hyperbilirubinemia
lethargy
hypotonia
poor suck

may have hypertonia (opisthotonos and retrocollis), high pitched cry and fever, or seizures and coma

Question 5

what is kernicterus?

Answer 5

deep yellow staining of neurons and neuronal necrosis within basal ganglia and brainstem nuclei

Question 6

what is chronic bilirubin encephalopathy

Answer 6

clinical sequelae of acute bilirubin encephalopathy

athetoid cerebral palsy with or without seizures, developmental delay, hearing deficit, oculomotor disturbances, dental dysplasia

Question 7

when should newborns have their bilirubin tested?

Answer 7

between 24 and 72 hours of life

to pair with metabolic screening test if possible

test earlier if visibly jaundiced or risk factors present

Question 8

is all jaundice pathological?

Answer 8

no

Question 9

what is physiological jaundice –when does it happen and what causes it

Answer 9

day 2-3 of life

caused by–

1. decreased life span of RBCs
2. neonates are relatively polycythemic
3. immaturity of liver enzymes to conjugate bilirubin

rate of rise is LESS THAN 3mmol/hour

exacerbated by weight loss and dehydration (breastfeeding jaundice)

Question 10

what is breastmilk jaundice

Answer 10

develops at 4-7 days of life

persists longer than physiologic jaundice

breastmilk contains inhibitors of hepatic glucoronyl transferase (UDPGA)

usually levels are insufficiently high for ABE

Question 11

what are the risk factors for pathological jaundice

Answer 11

1. hemolysis
   - -Rh/ABO incompatibility
   - -G6PD deficiency
   - -sepsis, acidosis, respiratory distress, temperature instability
2. impaired enterohepatic circulation
   - -lethargy with poor intake

Question 12

what is HDFN and what does it cause

Answer 12

blood type incompatibility between mother and infant (i.e type O, Rh negative mom)

IgG antibodies cross placenta–> can happen in first pregnancy for ABO incompatibility, usually second pregnancy for Rh (sensitized in first exposure)

causes hemolysis, therefore…

symptomatic anemia–> supportive care

hyperbilirubinemia

Question 13

what is G6PD deficiency

Answer 13

lack of enzyme renders mature RBC unable to handle oxidative stress
–i.e delivery and associated physiologic changes, or sepsis, meds or other triggers

x linked inheritance

can cause hemolysis…
symptomatic anemia–> supportive care
hyperbilirubinemia

Question 14

what tool do we use to decide management of hyperbilirubinemia in the neonate

Answer 14

bhutani nomogram

Question 15

how does the bhutani nomogram work

Answer 15

risk stratifies by age and TSB

high risk–> 40% require intervention

high intermediate–> 13% require intervention

low intermediate–> 2%

low–> 0%

Question 16

what do you do for those kids who score high or high intermediate on the bhutani nomogram

Answer 16

repeat TSB in 24 hours or at 4-8 hours to see rate of rise

Question 17

what do you do for those kids who score low intermediate or low on the bhutani nomogram

Answer 17

no repeat TSB, follow up in 3-4 days

Question 18

how do you treat hyperbilirubinemia

Answer 18

phototherapy

use light (460-490 nm) to convert bilirubin (lipophilic) into water soluble isomers (Z-lumirubin)

this bypasses glucoronidation

can then be excreted into bile and urine

Question 19

what are the contraindications to phototherapy

Answer 19

concomitant use of photosensitizing meds

congenital erythropoeitic porphyria

Question 20

what must you do to prevent complications from phototherapy

Answer 20

eye protection

monitor temp

monitor hydration (BF, EBM with or without IVF)

avoid photosensitizing meds like quinolones or diuretics