Pediatric Jaundice - Newman

Question 1

what is heme broken down into?

Answer 1

biliverdin and CO

Question 2

what is biliverdin reduced to?

Answer 2

bilirubin

Question 3

how do you get free unconjugated bilirubin?

Answer 3

albumin-binding sites are saturated, or unconjugated bilirubin is displaced from albumin by medicine

Question 4

is unconjugated bilirubin lipid soluble?

Answer 4

yes, so it can cross the BBB

Question 5

high hematocrit and RBC volume

• RBC with shorter life span
• inadequate conjugation of bilirubin by the liver due to immaturity of hepatic glucuronosyltransferase

Answer 5

newborns

- lots of unconjugated bilirubin present in their blood!

Question 6

what is the most common type of bilirubin involved in neonatal hyperbilirubinemia

Answer 6

UNconjugated

- a result of hemolysis of RBC’s

Question 7

levels of what, increase rapidly in the first few weeks after birth?

Answer 7

UGT1A1

- initially the level is very low, overwhelming the amount of unconjugated bilirubin presented in the liver

Question 8

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?

Answer 8

beta-glucuronidase

- the rest is excreted in the stool

Question 9

visible jaundice early in life usually means that the transcutaneous serum bilirubin (TSB) is at what level?

Answer 9

5 mg/dL

Question 10

what causes jaundice?

Answer 10

hyperbilirubinemia

Question 11

caused by dehydration and decreased excretion of bilirubin in the stool (more supply related)

Answer 11

breast FEEDING jaundice

Question 12

due to the presence of bilirubin deconjugating enzymes in milk

Answer 12

breast MILK jaundice

Question 13

conjugated hyperbilirubinemia is always what?

Answer 13

pathologic!

Question 14

what causes unconjugated hyperbilirubinemia?

Answer 14

• 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

Question 15

all moms that are type O blood, or Rh (D) neg must have what test done?

Answer 15

a direct coombs test
- tests for autoimmune hemolytic anemia (erythroblastosus fetalis)

also check the infant’s cord blood

Question 16

what causes conjugated hyperbilirubinemia?

Answer 16

• UTI or sepsis
• **biliary atresia/cholestasis*
• hypothyroidism
• galactosemia

Question 17

first 1-2 days of life

• poor suck
• high pitched cry
• stupor
• hypotonia
• seizures

Answer 17

phase 1 of acute bilirubin toxicity

Question 18

middle of first week of life

• hypertonia of extensor muscles
• retrocollis
• fever

Answer 18

phase 2 of acute bilirubin toxicity

Question 19

after the first week of life

- hypertonia

Answer 19

phase 3 of acute bilirubin toxicity

Question 20

first year of life

• active DTR’s
• obligatory tonic-neck reflexes
• delayed motor skills

Answer 20

phase 1 of BIND (bilirubin induced neurologic dysfunction)

KNOW this phase!

Question 21

• choreoathetotic cerebral palsy
• ballismus (spontaneous movements)
• tremor
• upward gaze
• dental dysplasia
• sensorineuronal hearing loss
• cognitive impairment

Answer 21

phase 2 of BIND

Question 22

what do you assess for icterus?

Answer 22

the sclera and mucous membranes

Question 23

• 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

Answer 23

risk factors for severe hyperbilirubinemia

Question 24

what are the 3 biggest risk factors for hyperbilirubinemia?

Answer 24

• prematurity
• high hematocrit at birth
• ABO incompatibility

Question 25

what is the measurement for excessive jaundice in infants?

Answer 25

jaundice to neck = 5 jaundice to waist = 10 jaundice to toes = 15

Question 26

what tests need to be run when TSB increases rapidly or baby is unexpectedly jaundiced upon initial exam?

Answer 26

- BT and DAT (coombs) - CBC and peripheral smear - conjugated bili level - reticulocyte count - repeat TSB in 4-24 hours

Question 27

what labs should be run when conjugated bilirubin is elevated?

Answer 27

- UA - blood cultures - consider intra-hepatic or post-hepatic abnormalities

Question 28

what labs should be run when baby has prolonged jaundice (greater than 3 weeks)?

Answer 28

- TSB, always order fractionated! (need unconj and conjugated) - check newborn screens (hypothyroid, galactosemia)

Question 29

if baby has jaundice for 2 months, what disease should you consider?

Answer 29

Gilberts

Question 30

- most DC babies at 48 hours of life - bilirubin greater than 24 hours of life - DAT in babies born to Type O and Rh neg moms - folluw up of the newborn within 2 days of DC

Answer 30

hospital protocol

Question 31

- increase frequency of feedings - continue breast feeding if inadequate oral intake, excessive weight loss (>12% of birth weight), or dehydration, the baby should receive supplemental breast milk/formula

Answer 31

tx for mild jaundice, not a candidate for phototherapy NOTE: exchange transfusion is considered when bili is >25 mg/dL or when symptoms of acute encephalopathy are present

Question 32

what makes bilirubin water soluble?

Answer 32

isomerization (H-bonds to water, rather than internally H-bonded)

Question 33

progressive nad destructive inflammatory process affecting both the extra and intrahepatic biliary tree - development of jaundice in the first few post-natal weeks - **cholestatic jaundice, hepatomegaly, acholic stools**

Answer 33

conjugated hyperbilirubinemia

Question 34

- "giant cell" hepatitis - prolonged cholestatic jaundice - liver biopsy shows a very disrupted hepatic architecture

Answer 34

idiopathic neonatal hepatitis

Question 35

syndromic bile duct paucity or arteriohepatic dysplasia - AD - marked reduction of intrahepatic bile ducts

Answer 35

Alagile syndrome

Question 36

- liver disease resulting from retention of abnormal proteins in the endoplasmic reticulum of the hepatocyte - most common genetic cause of acute and chronic liver disease in children - most common genetically caused disorder necessitating liver transplantation in children

Answer 36

a1-AT deficiency

Question 37

what causes jaundice in older children/adolescents?

Answer 37

obstructive or hepatocellular causes