Neonatal Jaundice

Question 1

what causes physiologic jaundice

Answer 1

increased bilirubin production secondary to accelerated destruction of RBCs

decreased excretory capacity secondary to low levels of ligandin in hepatocytes, and low activity of the bilirubin conjugating enzyme UDPGT

also jaundice of prematurity

breastfeeding jaundice

Question 2

when does physiologic jaundice appear

Answer 2

day 2

peaks days 2-5

disappears after day 7 in term babies and day 14 in premature babies

Question 3

what causes pathologic neonatal jaundice with unconjugated bilirubin (direct)

Answer 3

1. increased production
   - -hemolytic diseases like Rh-isoimmunization, intrinsic membrane defect
   - -infection
   - -extravasated (i.e from bruising or cephalohematoma)
   - -enterohepatic circulation increases (i.e from dehydration, GI obstruction)
   - -polycythemia
2. decreased conjugation
   - -syndromes like Kriegler Najjar Gilbert

Question 4

what causes pathologic neonatal jaundice with conjugated bilirubin (indirect)

Answer 4

1. intrahepatic cholestasis
   - -persistent, like in neonatal hepatitis
   - -acquired like infections or drug induced
   - -metabolic or genetic disorders like alpha 1 antitrypsin deficiency
2. extrahepatic obstruction
   - -i.e biliary atresia or choledocal cyst
3. metabolic disorders
   - -disorders of carbohydrate or amino acid metabolism like galactosemia, gaucher disease etc

Question 5

a baby develops jaundice within the first 24 hours of life. is this pathologic

Answer 5

yes

all jaundice within first 24 hours is pathologic

Question 6

first line investigations for neonatal jaundice

Answer 6

bilirubin total and direct

blood groups and Rh

Coombs test

CBC

peripheral smear

reticulocyte count

Question 7

second line tests for neonatal jaundice

Answer 7

septic workup–cultures, CXR

screen for inborn errors of metabolism

screen for hypothyroid

alkaline denaturation of HgB

PT, pTT

HgB electrophoresis

Question 8

how do you treat jaundice

Answer 8

phototherapy

photoisomerizes bili to water soluble product excreted by the kidneys

Question 9

what are common conditions causing neonatal jaundice

Answer 9

unconjugated hyperbilirubinemia from breastfeeding jaundice/ breast milk jaundice (physiologic)

Question 10

what causes of neonatal jaundice have high mortality/morbidity

Answer 10

biliary atresia

acute bilirubin encephalpathy

sepsis

Question 11

what are some intrinsic hemolytic causes of unconjugated neonatal jaundice

Answer 11

red cell membrane defects like spherocytosis, elliptocytosis

ethrythrocyte enzyme defects like G6PD deficiency, pyruvate kinase deficiency, and congenital erythropoietic porphyria

hemoglobinopathies like alpha thalassemia

Question 12

what are red flags for neonatal jaundice

Answer 12

onset in first 24 hours

prolonged beyond 1-2 weeks

pale stools

dark urine

hyper or hypotonia

dehydration

Question 13

what to ask on ROS for neonatal jaundice

Answer 13

hypo or hypertonia
seizures
decreased LOC
cough/wheeze
apnea
respiratory distress
abdominal distension
bleeding
rash or lesions

Question 14

risk factors for neonatal jaundice

Answer 14

ABO incompatibility
prematurity
sibling with severe hyperbili
birth trauma
male
mother older than 25
asian or european ethnicity
infetion
breastfeeding
macrosomic infact of diabetic mother
poor feeding
TPN
sepsis risk factor (GBS+, PROM/PPROM, chorio)

Question 15

what is a very mundane but important cause of neonatal jaundice

Answer 15

dehydration

Question 16

when should you perform an exchange tansfusion to manage neonatal jaundice

Answer 16

if signs of acute bilirubin encephalopathy –this is rare

Question 17

should breast feeding be stopped for breast feeding jaundice

Answer 17

no

Question 18

how do you manage immune hemolytic jaundice

Answer 18

IVIG and consider exchange transfusion

Question 19

how do you manage mild to moderate unconjugated hyperbili

Answer 19

phototherapy using normogram

Question 20

how do you manage biliary atresia

Answer 20

consult peds surg