Neonatal Jaundice

Question 1

Value of jaundice is detectable at?

Answer 1

85 - 120 umol

Question 2

Explain the process of the breakdown of hemoglobin

Answer 2

Haem - Bilverdin - bilirubin

globin - amino acids

Question 3

What removes most bilirubin in a fetus?

Answer 3

placenta

Question 4

Why is neonatal jaundice more common in breastfed infants rather than formula-fed ones?

Answer 4

enterohepatic circulation still exists after birth and therefore conjugated bilirubin is deconjugated by beta glucoronidase (which is the enzyme found in breast milk), therefore unconjugated bilirubin is reabsorbed

Question 5

what is the responsibility for the enzyme glucoronyl transferase?

Answer 5

this enzyme aids in the conjugation of bilirubin with glucuronic acid and assists the bilirubin to be broken down by the gut into stercobilin (by bacteria)

Question 6

Why does physiological jaundice usually appear?

Answer 6

• accelerated RBC breakdown
• reduced liver conjugation ability
• increased enterohepatic circulation

Question 7

Why is jaundice common in neonates vs adults? [4]

Answer 7

• greater bilirubin production
• more RBCs
• shortened RBC life span
• lower concentration of liver enzymes

Question 8

Why is free unconjugated bilirubin dangerous? [2]

Answer 8

fat-soluble

stops mitochondrial activity

Question 9

Kernicterus?

Answer 9

tissue damage that results from high levels of bilirubin and is only seen on autopsy

Question 10

Risk of bilirubin encephalopathy? [5]

Answer 10

• high levels of serum unconjugated bilirubin
• low serum albumin
• very early jaundice
• competition for binding sites by drugs eg. salicylates, sulphonamides, NEFA (caused by hypothermia)
• opening up of BBB due to hypoxia, acidosis or infection

Question 11

Clinical Presentation of bilirubin encephalopathy [6]

Answer 11

• severe jaundice
• lethargy with poor feeding and depressed moro reflex
• high pitched cry with increased tone
• progression to opisthotonous and convulsions
• setting sun eye appearance
• death

Question 12

what are the consequences of bilirubin encephelopathy?

Answer 12

development of athetoid cerebral palsy

Question 13

Name the causes of pathological jaundice using textbook reference and indirect vs direct

Answer 13

unconjugated [5] vs conjugated jaundice [5]

Question 14

which special investigations should be done?

Answer 14

blood group, coombs test, Hb, CRP

Question 15

what is hydrops fetalis?

Answer 15

trio:

• hemolysis
• anemia
• cardiac failure

Question 16

what can you use to delay hemolysis

Answer 16

IV gamma globulin

Question 17

clinical features of haemolytic disease to Rh incompatibilty

Answer 17

• pale large placenta
• anaemia
• jaundice
• hepatosplenomegaly
• blueberry muffin rash d/t extramedullary erythropoeisis

-

Question 18

Infection increases which type of jaundice

Answer 18

both

Question 19

3 causes of prolonged jaundice

Answer 19

• breast milk jaundice
• hypothyroidism
• infection - very common cause

Question 20

late onset jaundice [2]

Answer 20

• galactossemia

- obstruction