Neonatal Jaundice Flashcards
What is a neonate
Any newborn from birth to 28 days of life
What is Jaundice (icterus)
Yellowing discoloration of skin and sclera
Why does bilirubin get conjugated in the liver by glucuronyltramsferase
To go from lipid soluble to water soluble to be excreted
Main cause of jaundice in neonates
Premature hemolysis of rbc
Biliverdin acted on by NADPH to form indirect bilirubin
Indirect Bilirubin carried to liver by albumin
Gilbert syndrome
Genetic condition with slow activity of glucuronyltransferase
Crigler najjarsyndrome
No enzyme at all , bad prognosis in first few months
Types of jaundice in neonate
Physiological
Pathological
Breastfeeding
Pathophysiology of physiologic jaundice
2 simultaneous mechanisms :
Low glucuronyltransferase (uridine diphosphate (UDP)-glucuronosyltransferases (UGT))
Bilirubin conjugated into the liver -> The bile containing bilirubin gets deposited into the duodenum ->
Within proximal small intestine , Beta glucoronidase can deconjugate the conjugated bilirubin ->
Deconjugated bilirubin reabsorbed into blood circulation Increasing blood bilirubin level -> goes again into the liver
ENTEROHEPATIC CIRCULATION
Breastfeeding jaundice
Feeding of baby increases peristalsis
So if no food , bile will stay longer in the intestines because of lack of peristalsis
So beta glucoronidase act longer on it so more bilirubin in circulation
Breast milk jaundice
Component in breast milk compete with bilirubin for conjugation binding site leading to more bilirubin in the circulation
Physiological jaundice time of onset and progression
From 2nd day of life
Peak on 3rd-5th
Resolved by 14th day
Can high level of unconjugated bilirubin cross the BBB
Yes
What is bilirubin encephalopathy
How do you call when you see
Kernicterus
