Hyperbilirubinemia in the newborn. Flashcards
(46 cards)
where does haemoglobin get catabolised ?
in the reticuloendothelial system
how much more bilirubin do newborn produce compared to adults
two to 3 times moe
what is the cause of increased bilirubin production in newborns ?
increased RBC , or hematocrit ,
shorter erythrocyte life span
inefficient erythropoesi
decreased albumin binding = lower albumin con
decreased ligandin so less hepatic uptake
decreased secretion
indirect bilirubin is particularly harmful to which part of the body
toxic to the CNS
what can increase indirect bilirubin rather than liver and spleen and reticuloendothelial probes
organic acids such as fatty acids and drugs can displace the bilirubin from albumin
which enzyme represents the rate limiting step of bilirubin conjugation
glucuronosyltransferase
for hepatic conjugation to occur bilirubin myst dissociate from albumin and bind to which liver protein
ligandin
conc of ligandin and glucuronosyltransferase is particularly low in whom
newborn and preterm
can indirect bilirubin cross the placenta
yes it can cross the placenta and become conjugated by the maternal hepatic enzymes
clinical pattern of physiological jaundice is what
hyperbilirubinemia can start no before than 24 hrs and no more than 12MG/DL in the 3rd day of life
in preterm = 15mg/dl in the fifth day of life
jaundice is unphysiological if what ?
appears on the first day of life
bilirubin levels increases more than 0.5MG/DL/HR
if the peak bilirubin is greater than 13mg/dl in term infants
if direct bilirubin fraction is greater than 1.5MG/DL
heaptosplenomegaly and anemia is present
what is crigler-najjar syndrome ?
autosomal dominant disease
or autosomal recessive
rare but permanent deficiency of gluconosyltransferase
what can treat AUTOSOMAL DOMINANT crigler-najjar syndrome ?
some variety respond to enzyme induction by phenobarbitural = producing and increase in enzyme activity and reduction of bilirubin lives
what can treat autosomal recessive format of the crigler-najjar syndrome ?
it does not respond to phenobarbitutal and manifest as perisirant indirect hyperbilirubinemia
what is gilbert disease ?
mutation of the promoter region of glucuronsyltransferase = mild indirect hyperbilirubinemia results
if gilbert disease was concomitant with what other disease can lead to severe jaundice formation
other icterogenic factor such as hemolysisi
breast milk jaundice have appearance when in a baby’s life
first or second week
what is a sign and symptom of breast milk jaundice ?
bilirubin rarely increases more than 20mg/dl and interruption of breast feeding for 1 or 2 days results in rapid decline of bilirubin which do not increase significantly after breastfeeding resumes
why is there breast milk jaundice ?
breast milk may contain the inhibitor of bilirubin conjugation
increase the enterohepatic recirculation of bilirubin because of breast milk glucuronidase
early onset of jaundice scubas in the first days are due to ?
hemolytic diseases
internal haemorrhage = cephalohematoam ,, hepatic or splenic hematoma
OR infection sepsis
delayed cord clamping
Inherited red cell enzyme, membrane defects
(e.g., spherocytosis, glucose 6-phosphate-dehydrogenase deficiency,
physical evidence of jaundice is brough about when bilirubin levels reach what level
5-10mg/dl
unlike 2 mg/dl in adults
bilirubin greater than what in first day of life and second day of life should be evaluates
first day of life greater than 5mg/dl
second day greater than 13mg/dl
what are the diagnostic pathways to determine the etiology of the bilirubin
test direct and indirect bilirubin levels
Coombs test - for autoimmune haemolytic anemia
complete blood count
blood smear
reticulocyte count
what are the hemolysis absent causes of jaundice which is common
physiological
breast milk
internal haemorrhage
polycethma in diabetic mother
Mutations of glucuronyl transferase enzyme (Crigler- Najjar syndrome,
Gilbert isease),
pyloric stenosis, hypothyroidism
