approach to the yellow baby Flashcards
ALT/AST
what do they stand for
alanine aminotransferase/aspartate aminotransferase
elevated ALT/AST
hepatocellular damage - hepatitis
typical ways in which liver disease presents in children
jaundice
incidental finding on blood test
rare - other symptoms/signs of CLD
jaundice
yellow discolouration of skin and tissues due to accumulation of bilirubin
usually visible when total bilirubin >40-50 umol/l
pre-hepatic jaundice
mostly unconjugated bilirubin
increased breakdown RBC and so too much unconjuagted bilirubin
intrahepatic jaundice
mixed unconjugated/conjuagted
problem with liver, it’s not conjugating the bilirubin as much as it should be and also not excreting it effectively into bile
post-hepatic jaundice (cholestasis)
mostly conjugated bilirubin
problem lies with bile being able to get out of liver and getting to small intestine to be excreted. obstruction/blockage stopping bilirubin getting out of liver/bile ducts
neonatal jaundice: early (<24hrs old)
always pathological
causes: haemolysis, sepsis
neonatal jaundice: intermediate (24hrs-2wks) causes
physiological
breast milk
sepsis
haemolysis
neonatal jaundice: prolonges (>2wks) causes
extrahepatic obstruction
neonatal hepatitis
hypothyroidism
breast milk
physiological jaundice
shorter RBC lifespan in infants (80-90 days)
relative polycythaemia
relative immaturity of liver function
unconjugated jaundice
develops after 1st day of life
breast milk jaundice
exact reason unclear - inhibition of UDP by progesterone metabolite? increased enterohepatic circulation?
unconjugated jaundice
can persist up to 12wks
kernicterus
unconjugated bilirubin is fat-soluble (water insoluble) so can cross blood-brain barrier
neurotoxic and deposits in brain
kernicterus signs
early signs: encephalopathy - poor feeding, lethargy, seizures
late consequences - severe choreoathetoid cerebral palsy, learning difficulties, sensorineural deafness
phototherapy
treatment for unconjugated jaundice
visible light (not UV) converts bilirubin to water soluble isomer (photoisomerisation)
other causes of early/intermediate unconjugated infant jaundice
sepsis
haemolysis: ABO incompatibility, Rhesus disease, red cell membrane defects
abnormal conjugation - Gilbert’s disease
prolonged infant jaundice
jaundice persisting beyond 2 weeks of life (3wks for preterm infants)
causes of prolonged infant jaundice: conjugated
anatomical (biliary obstruction)
neonatal hepatitis
causes of prolonged infant jaundice: unconjugated
hypothyroidism
breast-milk jaundice
what is most important test in prolonged jaundice
split bilirubin
causes of prolonged infant jaundice: biliary obstruction
biliary atresia: conjugated jaundice, pale stools
choledochal cysts: conjugated, pale stools
alagille syndrome: intrahepatic cholestasis, dysmorphism, congenital cardiac disease
what always needs assessed in infants with prolonged jaundice
stool colour
biliary atresia
congenital fibro-inflammatory disease of bile ducts leading to destruction of extra-hepatic bile ducts
presents with prolonged, conjugated bilirubin
pale stools, dark urine
biliary atresia treatment
kasai portoenterostomy
best results if performed before 60 days (<9wks)
