3 - Paeds - Gastro - Jaundice Flashcards Preview

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Flashcards in 3 - Paeds - Gastro - Jaundice Deck (17):

why are >50% of newborns visibly jaundiced

-marked physiological release of Hb from breakdown of RBCs (high Hb conc at birth)
-newborns RBC lifespan only 70d
-hepatic bilirubin metabolism less efficient in first few days


Neonatal jaundice important to deal with because???

-unconj bilirubin can deposit in basal ganglia - causing kernicterus
-sign of other disorder eg haemolytic anaemia, infection, metab disease, liver disease


Kernicterus - encephalopathy due to? occurs when?

unconj bilirubin deposition in BG and brain stem nuclei

when unconj bilirubin level exceeds albumin binding capacity - free bilirubin can then cross BBB.


clinical features of kernicterus - pre-severe? if severe?

lethargy, poor feeding

if severe - irritability, incr muscle tone -> arched back, seizures, coma


Infants who survive kernicterus may develop which 3 things?

sensorineural deafness
choreoathetoid cerebral palsy


describe the bilirubin pathway or conjugation etc

Hb breakdown > unconj bili bound to albumin > enters liver > conjugated > excretion in bile
conj bili (water sol) give urine and stools darkness


causes of unconj jaundice (5)

breast milk jaundice (physiological), infection (UTI), Hypothyroidism, Haemolytic anaemia (G6PD def), high GI obstruction (PS)


Causes of conjugated jaundice (3)

bile obstruction (biliary atresia, choledochal cyst)
neonatal hepatitis syndrome (CF, a1 Antitrypsin def, congenital infection)
Intrahepatic biliary hypoplasia


What suggests conj jaundice

dark urine and pale stools
hepatomegaly and poor wt gain also


Classification by age - causes

<24h - usually haemolysis - important to ID before unconj bili levels get too high
2d-2wks - physiological
>2wks (persistent/prolonged neonatal jaundice) - ?biliary atresia - usually unconj due to breast milk/infection/congenital hypothyroidism


Haemolytic disorders causing EARLY jaundice (4)

rhesus disease - usually dealt with antenatally
ABO incompatibility - less severe than Rh
G6PD def - mainly ethnic males
Spherocytosis - FHx, spherocytes on blood film


Features of congenital infection causing jaundice

conj bili
infants have other signs eg growth restriction, hepatosplenomegaly, thrombocytopenic purpura


2d - 2wk jaundice - 3 causes

breast milk jaundice (inc enterohepatic circ of bii)
Dehydration (poor intake/delay)
Infection (unconj from poor fluid intake, haemolysis, reduced hep function + inc enterohepatic circ)

other - crigler najjar


Ix to do initially?

inspection in bright natural light -> sclera, gums, blanched skin (starts on head > trunk/limbs)
Stool colour - pale = biliary tree/post hepatic obstruction of conj bili


Ix to do once seen jaundice O/E? what to consider in ethnic/preterm babies?

measure with transcutaneous meter or blood sample - a high TC measurement must be checked with bloods

preterm/ethnic have lower threshold


MGMT - initially? then? when to step up? to what?

correct poor intake/dehydration
then phototherapy
step up if bili reached dangerous levels - to Exchange transfusion (continue phototherapy)


What can phototherapy cause? what if bili rising?

can cause macular rash and bronze discolouration if conj jaundice - if rising, give continuously

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