The Yellow Baby Flashcards
What are the LFTs?
Bilirubin - total/split
ALT/AST ratio
Alkaline phosphatase
GGT
What is ALT/AST ratio a marker of?
Hepatic damage
>2 in alcoholic liver disease
What is alkaline phosphatase a marker of?
Raised in biliary disease but also raised in pregnancy and diseases where there is increase osteoblast activity
What is GGT a marker of?
Biliary disease but also alcoholic liver disease
To actually assess liver function what tests are better?
Coagulation - PT/INR/APTT
Albumin
Bilirubin
Blood glucose & ammonia sometimes
What does PT measure?
Vit K dependent clotting factors - 1, 2, 5, 7, 10
What does APTT measure?
Other clotting factors
What does high albumin suggest?
Dehyration
What does low albumin suggest?
Protein loss or liver dysfunction
How can liver disease manifest in children?
Signs/symptoms
Jaundice
Incidental abnormal blood test
What are the signs and symptoms of liver disease?
Oestrogen related ones: spider naevi, liver palms etc.
Portal HTN, varices, splenomegaly, hypersplenism, ascites
Ammonia related encephalopathy
Hepatorenal failure
Malabsorption, rickets
Clotting factor related ones: petechiae/bruising/epistaxis
Peripheral neuropathy, hypotonia
Define jaundice
Yellow discolouration of skin and other tissues due to accumulation of bilirubin
At what total bilirubin level does jaundice usually become visible
> 40-50umol/l
Where is jaundice most visible?
Sclera
Describe the bilirubin metabolism pathway
Post-mature erythrocytes broken down by RES into haem
Haem broken down into biliverdin
Biliverdin broken down into unconjugated bilirubin by biliverdin reductase
UC bilirubin travels to liver attached to albumin
Liver conjugates bilirubin with UDP glucuronyl transferase
Conjugated bilirubin transformed into bile and then urobilinogen in the small intestine
Can be reuptaken by enterohepatic circulation or excreted by kidneys/gut
In gut becomes stercobilin (responsible for colour of shit)
How is neonatal jaundice classified?
Age
Early (<24h) - always pathological
Immediate (24h-2wks)
Prolonged (>2wk)
What are the causes for early jaundice?
Sepsis, haemolysis
What are the causes for immediate jaundice?
Sepsis, haemolysis, physiological jaundice, breast milk jaundice
What are the causes for prolonged jaundice?
Extrahepatic obstruction, neonatal hepatitis, breast milk jaundice, hypothyroidism
What is physiological jaundice?
RBCs have shorter lifespan in infants (80-90d) so relative polycythaemia & relative immaturity of liver function –> unconjugated jaundice
What is the mechanism behind breast milk jaundice?
We don’t entirely know - perhaps inhibition of UDP by progesterone metabolite or increased enterohepatic circulation –> unconjugated jaundice
How long can breast milk jaundice last for?
Up to 12 weeks
What are causes for haemolysis in early/immediate unconjugated infant jaundice?
ABO incompatibility Rh disease Bruising/cephalhaematoma Red cell membrane defect, e.g. spherocytosis Red cell enzyme defect, e.g. G6PD
What two other conditions can cause immediate/early unconjugated infant jaundice?
Gilbert’s disease - common & mild
Crigler-Najjar syndrome - v. rare & serious (UDP deficiency)
What tests would you do if you suspected sepsis?
Blood culture/urine culture
ToRCH screen
What tests would you do if you suspected ABO incomptability/Rh disease?
Blood group, DCT
What tests would you do if you suspected gilbert’s/crigler-Najjar syndrome?
Genotype/phenotype
What is kernicterus?
Unconjugated bilirubin is fat soluble can cross BBB and accumulate in brain
It is neurotoxic
What are the early signs of kernicterus?
Lethargy, seizures, poor feeding (encephalopathy)
What are the late signs of kernicterus?
Severe choreoatheoid cerebral palsy, learning difficulties, sensorineural deafness
How do you treat unconjugated jaundice?
Phototherapy - visible light at 450nm changes bilirubin into water soluble isomer
May need exchange transfusion if more premature/higher level of bilirubin
Define prolonged infant jaundice
Jaundice lasting more than 2 weeks (or 3 weeks in prems)
What can cause prolonged infant jaundice?
Anatomical (biliary tree obstruction)
Neonatal hepatitis
Hypothyroidism
Breast milk jaundice
Conjugated jaundice is always what?
Abnormal and requires further Ix
What are the biliary obstructions that can cause conjugated prolonged jaundice?
Biliary atresia - CJ, pale stools
Choledochal cysts - CJ, pale stools
Alagille syndrome - intrahepatic cholestasis, facial dysmorphism, congenital cardiac dx
What is biliary atresia?
Congenital fibro-inflammatory disease of bile ducts leading to destruction of extra-hepatic bile ducts
What is the presentation of biliary atresia?
Pale stools, CJ, dark urine
Can progress to liver failure if not Ix and Rx
How do you Rx biliary atresia?
Kasai portoenterostomy (within 60 days for best results)
What investigations would you do for biliary atresia?
Split bilirubin, stool colour, USS, liver biopsy
What Ix would you do for choledochal cyst?
Split bilirubin, stool colour, USS
What Ix do you do for Alagille syndrome?
Genotyping
What are other rarer causes of prolonged infant jaundice?
Alpha-1-antitryspin deficiency Galactosaemia Tyrosinaemia Urea cycle defects Haemachromatosis Glycogen storage disorders Hypothyroidism Viral hepatitis Parenteral nutrition
What test do you do for galactosaemia?
GAL-1-PUT
What test do you do for trysoniaemia?
Amino acid profile
What test do you do for urea cycle defects?
Ammonia
What tests do you do for haemochromatosis?
Iron studies, liver biopsy
What tests do you do for glycogen storage disorders?
Biopsy
