Paediatric Jaundice Flashcards
What functions does the liver have?
- makes clotting factors
- metabolism e.g. absorption, digestion materials produced
- storage of glycogen etc
- filter for the body
What are the liver function tests?
- bilirubin (total or split)
- ALT/AST (alanine aminotransferase/ aspartate aminotransferase)
- alkaline phosphatase
- gamma glutamic transferase (GGT)
What do the transaminases tell you about the liver?
- that there is hepatocellular damage
- also can be an indicator of cardiac or muscle damage
What does alkaline phosphatase tell you about the liver?
that there is biliary inflammation
What is the best test to assess liver function?
coagulation tests i.e. prothrombin time/ INR or APTT (activated partial thromboplastin time)
What are other good tests of liver FUNCTION?
- albumin
- bilirubin
- (blood glucose)
- (ammonia)
What is the main clinical manifestation of paediatric liver disease?
jaundice - especially in young babies
What are 2 other ways that paediatric liver disease might present?
- incidental finding of abnormal blood test
- symptoms/signs of chronic liver disease (rare)
What are signs of chronic liver disease in children?
- growth failure
- jaundice
- encephalopathy
- varices with portal hypertension
- spider nave
- muscle wasting from malnutrition
- bruising and petechiae
- splenomegaly with portal hypertension
- hepatorenal failure
- clubbing
- loss of fat stores
- rickets secondary to vit. D deficiency
- ascites
- hypotonia
- peripheral neuropathy
How can you identify jaundice?
yellowy discolouration of skin and tissues, including the sclera
When does jaundice usually become visible?
when total bilirubin >40-50umol/l
What is the diagnosis of infant jaundice dependent on?
- understanding bilirubin metabolism
- age of the infant
Bilirubin metabolism.
Breakdown of RBCs get unconjugated bilirubin.
Unconjugated bilirubin transported bound to albumin to liver.
Liver conjugates bilirubin using UDP glucuronyl transferase.
Conjugated bilirubin carried in bile to small intestine.
Some conjugated bilirubin gets excreted in faeces and urine. Rest gets taken up by enterohepatic circulation again.
What kind of bilirubin would you find in pre-hepatic jaundice?
mostly unconjugated
What kind of bilirubin would you find in intrahepatic jaundice?
mixed unconjugated/ conjugated
What kind of bilirubin would you find in post-hepatic (cholestasis) jaundice?
mostly conjugated
What are the 3 classifications of neonatal jaundice?
- early
- intermediate
- prolonged
What age range would class neonatal jaundice as early? What would cause it? Is it serious?
- happens in neonates <24 hours old
- ALWAYS pathological
- caused by haemolytic, sepsis
What age range would class neonatal jaundice as intermediate? What would cause it? Is it serious?
- happens in neonates between 24 hours and 2 weeks old
- may be pathological
- can be caused by normal physiology, breast milk, sepsis, haemolytic etc
What age range would class neonatal jaundice as prolonged? What would cause it? Is it serious?
- happens in neonates over 2 weeks old
- may be pathological and must be investigated
- can be caused by extra hepatic obstruction, neonatal hepatitis, hypothyroidism, breast milk
Why can a baby have ‘physiological’ jaundice?
- shorter RBC life span in infants
- have a relative polycythaemia (lots of RBCs) so make lots of unconjugated bilirubin
- relative immaturity of liver function in neonates might mean that the liver cannot handle all of the bilirubin, so get jaundiced
- is a form of unconjugated jaundice
What are features of breast milk jaundice?
- physiological jaundice in child who is breastfeeding
- prolonged physiological jaundice
- can last up to 12 weeks
- unconjugated jaundice
What are other causes of early/ intermediate unconjugated infant jaundice?
- sepsis
- haemolysis e.g. after traumatic birth getting rid of a bruise or cephalhaematoma or having a red cell enzyme defect (G6P deficiency)
- abnormal conjugation
What is a serious complication of unconjugated jaundice?
kernicterus
What is kernicterus?
when unconjugated bilirubin crosses the blood brain barrier and leaves deposits in the brain (particularly basal ganglia) that are neurotoxic
What are early signs of kernicterus?
- encephalopathy
- poor feeding
- lethargy
- seizures
What are late consequences of kernicterus?
- severe choreoathetoid cerebral palsy
- learning difficulties
- sensorineural deafness
How can the unconjugated jaundice be treated?
phototherapy with blue light
How do we decide if a child will benefit from phototherapy?
treatment threshold graph for babies with neonatal jaundice
What classifies infant jaundice as ‘prolonged’?
- jaundice persisting beyond 2 weeks of life
- beyond 3 weeks of life for preterm infants
What can cause a conjugated prolonged infant jaundice?
- neonatal hepatitis
- anatomical(biliary obstruction)
What can cause an unconjugated prolonged infant jaundice?
- hypothyroidism
- breast-milk jaundice
What is important to note about conjugated jaundice in infants?
it is ALWAYS abnormal and ALWAYS requires further investigation
What is the most important test in prolonged jaundice?
a split bilirubin test
What is the most common cause of conjugated prolonged jaundice?
biliary atresia
What are 2 other obstructive causes of conjugated prolonged jaundice?
- choledochal cyst
- alagille syndrome (intahepatic bile duct problem)
What would you notice about the stools in conjugated obstructive jaundice?
they would be pale
What is the most common type of conjugated infant jaundice that we must be aware of and identify?
biliary atresia
What is biliary atresia?
congenital fibre-inflammatory disease of the bile ducts leading to destruction of extra hepatic bile ducts
How does biliary atresia present?
- prolonged, conjugated jaundice
- pale stools, dark urine
Why is it important to recognise and treat biliary atresia?
- there can be progression to liver failure if not identified and treated
- timely diagnosis as time to treatment determines prognosis
- most common indication forever transplantation in children
How can biliary atresia be treated?
kasai portoenterostomy (surgeon replaces her damaged bile ducts with a piece of her intestine. This allows bile to drain directly from the small bile ducts at the edge of your child’s liver straight into her intestine.)
What is the important time frame for performing a kasai portoenterostomy?
best results if performed before 60 days (<9 weeks) as inflammation can progress too much beyond this time
What is the assessment of prolonged infant jaundice primarily targeted at?
diagnosing patients with biliary atresia early on
How can biliary atresia be diagnosed?
- split bilirubin to confirm conjugated jaundice
- stool colour (pale)
- US may show damaged extra hepatic biliary ducts
- liver biopsy
How can a choledochal cyst leading to prolonged jaundice be diagnosed?
- split bilirubin to identify conjugated jaundice
- stool colour
- US
How can Alagille syndrome be identified?
- dysmorphism
- genotype
Neonatal hepatitis can cause prolonged conjugated jaundice. What can cause neonatal hepatitis?
- Alpha-1-antitrypsin deficiency (adults lung disease, children gut disease)
- Galactosaemia
- Tyrosinaemia
- Urea cycle defects
- Haemochromatosis
- Glycogen storage disorders
- Hypothyroidism
- Viral hepatitis
- Long term parenteral nutrition
