Paediatric jaundice Flashcards
When dealing with paediatric jaundice - you must appreciate the age of the baby as this can indicate what the cause of jaundice might be - and also how serious it is
What are causes of early infant jaundice - in a baby less than a day old?
Jaundice in baby < day is always pathological
Can be due to:
Haemolysis
Sepsis
When dealing with paediatric jaundice - you must appreciate the age of the baby as this can indicate what the cause of jaundice might be - and also how serious it is
What are the causes of intermediate infant jaundice - in a baby 1 day - 2 weeks old?
Can be physiological jaundice (ie not pathological)
Can be due to:
- Breast milk jaundice
- Haemolysis
- Sepsis
When dealing with paediatric jaundice - you must appreciate the age of the baby as this can indicate what the cause of jaundice might be - and also how serious it is
What are the main causes of prolonged infant jaundice - in a baby > 2 weeks old?
Extrahepatic obstruction
Neonatal hepatitis
Hypothyroidism
Breast milk jaundice
What is meant by physiological jaundice?
Jaundice that most babies get to some degree - due to a number of things:
- Short RBC lifespan (due to HbF)
- Relative polycythaemia
- Immature liver function (doesnt conjugate v well yet)
This leads to unconjugated jaundice - that is fairly normal but doesnt happen until after 1 day of life
Compare breatsfeeding & formula feeding in the context of jaundice
Breastfeeding typically causes more jaundice and prolongation of jaundice in babies
What are the clinical aspects of breastmilk jaundice?
Failry normal - nobody really knows what causes it
Unconjugated jaundice
Can persist up to 12 weeks
If jaundice is normal in babies and most often due to harmless physiological causes - then why do we assess babies with jaundice?
Kernicterus - a complication of neonatal jaundice (even physiological i think)
What is kernicterus?
Kernicterus = bilirubin-induced brain dysfunction
This happens due to high levels of unconjugated bilirubin crossing the blood brain barrier
Bilirubin is neurotoxic and deposits in the brain - especially in the basal ganglia
Why is it only unconjugated bilirubin that causes kernicterus?
Unconjugated bilirubin is water insoluble - and thus fat soluble
This means it can cross the blood-brain barrier
What are the clinical features of kernicterus?
What are the potential consequences of it?
Encephalopathy:
- poor feeding
- lethargy
- then seizures
Consequences:
- severe choreoathetoid cerebral palsy
- learning difficulties
- sensorineural deafness
What treatment options are available for treatment of unconjugated jaundice of a neonate?
What are the indications for each?
Photo-therapy
Visible light (450nm) causes photoisomerisation of unconjugated bilirubin into a water soluble isomer
This is used when rising unconjugated bilirubin levels are detected - to prevent them getting to a level where kernicterus is a risk
Exchange transfusion
This is the treatment for already very high levels of unconjugated bilirubin - ie just before or at the level causing kernicterus
What are the other causes of early/intermediate unconjugated jaundice in newborns?
Sepsis
Haemolysis:
- ABO or Rhesus incompatible
- Bruising / cephalhaematoma
- Red cell membrane defects - eg Spherocytosis
- Red cell enzyme defects - eg G6PD deficiency
Abnormal conjugation:
- Gilbert’s disease - common but mild
- Crigler-Najar syndrome - rare and severe
How would you investigate the following causes of unconjugated jaundice…
a) Sepsis?
Hameolysis caused by:
- b) ABO or Rhesus incompatibility?
- c) Bruising / cephalhaematoma?
- d) Red cell membrane defects - eg spherocytosis?
- e) “ enzyme defects - eg G6PD deficiency?
a) Sepsis - urine & blood cultures, TORCH screen
Haemolysis caused by:
b) ABO / Rhesus - blood group, Direct Coombs Test (DCT)
c) Bruising / cephalhaematoma - examination
d) Spherocytosis etc - blood film
e) G6PD deficiency etc - G6PD assay or similar
Define prolonged infant jaundice
Any jaundice of the infant lasting beyond 2 weeks of life
(or 3 weeks for preterm)
What are the main causes of prolonged infant jaundice?
What type of jaundice is seen in each
Anatomical (biliary jaundice) - conjugated
Neonatal hepatitis - conjugated
Hypothyroidism - unconjugated
Breast milk jaundice - unconjugated
What is always worrying - conjugated or unconjugated prolonged infant jaundice?
Conjugated prolonged infant jaundice is always pathological - thus always requires further investigation
(that doesnt mean that there all causes of unconjugated prolonged infant jaundice are not pathological and not serious)
What bloods investigation is most important in prolonged infant jaundice?
What else is it important to examine/investigate?
Split bilirubin
Examine stool colour
What are the anatomical causes of prolonged infant jaundice?
What are their main features?
Biliary atresia (mc)*see bottom:
- Conjugated jaundice
- Pale, fatty stools
Choledochal cyst - (cystic dilation of bile ducts):
- Conjugated jaundice
- Pale, fatty stools
Alagille syndrome:
- Intrahepatic cholestasis, dysmorphism, congenital cardiac disease
*Biliary atresia is a serious cause - and should be the first thing you rule out before considering others (incl hepatitis)
What is biliary atresia?
What are its mean clinical features?
Congenital fibro-inflammatory disease of bile ducts leading to destruction of extra-hepatic bile ducts
Prolonged, conjugated infant jaundice
Really pale stools & dark urine
Progression to liver failure - if not treated
Mc cause of liver transplant in infants
What is the treatment for biliary atresia?
Kasai portoenterostomy
Must be done < 60 days
(if progressed to bad liver failure - then transplant i assume)
What are the anatomical causes of prolonged infant jaundice?
For each, describe very briefly the order of investigation needed for diagnosis
Biliary atresia:
- split bilirubin, stool colour, ultrasound, liver biopsy
Choledochal cyst:
- split bilirubin, stool colour, ultrasound
Alagille syndrome:
- dysmorphism, genotyping
Neonatal hepatitis is one of the main causes of prolonged infant jaundice
What are the many causes of neonatal hepatitis?
What test diagnoses each?
Horrible card
Alpha-1-antitrypsin deficiency - phenotype/level
Galactosaemia - GAL-1-PUT
Tyrosinaemia - amino acid profile
Urea cycle defects - ammonia
Haemochromatosis - iron studies, liver biopsy
Glycogen storage disorders - biopsy
Hypothyroidism - TFTs
Viral hepatitis - serology, PCR
Parenteral nutrition - history
