Paediatric Liver and Infant Nutrition Flashcards
How do signs of chronic liver disease alter in paediatrics compared to adult?
Same signs but additionally there is growth failure
Where is it best to check for jaundice and why?
The sclera
Yellowing of the skin such as beta carotenaemia can occur but will not affect the sclera so sclera good for differentiating
Briefly describe the metabolism of bilirubin
Post-mature erythrocytes are broken down to unconjugated bilirubin, which is transported to the liver where it is conjugated. It is then excreted through the bile into the small intestine and passed through the stool
How does a split bilirubin help narrow down the location of the cause?
Split bilirubin gives levels of unconjugated and conjugated bilirubin separately.
•Mainly unconjugated bilirubin- pre-hepatic
•Mixed unconjugated and conjugated- hepatic
•Mainly conjugated- post-hepatic
What are the causes of early jaundice in the first 24hrs of life?
Always pathological, usually caused by haemolysis or sepsis
What is the definition of intermediate jaundice?
Intermediate jaundice is jaundice between 24hrs and 2 weeks of life
What are the causes of intermediate jaundice?
Physiological
Breast milk
Sepsis
Haemolysis
What is the definition of prolonged jaundice?
Jaundice occurring from two weeks of life onwards or three weeks in preterm infants
What are the causes of prolonged jaundice?
Extrahepatic obstruction
Neonatal hepatitis
Hypothyroidism
Breast milk jaundice
What is physiological jaundice?
Unconjugated jaundice that onsets after the first day of life
What are the causes of physiological jaundice?
Shorter red blood cell lifespan in infants
Relative polycythaemia
Relative immaturity of liver function
What is breast-milk jaundice?
Unconjugated jaundice that persists in breast-fed infants for up to 12 weeks for unknown reasons
What are the other causes of early/intermediate unconjugated infant jaundice other than physiological or breast fed?
Sepsis
Haemolysis- ABO incompatibility, rhesus disease, red cell defects
Abnormal conjugation- Gilbert’s disease (common, mild), Crigler-Najjar syndrome (very rare but serious)
What tests can be useful in investigating causes of early/intermediate jaundice?
Urine + blood cultures TORCH screen Blood group Direct Coombs test Blood film G6PD assay Genotype/phenotype testing
What is kernicterus?
An important complication of early infant jaundice
Why does kernicterus develop?
As unconjugated bilirubin is fat soluble it can cross the blood-brain barrier and leave neurotoxic deposits in the brain. It can be a complication of any kind of jaundice, even physiological
What are the early signs of kernicterus?
Encephalopathy related- poor feeding, lethargy and seizures
What are the late signs of kernicterus?
Severe choreoathetoid cerebral palsy
Learning difficulties
Sensorineural deafness
How is unconjugated jaundice treated?
Phototherapy using visible light of a 450nm wavelength that converts bilirubin to a water soluble isomer
What are the causes of prolonged jaundice?
Conjugated: •Anatomical- biliary obstruction •Neonatal hepatitis Unconjugated: •Hypothyroidism •Breast-milk jaundice
What biliary obstructions can cause prolonged jaundice?
Biliary atresia- conjugated jaundice + pale stools
Choledochal cyst- conjugated jaundice + pale stools
Alagille syndrome- intrahepatic cholestasis, dysmorphism, congenital cardiac disease
What additional step should be taking when assessing infant jaundice?
Always assess stool colour
What is biliary atresia?
A congenital fibro-inflammatory disease of the bile ducts that leads to destruction of the extra-hepatic bile ducts
What are the symptoms of biliary atresia?
Patients present with prolonged, conjugated jaundice and will have pale stools and dark urine. It will progress to liver failure if it is not identified and treated
