Approach to the yellow baby (LIVER) Flashcards
What are the functions of the liver?
- Produces many of the important enzymes & proteins (clotting factors)
-Absorption, digestion and metabolism-need bile to help you absorb fat - Stores Glc as glycogen, albumin etc
- Clearance of toxic products-metabolism and excretion
What is included in LFTs?
- Bilirubin (total and split bilirubin (direct (conjugated) +indirect (unconjugated))
- ALT/AST
- Alkaline phosphatase
- GGT
What causes a change in ALT/AST?
Elevated in hepatocellular damage (hepatitis)
What LFTs indicate biliary disease?
ALP &/or GGT elevated
What LFTs indicate biliary disease?
ALP &/or GGT elevated
What rises when there is a problem in liver which stops the flow of bile from the liver?
BILIRUBIN
If truly want to test the function of the liver what can be used?
- Coagulation (PT/INR, APTT)
- Albumin
- Bilirubin-bile clearance
(Damage - BG (hypoglycaemia), Ammonia(elevated))
What are the clinical manifestations of paediatric liver disease?
JAUNDICE
Incidental finding of abnormal blood test
Symptoms/signs of chronic liver disease (same as adults + growth failure)
What is jaundice and when is it usually visible?
Yellow discolouration of skin & tissues due to accumulation of bilirubin
Usually most obvious in sclera (distinguishes between true jaundice and beta carotene anaemia)
Usually visible when total bilirubin >40-50umol/l
What is pre-hepatic jaundice?
Refers to any cause of jaundice where the problem lies before the liver
MOSTLY UNCONJUGATED
When there is a problem in the liver itself what jaundice can occur?
Intrahepatic jaundice
Mixed=unconjugated/conjugated
What is post hepatic jaundice also known as?
Cholestasis-obstructive process stopping bile getting out
MOSTLY CONJUGATED
Neonatal jaundice can be classified by age: what are these classifications?
Early (<24hrs old) - Always pathological
- Haemolysis, sepsis
Intermediate (24hrs-2 weeks)
- Physiological, breast milk, sepsis, haemolysis
Prolonged (>2 weeks)
- Extrahepatic obstruction, neonatal hepatitis, hypothyroidism, breast milk
Why do get ‘physiological’ jaundice?
Shorter RBC life span in infants (80-90 days)
Relative polycythaemia
Relative immaturity of liver function
- Unconjugated jaundice
- Develops after 1st day of life
Do we know why breast fed infants jaundice is more likely to last longer than formula fed babies?
Exact reason for the prolongation of jaundice in breastfed infants is unclear
Breast fed infants also more likely to get jaundice
- Unconjugated jaundice
- Can persist up to 12 weeks
Can kernicterus only happen with high levels of unconjugated jaundice?
YESSSSSSS
What causes kernicterus and what are the signs of it?
Unconjugated bilirubin is fat soluble (water insoluble) so can cross BBB-neurotoxic and deposits in the brain
Early signs=encephalopathy-poor feeding, lethargy, seizures
Late consequences-severe choreoathetoid CP, learning difficulties, sensorineural deafness
What is the treatment for unconjugated jaundice?
Phototherapy- NOT UV is just visible light - converts bilirubin to water soluble isomer (photoisomerization)
Threshold for phototherapy in infants guided by charts
What are some important causes of haemolysis in infants?
- ABO incompatibility
- Rhesus disease
- Bruising/cephalhematoma
- Red cell membrane defects (e.g. spherocytosis)
- Red cell enzyme defects (e.g. G6PD)
What are some important causes of haemolysis in infants?
- ABO incompatibility (Blood group, DCT)
- Rhesus disease (Blood group, DCT)
- Bruising/cephalhematoma (clinical exam)
- Red cell membrane defects (e.g. spherocytosis) (Blood film)
- Red cell enzyme defects (e.g. G6PD) (G6PD assay)
What can cause abnormal conjugation?
Gilbert’s disease-common, mild
Crigler-Najjar syndrome-v.rare, severe
(if suspected look at genotype/phenotype)
What assessments used to look for sepsis as a cause of unconjugated infant jaundice?
Urine + blood cultures, TORCH screen
What is prolonged infant jaundice?
Jaundice persisting beyond 2 weeks of life (3 weeks for preterm infants)
Causes:
- Anatomical (biliary obstruction)-conjugated
- Neonatal hepatitis-conjugated
- Hypothyroidism (UNconjugated)
- Breast milk jaundice (UNconjugated)
Conjugated jaundice in infants is … and always requires further testing
ALWAYS ABNORMAL
What is the most important test in prolonged jaundice?
Split bilirubin
What can cause biliary obstruction and therefore prolonged jaundice?
- Biliary atresia-conjugated jaundice, pale stools
- Choledochal cyst-conjugated jaundice, pale stools
ALWAYS assess stool colour in infants with prolonged jaundice
- Alagille syndrome - intrahepatic cholestasis, dysmorphism, congenital cardiac disease
What is biliary atresia and what does it present as?
Congenital fibro inflam disease of bile ducts that leads to destruction of extra-hepatic bile ducts
Presents with prolonged, conjugated jaundice
Pale stools, dark urine
Progression to liver failure if not identified or treated - treatment promptly determines prognosis
Most common indication for liver transplantation in children
What is the treatment for biliary atresia?
Kasai portoenterostomy
- Success rate diminishes rapidly with age
- Best results if performed before 60 days (<9weeks)
Assessment of prolonged infant jaundice is primarily targeted at what?
Diagnosing patients with biliary atresia early
Investigations done for the causes of prolonged jaundice -biliary obstruction?
- Split bilirubin
- Stool culture
- USS
- Liver biopsy
- Dysmorphism
- Genotype
Prolonged especially conjugated jaundice and know they don’t have biliary atresia what should be thought about?
NEONATAL HEPATITIS
-A1AT deficiency
- Galactosaemia
- Glycogen storage disorders
- Hypothryoidism
