The Yellow Baby Flashcards
Function of the liver
Produces Essential proteins - albumin - clotting factors Absorption and metabolism of food - fat - carbohydrate Storage - glycogen - other substrates and minerals Metabolism and excretion of toxins
LFTs
Bilirubin - Total - Split ALT / AST Alkaline phosphatase GGT
What is “split bilirubin”?
Direct (conjugated) and indirect (unconjugated)
What does bilirubin indicate?
How well you liver is clearing bile
What are ALT / AST elevated in?
Hepatocellular damage (hepatitis) Other processes e.g. muscle diseases
What are ALT / AST?
Transaminases
When is alkaline phosphatase elevated?
Biliary disease
Which LFT is usually ignored in children and why?
Alkaline phosphate
Because it is affected by bone growth and so can fluctuate and be high but nothing to do with their liver at al
When is GGT elevated?
Biliary disease
What does GGT stand for?
Gamma glutamyl transferase
Tests to assess liver function
Coagulation - prothrombin time PT/INR - APTT Albumin Bilirubin Blood glucose Ammonia
Presentation of paediatric liver disease
JAUNDICE abnormal incidental finding on blood test Chronic ; Encephalopathy Epistaxis Spider naevi Varices with portal HTN muscle wasting from malnutrition bruising and petechiae splenomegaly with portal HTN Hypersplenism Hepatorenal failure Liver palms Clubbing Loss of fat stores secondary to malnutrition Hypotonia Ascites Peripheral neuropathy
What is jaundice?
A yellow discolouration of skin and tissues due to accumulation of bilirubin
Where Is jaundice usually most obvious?
Sclera
At what level is bilirubin usually visible?
> 40 - 50 umol/l
Bilirubin metabolism
- Break down of RBCs into biliverdin
- Converted into unconjugated bilirubin by biliverdin reductase of tissues which happens all over the body
- Bilirubin goes to the liver and is converted to conjugated bilirubin - which goes to bile and gallbladder and is converted in small intestine into urobillogen
- either excreted by kidneys or going in stercobilin and is excreted into stool
What does stercobilin do?
Makes faeces the colour they are
Solubility of unconjugated bilirubin
Water insoluble
Fat soluble
Features of unconjugated bilirubin
Cant be directly excreted into kidneys or stool
What is neonatal jaundice classified by?
Age
What class of neonatal jaundice is ALWAYS pathological?
Early ( < 24 hrs old)
Causes of early ( <24 hours old) jaundice
Haemolysis
Sepsis
How old is intermediate neonatal jaundice?
24 hours - 2 weeks
Causes of intermediate neonatal jaundice
Physiological Breast milk Sepsis Haemolysis Abnormal conjugation of bilirubin
How long is prolonged neonatal jaundice?
> 2 weeks old
3 weeks for pre term infants
Causes of prolonged neonatal jaundice
Extrahepatic obstruction
Neonatal hepatitis
Hypothyroidism
Breast milk
Why do infants get neonatal jaundice?
Shorter RBC life span in infants (80-90 days)
Relative polycythaemia (180-200)
So loads of unconjugated bilirubin is produced
Relative immaturity of liver function
When does physiological jaundice occur?
AFTER the first day of life
What type of jaundice is physiological jaundice?
Unconjugated jaundice
What type of jaundice Is breast milk jaundice?
Unconjugated jaundice
How long can breast milk jaundice persist for?
up to 12 weeks
Why does sepsis cause jaundice?
Increases haemolysis
Slows down liver function
Causes of haemolysis causing jaundice in the neonate
ABO incompatibility - excessive haemolysis Rheus disease - excessive haemolysis Bruising / cephallhaematoma from birth trauma - excess of bilirubin production Red cell membrane defects e.g. spherocytosis - excessive haemolysis Red cell enzyme defects e.g. G6PD - excesshaemolysis
What causes abnormal conjugation of bilirubin?
Gilberts Disease
Criler-Najjar syndrome
What is kernicterus a complication of?
Neonatal unconjugated jaundice
Pathology of kernicterus
Unconjugated bilirubin is fat soluble and so can cross the BBB
Neurotoxic and deposits in brain
- especially basal ganglia
Presentation of kernicterus
Early signs - encephalopathy - poor feeding - lethargy - seizures Late consequences - severe choreathetoid CP - LDs - sensorineural deafness
Which type of bilirubin can cross the BBB?
Unconjugated
Treatment of neonatal jaundice
Phototherapy
What type of jaundice does phototherapy treat?
Unconjugated
What does phototherapy do?
Visible light (NOT UV) converts unconjugated bilirubin to water soluble isomer (photoisomerization)
What is exchange transfusion?
When phototherapy sometimes doesn’t bring it down efficiently, and have to do this more excessively, then may need a blood transfusion past this threshold
What type of jaundice always requires further investigations?
Prolonged
Causes of unconjugated prolonged neonatal jaundice
Hypothyroidism
Breast milk jaundice
Causes of conjugated prolonged neonatal jaundice
Anatomical (biliary obstruction) - Biliary atresia - choledochal cyst - alagille syndrome Neonatal hepatitis - viral hepatitis - parental nutrition - glycogen storage disorders - haemochromatosis - urea cycle defects
Presentation of biliary atresia causing neonatal jaundice
Conjugated jaundice
Pale stools
Investigations for biliary atresia
Split bilirubin
Stool colour
USS
Liver biopsy
What is a choledochal cyst?
Developmental condition where there is a cystic abnormality in bile ducts so get obstructive picture
What kind of jaundice is a cholechondral cyst?
Conjugated jaundice
What does a cholechondral cyst present with?
Pale stools
Jaundice
Investigations of a cholechondral cyst
Split bilirubin
Stool colour
USS
Pathology of Alagille syndrome
Congenital damage to intrahepatic bile ducts
Presentation of Alagille Syndrome
Intrahepatic cholestasis
Dysmorphism
Congenital heart disease
Investigations of alagille syndrome
Dysmorphism
Genotype
What type of jaundice in infants is ALWAYS abnormal?
Conjugated
What is the most important test in prolonged jaundice?
Split bilirubin
What should always be done along with split bilirubin as an investigation for prolonged jaundice in infants?
Pale stools In babies
What is biliary atresia?
Congenital fibro-inflammatory disease of bile ducts leading to destruction of extra-hepatic bile ducts
- so there is no flow of bile into small intestine out of the liver
Presentation of biliary atresia
Prolonged, conjugated jaundice
Pale stools
Dark urine
What can biliary atresia progress to if not identified and treated?
Liver failure
What is the most common indication for liver transplantation in children?
Biliary atresia
Treatment of biliary atresia
Kasai Portoenterostomy
