Liver Flashcards
What are examples of LFTs?
Bilirubin
ALT/AST
Alkaline phosphatase
Gamma glutamyl transferase
What causes elevated ALT/AST?
Hepatitis
What causes elevated ALP and GGT?
Biliary disease
What tests can be used to assess liver function?
Coagulation - prothrombin time, INR, APTT
Albumin
Bilirubin
What is the most common manifestation of liver disease in children?
Jaundice
Where is jaundice most obvious?
Sclera
What level of bilirubin causes visible jaundice?
> 40-50umol/l
How is bilirubin metabolised?
Post mature erythrocytes are broke down releasing unconjugated bilirubin
Bilirubin transported to liver via albumin and conjugated
Conjugated bilirubin is stuck into bile
What are causes of jaundice in the first 24 hours of life?
Always pathological - haemolysis, sepsis
What are causes of jaundice from 24 hours of age to 2 weeks of age?
Physiological
Breast milk
Sepsis
Haemolysis
What are causes of jaundice lasting over 2 weeks?
Extrahepatic obstruction
Neonatal hepatitis
Hypothyroidism
Breast milk
What causes physiological jaundice?
High levels of HbF which has a shorter life span
Relative polycythaemia
Relative immaturity of liver function prevents conjugation of bilirubin
Leads to unconjugated jaundice after first day of life
What is breast milk jaundice?
Breast fed babies jaundice lasts longer
What happens if unconjugated jaundice isn’t prevented?
Kernicterus
What is kernicterus?
Unconjugated jaundice can pass the blood brain barrier so toxic deposits in brain
How is unconjugated jaundice treated?
Phototherapy - converts photoisomerization of bilirubin to water soluble form
What wavelength is used for phototherapy?
450 nanometres
What are causes of haeomolysis?
ABO incompatibility Rhesus disease Bruising/cephalhaematoma Red cell membrane defects Red cell enzyme defects
What are causes of abnormal bilirubin conjugation?
Gilbert’s disease
Crigler-Naijar syndrome
When is jaundice considered prolonged?
Jaundice beyond 2 weeks of life
Beyond 3 weeks in preterms
What are causes of prolonged jaundice?
Biliary obstruction
Neonatal hepatitis
Hypothyroidism
Breast milk jaundice
Is there a normal cause of conjugated jaundice in infants?
No - any infant with conjugated jaundice requires investigation
What is the most important test in prolonged jaundice?
Split bilirubin
In babies with prolonged jaundice what should be examined in stool?
Colour
What is biliary atresia?
Congenital fibro-inflammatory disease of bile ducts leading to destruction of extra hepatic bile ducts
What are features of biliary atresia?
Prolonged conjugated jaundice
Pale stools, dark urine
Progression to liver failure if not identified and treated
What is the primary treatment for biliary atresia?
Kasai procedure - surgical (Kasai portoenterostomy)
What is the main reason to assess children with prolonged jaundice?
Diagnosing patients with biliary atresia early
When is Kasai procedure mot likely to succeed?
<60 days
Chance of success rapidly drops after this point
What investigations should be done in prolonged conjugated jaundice?
Split bilirubin
Stool colour
Ultrasound
Liver biopsy
What are causes of neonatal hepatitis?
Alpha-1-antitrypsin deficiency Galactosaemia Tyrosinaemia Urea cycle defects Hypothyroid Viral hepatitis
