Approach to the yellow baby Flashcards
(34 cards)
Which enzyme is notably elevated in hepatocellular damage?
Alanine aminotransferase (ALT) Aspartate aminotransferase (AST)
Which enzymes are elevated in biliary disease?
Alkaline phosphatase
Gamma glutamyl transferase (GGT)
What are some tests to assess liver function?
Coagulation Albumin Bilirubin BG Ammonia
How do we test coagulation?
Prothrombin time
APTT
How might jaundice present?
Incidental finding on abnormal blood test
Symptoms/signs of chronic liver disease
What are some signs of chronic liver disease in children?
Growth failure Encephalopathy Portal hypertension Varices Splenomegaly Ascites Hypotonia Clubbing Hepatorenal failure Epistaxis Bruising and petechiae Muscle wasting
How is chronic liver disease related to Rickets?
Rickets may occur secondary to VitD deficiency
Is unconjugated bilirubin water soluble?
No
Is conjugated bilirubin water soluble?
Yes
How is unconjugated formed?
Post-mature erythrocytes broken down to haem
Haem to biliverdin
Biliverdin reductase breaks it down to unconjugated bilirubin
How does bilirubin become conjugated?
Binds to albumin to be transported to liver
Glucuronic acid added by glucuronyl transferase
This forms conjugated bilirubin
How is conjugated bilirubin excreted?
Excreted through bile into intestine
De-conjugated by β-glucuronidase
Reabsorbed into enterohepatic circulation to be excreted in stool
Where is the problem in pre-hepatic jaundice?
Conversion of post-mature erythrocytes to unconjugated bilirubin
Mostly results in unconjugated bilirubin
Where is the problem in intrahepatic jaundice?
Conjugation of bilirubin in the liver
Result is mixture of unconjugated and conjugated bilirubin in the liver
Where is the problem in post-hepatic jaundice?
Excretion of conjugated bilirubin
Result is mostly conjugated bilirubin
Is jaundice in a neonate always pathological?
Yes
What are the usual causes of jaundice in a neonate?
Haemolysis
Sepsis
What are the usual causes for a 0-14 day old baby?
Physiological
Breast milk
Sepsis
Haemolysis
What are the usual causes of jaundice in a baby >2 weeks?
Extrahepatic obstruction
Neonatal hepatitis
Hypothyroidism
Breast milk
What kind of bilirubin predominates in physiological jaundice?
Unconjugated
What is physiological jaundice?
Shorter RBC life span in infants (80-90 days)
Relative polycythaemia
Relative immaturity of liver function
Develops after first day of life
What are some likely causes of breast milk jaundice?
Inhibition of UDP by progesterone metabolite
Increased enterohepatic circulation
What kind of bilirubin predominates in breast-milk jaundice?
Unconjugated
How is kernicterus caused?
Unconjugated bilirubin crosses BBB
Neurotoxic and deposits in brain
