Jaundice

Question 1

Jaundice - overview

Answer 1

1. Occurs when SBR >25-20mmol/L
2. Rare outside neonatal period
3. First determine the SBR and conjugated (direct) fraction
4. Unconjugated jaundice is rarely due to liver disease
5. Conjugated jaundice (>20mmol/L) is due to liver disease and requires investigation

Question 2

Unconjugated jaundice - causes

Answer 2

Due to excess bilirubin production, impaired liver uptake or conjugation

Haemolysis

1. Spherocytosis
2. G6PD deficiency
3. Sickle cell anaemia
4. Thalassemia

Defective bilirubin conjugation
5. Gilbert syndrome, or Grigler-Najjar syndrome

Question 3

Intrahepatic cholestasis - causes

Answer 3

Due to hepatocyte damage +/- cholestasis. There is unconjugated +/- conjugated hyperbilirubinaemia

1. Infectious (3)
   - Viral hepatitis
   - Bacterial hepatitis
   - Toxoplasma gondii
2. Toxic (1)
   - Drugs/poisons (e.g. paracetamol OD, sodium valproate, anti-TB drugs, cytotoxic drugs)
3. Metabolic - (5)
   - Galactosaemia, hereditary fructose intolerance
   - Tyrosinaemia
   - Wilson’s disease
   - a1-antitrypsin deficiency
   - Hypothyroidism
4. Cardiovascular
   - Budd-Chiari syndrome
   (- RHF?)
5. Other
   - Alagille syndrome
   - Autoimmune hepatitis

Question 4

Cholestatic (obstructive) jaundice - causes

Answer 4

Due to bile duct obstruction

1. Biliary atresia
2. Choledochal cyst
   ___
3. Caroli’s disease
4. Cholelithiasis, cholecystitis
5. Cystic fibrosis; obstructive tumours or cysts

Question 5

Jaundice - ix

Answer 5

1. Bloods - 1 (5) = FBE, blood film, reticulocyte count, coagulation studies, blood cultures (if indicated)
2. Bloods - 2 (5) = UEC, SBR, LFTs, BGL, TFTs
3. Other (5) = viral serology, IEM (inborn errors of metabolism) screen, copper studies, a1-antitrypsin level, immunoglobulins (ANA, smooth muscle and liver/kidney antibodies)
4. Imaging (3) = Abdominal U/S, abdominal CT/MRI, biliary scintigraphy (e.g. hepatoiminodiacetic acid [HIDA] scan)
5. Liver biopsy (when?)

Question 6

Jaundice - mx

Answer 6

1. Remove or tx underlying cause
2. Correct BGL if low and correct clotting abnormalities
3. Phototherapy may be helpful if jaundice has a significant unconjugated component (e.g. Grigler-Najjar syndrome)
4. Tx associated anaemia if due to haemolysis
5. Tx liver failure as appropriate