Jaundice

Question 1

Jaundice Etiology?

Answer 1

Caused by:
Hepatocellular disease, 
Biliary obstruction, 
Hemolytic anemia, 
Congenital hyperbilirubinemias

Question 2

Normal Physiology of Bilirubin Handling?

Answer 2

1. Heme derived from various catabolic processes
2. Intracellular derivation of bilirubin from heme
3. Bilirubin (in unconjugated state) is transported to liver for processing while bound to albumin (unconjugated bilirubin)
4. Intrahepatic conjugation of bilirubin
5. Excretion of conjugated bilirubin into bile canaliculi
6. Post-hepatic modification of bilirubin in GI Tract by intestinal bacteria into urobilin and then stercobilin (faeces)
7. urobilin reabsorbed and excreted in urine

Question 3

Only which derivative of bilirubin is soluble?

Answer 3

Only conjugated bilirubin is soluble and can be reabsorbed from the intestine.

Question 4

Prehepatic causes of jaundice?

Answer 4

1. Hemolytic anemias
2. Resorption of blood from large internal hemorrhages
3. Ineffective erythropoiesis

Question 5

Hepatic (hepatocellular) causes of jaundice?

Answer 5

1. Widespread hepatocellular diseases (hepatitis, cirrhosis)
2. Physiologic jaundice of the newborn
3. Gilbert syndrome
4. Crigler-Najjar syndrome type 1 and 2

Question 6

Posthepatic (obstructive) causes of jaundice?

Answer 6

1. Gallstones
2. Carcinomas of head of pancreas,
3. Bile duct carcinoma
4. Tumours of ampulla of Vater
5. Extrahepatic biliary atresia

Question 7

Predominantly unconjugated hyperbilirubinemia CAUSES?

Answer 7

Prehepatic & some hepatic causes of

hyperbilirubinemia (those affecting uptake & conjugation of bilirubin)

Question 8

Predominantly unconjugated hyperbilirubinemia OUTCOME?

Answer 8

􀂃 Unconjugated bilirubin is insoluble in water, hence complexed to albumin in blood

􀂃 Cannot be excreted in urine (not filtered when albumin-bound)

􀂃 Can cross blood-brain-barrier, causing kernicterus (severe neurologic damage) in young children

Question 9

Predominantly conjugated hyperbilirubinemia CAUSES?

Answer 9

Posthepatic & some hepatic causes of

hyperbilirubinemia (those affecting excretion of bilirubin)

Question 10

Predominantly conjugated hyperbilirubinemia OUTCOME?

Answer 10

􀂃 Conjugated bilirubin in water-soluble, only loosely bound to albumin in blood

􀂃 Excreted in urine

􀂃 Cannot cross blood-brain-barrier

Question 11

Jaundice clinical signs?

Answer 11

yellow discoloration of:
skin,
sclera,
tissues,

pre= unconjugated br, normal urine, dark stools
hepatic= conjugated/unconjugated br, tea colored urine, normal stools
post= conjugated br, dark urine, pale stools

Question 12

Prehepatic Jaundice lab findings?

Answer 12

absent urine bilirubin (acholuria),

increased urine urobilinogen

Question 13

Hepatic Jaundice lab findings?

Answer 13

increased urine bilirubin,
normal or decreased urine urobilinogen, increased ALT and AST,
increased ALP

Question 14

Posthepatic Jaundice lab findings?

Answer 14

increased urine bilirubin,
decreased urine urobilinogen,
increased ALP,
hypercholesterolemia

Question 15

Jaundice treatment?

Answer 15

Treat underlying cause