Jaundice

Question 1

Define biochemical hyperbilirubinaemia

Answer 1

more than the upper limit of normal for the biochemical reference range for bilirubin levels

Question 2

Define jaundice

Answer 2

clinical manifestation of hyperbilirubinaemia detected by a change of scleral and skin colour

Question 3

When is jaundice sclera/skin generally visible

Answer 3

biliribin >50 micromol/L

Question 4

What are howell-jolly bodies?

Answer 4

inclusions of nuclear chromatin remnants

Question 5

What are heinz bodies?

Answer 5

inclusions of denatured haemoglobin caused by oxidative damage

Question 6

What are siderocytes?

Answer 6

RBC containing granules of iron that are not part of the cell’s haemoglobin

Question 7

What are pappenheimer bodies?

Answer 7

inclusion bodies formed by phagosomes that have been engulfing excessive amounts of iron

Question 8

Solubility of unconjugated (indirect) bilirubin

Answer 8

insoluble
(binds to albumen and is carried in blood)

Question 9

Can indirect bilirubin appear in the urine?

Answer 9

no

Question 10

Solubility of conjugated bilirubin

Answer 10

water-soluble

Question 11

Can conjugated bilirubin appear in urine?

Answer 11

yes

Question 12

Types of jaundice

Answer 12

pre-hepatic
hepatic
post-hepatic

Question 13

Describe pre-hepatic jaundice

Answer 13

increase in blood unconjugated bilirubin (problem is with conjugation of bilirubin)
normal LFTs
no bilirubin in urine
no change in urine/faeces (NB haemoglobinuria in haemolysis)

Question 14

Pre-hepatic jaundice causes

Answer 14

increased RBC breakdown - too much bilirubin delivered to liver
large haematoma
failure of hepatic conjugation (due to genetics - Gilbert’s)

Question 15

Describe Gilbert’s syndrome

Answer 15

cause of pre-hepatic jaundice at times of stress
not harmful
no clinical problems
faulty function of UGT1

Question 16

Describe Crigler Najjar syndrome

Answer 16

absent or nearly absent UGT1A1 enzyme activity
prevents shortly after birth with kernicterus
phototherapy
liver transplant
causes build up of unconjugated bilirubin in blood

Question 17

What is kernicterus?

Answer 17

bilirubin-induced neurological damage

Question 18

What is breast milk jaundice?

Answer 18

cause of unconjugated hyperbilirubinaemia in healthy newborns who are primarily breastfed
discontinuation of breast feeding and using formula rapidly corrects hyperbilirubinaemia

Question 19

What is hepatic jaundice?

Answer 19

liver disease process affects the ability to both conjugate bilirubin and secrete the conjugated bilirubin into the biliary canaliculus

Question 20

Causes of hepatic jaundice

Answer 20

acute liver injury
acute liver failure
chronic liver disease - cholestatic disease (before cirrhosis)
when a patient with cirrhosis develops decompensation
acute en chronic liver failure

Question 21

Which type of bilirubin is high in hepatic jaundice?

Answer 21

mix of conjugated and unconjugated

Question 22

Urine/faeces of those with hepatic jaundice

Answer 22

patients will excrete conjugated bilirubin into the urine and conjugated bilirubin will not enter the bowel

dark urine
pale stools

Question 23

Clues that it might be hepatic jaundice

Answer 23

risk factors for liver disease
clinical signs of chronic liver disease
abnormal US - cirrhosis, ascites, portal hypertension, splenomegaly
other biochemical features of decompensated cirrhosis - prolonged PT, low albumen, low platelets

Question 24

Cause of post-hepatic jaundice

Answer 24

bile duct obstruction

Question 25

Complications of cholestasis

Answer 25

cosmetic
pruritis
fatigue/lethargy
increased energy requirements
vitamin ADEK
growth and hormonal disturbances
bone metabolism

Question 26

Features of post-hepatic jaundice

Answer 26

bilirubin is conjugated
excreted into biliary system
cannot move to bowel due to obstructed flow of bile out of biliary system
cholangiocytes become leaky and bilirubin leaks into blood
no conjugated bilirubin enters bowel

Question 27

Urine/faeces in post-hepatic jaundice

Answer 27

pale stools
dark urine (conjugated bilirubin enters urine)

Question 28

What causes pruritis in post-hepatic jaundice?

Answer 28

bile salts not excreted into the bowel

Question 29

Clues for post-hepatic jaundice

Answer 29

often due to cancers of bile duct or pancreas - weight loss + painless jaundice
raised AlkPhos + GGT
abnormal cross-sectional imaging - CT, MRI
painful obstructive jaundice - normally stone - US then MRCP
look for cholangitis