Jaundice

Question 1

What is jaundice?

Answer 1

Accumulation of bilirubin in the skin

Question 2

What is bilirubin?

Answer 2

Breakdown product of haem

Question 3

What is the clinical presentation of jaundice?

Answer 3

Yellow/orange tinge to skin and the sclera of the eyes.

Itch - bilirubin irritates nerve endings

Question 4

What are the two forms bilirubin can be in?

Answer 4

Conjugated and non-conjugated

Question 5

How does non-conjugated bilirubin become conjugated? What does this allow?

Answer 5

Conjugated bilirubin is bound to another molecule.

This allows it to be excreted from the body.

Question 6

Why can non-conjugated bilirubin not be excreted from the body?

Answer 6

It isn’t water soluble

Question 7

What is stool and urine colour dependant on?

Answer 7

Bilirubin conjugation

Question 8

Where is bilirubin conjugated?

Answer 8

In the endoplasmic reticulum of hepatocytes

Question 9

What are the 3 classifications of jaundice?

Answer 9

Prehepatic

Hepatic

Post hepatic

Question 10

What causes pre hepatic jaundice?

Answer 10

Accumulation of bilirubin due to excessive RBC breakdown;

Haemolytic anaemia
Post-transfusion
Neonataal mixing
Gilberts syndrome

Question 11

How does haemolytic anaemia cause pre hepatic jaundice?

Answer 11

RBC’s are broken down quicker than they are produced = accumulation of bilirubin

Due to the increased levels - some of the bilirubin bypasses the hepatocyte uptake and unconjugated bilirubin remains in the blood.

Question 12

How does a blood transfusion cause pre hepatic jaundice?

Answer 12

If there is an inaccurate blood match the immune system will attack the RBC and cause them to be broken down releasing bilirubin.

Question 13

How does neonatal mixing cause pre hepatic jaundice?

Answer 13

Mother and baby’s blood mix during birth - baby’s immune system targets the mothers RBC causing them to be broken down = bilirubin release.

Question 14

What is the consequences of neonatal mixing?

Answer 14

Accumulation of bilirubin can lead to Kernicterus - brain damage and damage to nerve fibres.

This can be permanent.

Question 15

How is neonatal jaundice treated?

Answer 15

Phototherapy - baby placed under a blue light which breaks down bilirubin in the skin.

Question 16

How does Gilbert’s disease cause pre hepatic jaundice?

Answer 16

There is a decreased bilirubin uptake by the hepatocytes - unconjugated bilirubin remains in the blood.

Question 17

What are the hepatic causes of jaundice?

Answer 17

Prevents metabolism of harm breakdown products

Cirrhosis
Drug induced
Impaired enzyme action
Secretory failure

Question 18

How does cirrhosis cause hepatic jaundice?

Answer 18

There is a reduction in hepatocytes and same levels of bilirubin = an accumulation

Question 19

How does impaired enzyme activity cause hepatic jaundice?

Answer 19

Unconjugated bilirubin cannot be conjugated since hepatocytes are non-functioning due to disease.

Question 20

How does secretory failure cause hepatic jaundice?

Answer 20

non-conjugated bilirubin is taken up by the hepatocytes and conjugated yet cannot leave the hepatocyte due to the membrane becoming impermeable.

Question 21

What are the post-hepatic causes of jaundice?

Answer 21

Bile outflow blockage

Intrahepatic
Primary biliary sclerosis

Extrahepatic
Gallstones
Carcinoma of the head of the pancreas
Cholangiocarcinoma

Question 22

What occurs in post-hepatic jaundice?

Answer 22

Unconjugated bilirubin enters the hepatocytes is conjugated and passes out of the hepatocyte via the bile canaliculus.

The conjugated bilirubin then encounters a blockage and is forced back up into the hepatocyte and into the blood

Question 23

How does primary biliary sclerosis cause post hepatic intrahepatic jaundice?

Answer 23

Immune system attacks the bile duct causing scarring and narrowing/obstruction.

Question 24

How do gallstones cause post hepatic extrahepatic jaundice?

Answer 24

Gallstones move out of the gallbladder and into the biliary tree where they can cause blockages.

Question 25

How does pancreatic cancer cause post hepatic extrahepatic jaundice?

Answer 25

Pancreatic tumours commonly occur at the head of the pancreas.
Common bile duct lies near the head of the pancreas so as the tumour grows it blocks the bile duct and obstructs outflow of conjugated bilirubin

Question 26

How do cholangiocarcinomas cause post hepatic extrahepatic jaundice?

Answer 26

Tumour of the bile duct so causes blockage of the bile duct as it grows

Question 27

What are the clinical features of pre-hepatic jaundice?

Answer 27

Dark stool and dark urine

Question 28

What are the clinical features of hepatic jaundice?

Answer 28

Pale stool and pale urine

Question 29

What are the clinical features of post-hepatic jaundice?

Answer 29

Pale stool and dark urine

Question 30

What are the symptoms of gallstones? When do they occur?

Answer 30

Pain on shoulder tip
Abdominal pain on the right side

Pain occurs when eating fatty foods.
Fat triggers the contraction of the gallbladder to release bile which emulsifies fat.

Question 31

How do you investigate/image the jaundiced patient?

Answer 31

Ultrasound

Radiographs (however not all gallstones are radiopaque)

Endoscopic retrograde cholangiopancreatography
Dye injected into the biliary tree to highlight obstructions.

Question 32

What are the functions of an endoscopic retrograde cholangiopancreatography?

Answer 32

Injects die to highlight blockages;

Places a stent (when bile ducts compresses by tumour)
Can make an incision to free the gallstones

Question 33

How do you treat post-hepatic jaundice?

Answer 33

Remove the obstruction:
ERCP:
Stent (tumour)
Incision (gallstones)

Lithotripsy - sonic waves to destroy gallstones.

Question 34

How do you prevent gallstones?

Answer 34

Remove gallbladder

Prevent the accumulation of bile via low calorie / low cholesterol diet.

Reduce the amount of bile resorption by the GIT via colestyramine drug.