Jaundice

Question 1

What is Jaundice?

Answer 1

The clinical manifestation of elevated plasma levels of bilirubin presenting with yellow tinged skin and sclera

Question 2

What is bilirubin?

Answer 2

Metabolic breakdown product of haemoglobin (RBCs))

Question 3

Where does bilirubin metabolism/Hb metbolism begin?

Answer 3

Spleen

Question 4

Describe the process of bilirubin metabolism:

Answer 4

RBC goes to spleen
Hb broken down into Haem and Globin
Haem further broken down into Biliverdin
Biliverdin converted into UNCONJUGATED bilirubin
This travels to the liver to be conjugated

Conjugated bilirubin oxidised to stercobilin in the duodenum
Conjugated bilirubin becomes urobilinogen in the kidneys

Question 5

What does stercobilin contribute to the faeces?

Answer 5

The brown pigment

Question 6

What gives the yellow colour in the urine?

Answer 6

The breakdown product of urobilinogen urobilin

Question 7

What plasma protein carries unconjugated bilirubin to the liver for conjugation?

Answer 7

Albumin

Question 8

What amino acid is uncojugated bilirubin conjugated with making it water soluble for excretion?

Answer 8

Glucuronic acid

Question 9

What are the 3 different types of Jaundice?

Answer 9

Pre-hepatic jaundice
Hepatic jaundice
Post-hepatic jaundice

Question 10

What is Pre-hepatic jaundice?

Answer 10

Also called haemolytic jaundice

It’s when theres an increased amount of Hb being broken down (haemolysis)

Question 11

What is the mechanism by which pre-hepatic jaundice causes jaundice?

What type of bilirubin levels are elevated as a result?

Answer 11

Inc haemolysis or RBCs
Overwhelms livers ability to conjugate bilirubin

INC levels of UNCONJUGATED bilirubin in bloodstream

Livers function is still perfectly intact (can still conjugate) its just overwhelmed by too much bilirubin

Question 12

What can cause Pre-hepatic jaundice?

Answer 12

-Haemolytic anaemias (sickle cell anemia, thalassemia)
-Hereditary conditions affecting RBC strucutre/function (hereditary Spherocytosis)
-meds or toxins causing haemolysis
-infections (malaria)
-blood transfusion reactions

Question 13

What is the key indicator that a patient has a pre-hepatic jaundice?

Answer 13

Elevated levels of UNCONJUGATED Bilirubin in blood

Question 14

What is hepatic jaundice?

Answer 14

When the jaundice is caused by reduced hepatic function

Leads to reduced ability to conjugate bilirubin

Question 15

What can cause Hepatic Jaundice?

Answer 15

Acute and chronic liver diseases

Acute viral hepatitis
Paracetamol toxicity
Certain infections affecting liver
Chronic liver diseases such as cirrhosis

Question 16

What is the key indicator that a patient has hepatic jaundice?

Answer 16

Elevated levels of CONJUGATED and UNCONJUGATED bilirubin

Question 17

What is Post-hepatic jaundice?

Answer 17

/obstructive jaundice when theres an obstruction in the bile ducts preventing normal flow of bile from liver to intestines

Question 18

What levels of bilirubin are high in the blood with post-hepatic jaundice?

Answer 18

CONJUGATED bilirubin

Blockage happens after the liver

Question 19

What can cause post-hepatic jaundice?

Answer 19

Gallstones
Inflammation or scarring of bile ducts (primary sclerosing cholangitis)
Pancreatic tumours compressing biliary tree
Biliary atresia

Question 20

What are the key presentations of a patient with post-hepatic jaundice?

Answer 20

Elevated CONJUGATED BILIRUBIN

Pale faeces and Dark Urine

Abdominal pain if gallstones cause

Question 21

Why are the faces pale and the urine dark in post-hepatic jaundice?

Answer 21

Levels of conjugatde bilirubin are high
They are unable to progress through the biliary tree into the small intestine so the conjugated bilirubin is absorbed back in the blood where it gets filtered by the kidney so levels of conjugated bilirubin are high in the urine

Question 22

Why is a painless post hepatic jaundice worrying?

Answer 22

Could be pancreatic carcinoma compressing duct

Question 23

How can cirrhosis cause post-hepatic jaundice?

Answer 23

Non expansive liver causes portal hypertension
This can compress bileduct