Jaundice

Question 1

what are the three classifications of jaundice?

Answer 1

• pre-hepatic
• intrahepatic
• post-/extra-hepatic

Question 2

what is pre-hepatic jaundice?

Answer 2

• occurs when bilirubin metabolism is affected before it reaches the liver, resulting in unconjugated hyperbilirubinemia
• it is typically caused by increased red cell haemolysis, which produces excess unconjugated bilirubin

Question 3

how does haemolytic anaemia contribute to increased bilirubin levels?

Answer 3

• increases bilirubin due to increased haemolysis of red blood cells
• haemolysis can occur intravascularly or extravascularly (where phagocytes remove defective or antibody-coated red cells)

Question 4

what are the genetic causes of haemolytic anaemia?

Answer 4

• red cell membrane defects (e.g. hereditary spherocytosis)
• haemoglobin abnormalities (e.g. sickle cell anaemia, thalassaemia)
• enzyme deficiencies (e.g. G6PD deficiency, pyruvate kinase deficiency)

Question 5

what are the causes of acquired haemolytic anaemias?

Answer 5

acquired haemolytic anaemias are often immune-mediated and can be:

• isoimmune (e.g. blood transfusion reaction)
• autoimmune (e.g. SLE, lymphoma, leukaemia, drug-related)

Question 6

what are non-immune causes of acquired haemolytic anaemia?

Answer 6

• disseminated intravascular coagulation (DIC)
• haemolytic uraemic syndrome (HUS)
• thrombotic thrombocytopenia
• hypersplenism
• cirrhosis

Question 7

what is gilbert’s syndrome?

Answer 7

a benign genetic condition where bilirubin is not transported into bile at the usual rate, causing intermittent jaundice due to unconjugated hyperbilirubinaemia

Question 8

what is crigler-najjar syndrome?

Answer 8

• a rare autosomal recessive disorder where deficiency of diphosphate glucuronosyltransferase impairs bilirubin conjugation and excretion, leading to unconjugated hyperbilirubinaemia
• it typically presents in neonates

Question 9

what is intrahepatic jaundice?

Answer 9

occurs when hepatocyte damage reduces bilirubin conjugation or causes cholestasis

Question 10

what are the three clinical phases of viral hepatitis?

Answer 10

1. prodromal
2. icteric
3. convalescent

Question 11

what is alcoholic hepatitis?

Answer 11

• occurs when the liver metabolises alcohol, producing acetaldehyde as a by-product
• this binds to proteins in liver cells, causing hepatocyte injury

Question 12

what is decompensated cirrhosis?

Answer 12

• irreversible scarring of the liver with abnormal nodules
• symptoms of liver failure only become apparent when 80-90% of hepatic tissue is damaged
• it causes portal hypertension due to distortion of intrahepatic vasculature by fibrosis

Question 13

what can trigger decompensation in a patient with cirrhosis?

Answer 13

• infection (e.g. SBP)
• bleeding (e.g. variceal bleeding)
• alcohol binge

Question 14

what is primary biliary cholangitis (PBC)?

Answer 14

• a slowly progressive autoimmune disease that destroys small interlobular bile ducts, causing intrahepatic cholestasis
• this leads to hepatocyte damage, and fibrosis + can eventually progress to cirrhosis

Question 15

what causes extra-hepatic jaundice?

Answer 15

occurs due to extra-hepatic cholestasis, often caused by:

• intraluminal structural abnormalities (e.g. strictures)
• extrinsic compression (e.g. tumours or gallstones)

Question 16

how can malignancies cause bile duct obstruction?

Answer 16

• intraluminal obstruction (e.g. inside the common bile duct or gallbladder)
• extrinsic compression (e.g. pancreatic cancer)

Question 17

what are the key features of cholangiocarcinoma in relation to jaundice?

Answer 17

• cancer of the gallbladder or bile duct that causes intraluminal obstruction of bile flow
• it often presents late with jaundice, RUQ pain + weight loss

Question 18

What are the key features of pancreatic cancer in relation to jaundice?

Answer 18

• cancer of the head of the pancreas can cause extrinsic compression of the biliary tree, blocking bile flow
• it typically presents late with jaundice, weight loss + abdominal pain

Question 19

how can pancreatitis cause jaundice?

Answer 19

• pancreatitis is inflammation of the pancreas, which presents with severe epigastric pain + vomiting
• jaundice can occur due to a common bile duct stone, excess alcohol use, or extrinsic compression of the common bile duct from pancreatic inflammation and swelling

Question 20

what blood tests are used to investigate suspected pre-hepatic jaundice or haemolytic anaemia?

Answer 20

• haptoglobin (e.g. binds free Hb): ↓ in haemolytic anaemia
• lactate dehydrogenase (LDH): ↑ due to increased haemolysis
• blood film: identifies red cell abnormalities or haematological malignancy
• split bilirubin test: measures conjugated/unconjugated bilirubin — ↑ unconjugated bilirubin indicates pre-hepatic jaundice

Question 21

what do LFTs show in hepatocellular jaundice?

Answer 21

• ↑ AST & ALT
• AST:ALT > 2:1 - ArLD
• ↑ GGT - EtOH

Question 22

how is ascitic fluid analysed?

Answer 22

ascitic fluid is collected by ascitic aspiration + sent for:

• M, C & S
• gram staining is used to identify any organisms initially + count numbers of white cells

Question 23

what does a raised white cell count in ascitic fluid indicate?

Answer 23

> 250/µL ( ↑ polymorphic) - SBP
250/µL ( ↑ lymphocytic) - TB

Question 24

how is alcohol cessation supported in patients with liver disease?

Answer 24

• benzodiazepines (e.g. lorazepam, chlordiazepoxide)
• vitamin replacement with intravenous thiamine/B12 (Pabrinex)

Question 25

when is ursodeoxycholic acid used?

Answer 25

it helps prevent the formation of gallstones by reducing bile acid production

Question 26

how is pruritis caused by jaundice managed?

Answer 26

colestyramine is a bile acid sequestrant that prevents the reabsorption of bile acids, helping reduce itching in obstruction of the biliary tree (e.g. PBC)