Jaundice

Question 1

Jaundice definition

Answer 1

Yellow discolouration of the tissues, noticed especially in the skin and sclera, due to accumulation of bilirubin. Detectable clinically when bilirunin levels >50umol/L (40)

Question 2

Physiology of Bilirubin metabolism

Answer 2

Physiology

• Unconjugated bilirubin formed mainly in spleen by the breakdown of haemoglobin
• It is soluble and is transported in the plasma bound to albumin
• Taken up by the liver by active transport, it is converted in the hepatocytes into conjugated bilirubin (water-soluble)
• It is excreted into the bile canaliculi and via the main bile ducts into the DD
• Ten percent of the unconjugated bilirubin is reduced to urobilinogen by small intestinal bacteria, reabsorbed in the terminal ileum, and then excreted in the urine (enterohepatic circulation)
• Ninety percent is converted by colonic bacteria to stercobilinogen which is excreted in faeces

Question 3

Causes of jaundice

Answer 3

• Pre hepatic (Haemolytic jaundice) – unconjugated hyperbilirubinaemia
• Hepatic (Hepatocellular jaundice) – conjugated or unconjugated hyperbilirubinaemia
• Post hepatic (Cholestatic (obstructive) jaundice- conjugated hyperbilirubinaemia

Question 4

Pre-hepatic causes

Answer 4

Pre-hepatic

• Congenital abnormalities of red cell structure or content (e.g hereditary spherocytosis, sickle cell)
• Autoimmune haemolytic anaemia
• Transfusion reactions
• Drug toxicity

Question 5

Hepatic causes

Answer 5

Hepatic Jaundice

• Hepatic unconjugated hyperbilirubinaemia
  
  • Gilberts syndrome (deficiency or abnormalities of unconjugated bilirubin uptake)
  • Crigler-najjar syndrome – abnormality of conjugation process enzymes
• Hepatic conjugated hyperbilirubinaemia
  
  • Infection – Viral (e.g hep A,B,C,EBV, CMV), bacterial (liver abscess, leptospirosis), parasitic( amoebic)
  • Drugs e.g paracetamol overdose
  • Non infective hepatitis

Question 6

Post hepatic causes

Answer 6

Intraluminal abnormalities of bile ducts

• Gallstones
• Blood clot
• Parasites

Mural abnormalities of bile ducts

• Cholangiocarcinoma
• Congenital atresia
• Sclerosing cholangitis
• Biliary cirrhosis

Extrinsic compression of bile ducts

• Pancreatitis
• Tumours (head of pancreas)
• Lymphadenopathy of porta hepatitis nodes

Question 7

History

Answer 7

• FH of blood disorders/transfusions
• Recent foreign travel and work (exposure to infectious agents)
• Recent drugs or changes in medications
• Recent surgery or anaesthesia
• History of gall stones
• Alcohol intake, cholangitis (pain, fever, rigors) and carcinoma
• Alcohol and IV drug use

Question 8

Examination of jaundice

Answer 8

• Signs of CLD (spider naevi, palmar erythema, leukonychia, clubbing, gynaecomastia_
• Hepatic encephalopathy
• Lymphadenopathy
• Hepatosplenomegaly
• Splenomegaly
• Ascites and palpable gallbladder (cholestatic)
• Pale stools
• Dark urine

Question 9

Investigations

Answer 9

• Haematology – FBC, clotting (increased protrhombin),Reticulocytosis, abnormal blood film
• Chemistry- U and Es, LFT, ALT, AST, Alk Phosp, y-gt, total protein
• Microbiology- blood and other cultures (leptospiral, and hepatitis A,B,C serology)
• Immunology (Anti-smooth muscle antiboides), Anti-mitochondrial antibodies (PBC)
• Urine – Bilirubin is absent in pre-hepatic, in obstructive jaundice, urobilinogen is absent
• Utralsound – are the bile ducts dilated >6mm, Are there gall stones, hepatic metastses or a pancreatic mass
• ERCP – if the bile ducts are dilated and LFTs not improving
• MRCP- if conventional ultrasound shows gallstone but no definite common bile duct stones
• Liver biopsy- if bile ducts normal
• CT/MRI if abdomonal malignancy is suspected

Question 10

Treatment of jaundice

Answer 10

• Treat the cause promptly
• Haemolytic jaundice
  
  • Steroids for autoimmune case
  • Splenectomy (laproscopic)
• Obstructive jaundice
  
  • ERCP and PTC may be used as above for stones, strictures
  • Surgical drainage used for failed interventional treatments
  • Surgical resection- whipples pancreaticduodenectomy
• Hepatocellular jaundice
  
  • Remove causative agent
  • Transplant in specific cases

Question 11

Complications of jaundice

Answer 11

• Renal failure (hepatorenal failure) – combination of infection, dehydration and a direct effect of high levels of bilirubin and other toxic products
• Biliary infection (cholangitis) – obstructive jaundice or previously damaged biliary tree
• Deranged coagulation – decreased synthesis of vitamin K dependent clotting factors
• Relative immunisuppresion- predisposes to systemic infections and reduces wound healing due to combinations of jaundice

Question 12

Causes of obstructive jaundice

Answer 12

1. CBD stone
2. Pancreatic carcinoma (head)
3. external compression - lymph nodes, large stone in gallbladder neck, metastatic cancer in liver
4. bile duct cancer- cholangiocarcinoma
5. congenital bile duct stricture

Question 13

Symptoms of obstructive

Answer 13

1. Jaundice- yellow sclera, skin
2. dark urine
3. pale stools
4. weight loss
5. itching

Question 14

Investigations of obstructive jaundice

Answer 14

1. Liver function - obstructive picture
2. coagulation tests
3. abdominal ultrasound/CT
4. MRCP
5. ERCP

Question 15

Treatment of obstructive

Answer 15

• depends on cause
• bile duct stones (stones often spontaenously pass)

ERCP + stone extraction+ spincterotomy

Surgical exploraiton of bile duct