Jaundice Flashcards
What is the bilirubin liver function test?
Bilirubin is elevated as a result of haemolysis, parenchymal damage and obstruction of bile ducts
What is the aminotransferases liver function test?
Enzymes present in hepatocytes therefore elevation suggests parenchymal involvement
What is the alkaline phosphatase liver function test?
Enzyme in bile duct which is elevated in obstruction of bile ducts
What is the Gamma GT liver function test?
A non-specific liver enzyme that is elevated with alcohol use
What is the albumin liver function test?
Albumin synthesis is a key liver function therefore low levels suggest chronic liver disease
What is the prothrombin time liver function test?
Shows degree of liver dysfunction
What is the creatine liver function test?
Shows kidney function and is therefore important for assessing for liver transplant
What is the platelet count liver function test?
Liver cirrhosis results in splenomegaly causing low platelet count
What is jaundice?
Yellowing of the skin, sclerae and mucosae from increased plasma bilirubin levels
What is the pathway of Bilirubin metabolism?
Bilirubin is formed by the breakdown of Haemoglobin
In the liver, Bilirubin is conjugated with glucuronic acid by hepatocytes, making it water soluble.
Conjugated bilirubin is secreted in bile and passes into the gut.
Some is taken up again by the liver and the rest is converted to urobilinogen.
Urobilinogen is either reabsorbed and excreted by kidneys or converted to stercobilin which colours faeces brown.
How is jaundice classified?
By the site of the problem: Pre hepatic, Hepatic, Post hepatic
By the type of circulating bilirubin: Conjugated or Unconjugated
What is unconjugated hyperbilirubinemia?
Unconjugated bilirubin is water-insoluble so it does not enter the urine.
Pre hepatic
What is conjugated bilirubinaemia?
Conjugated bilirubin is water-soluble so it is excreted in urine, making it dark. Less conjugated bilirubin enters the gut and the faeces become pale. When severe it can be associated with pruritis.
Hepatic and Post hepatic
What is Pre- hepatic jaundice?
- Increased quantity of bilirubin (haemolysis)
- Impaired transport
What is Hepatic jaundice?
- Defective uptake of bilirubin
- Defective conjugation
- Defective excretion
What is Post hepatic jaundice?
Defective transport of bilirubin by biliary ducts
What is Pre-hepatic Jaundice associated with?
History of anaemia
Pallor
Splenomegaly
What is Hepatic Jaundice associated with?
IVDU
Drug intake
Ascites
Variceal bleed
Encephalopathy
Spider neavi
Gynaecomastia
Aterixis
What is Post-hepatic jaundice associated with?
Primary biliary cholangitis
Primary sclerosing cholangitis
Cholestasis: dark urine, pale stools, pruritis
Palpable gall bladder (Courvoisier’s sign)
What is cholestasis and what causes it?
Accumulation of bile within hepatocytes or bile canaliculi
- Viral hepatitis
- Alcoholic hepatitis
- Liver failure
- Drugs
What tests are carried out for Jaundice?
Urine- presence of bilirubin
Haematology- FBC, clotting
Chemistry- U%E, LFT, total protein, albumin
Microbiology- hepatitis serology
What imaging modalities are used for Jaundice
- Ultrasound
- Endoscopic retrograde cholangiopancreatography (ERCP)
- Magnetic resonance cholangiopancreatography (MRCP)
- Percutaneous transhepatic cholangiogram (PTC)
- Endoscopic ultrasound (EUS)
