Session 7 - Jaundice, Hepatic Portal tension and pancreatitis Flashcards
How does the liver generate aminoacids?
Transamination
What three things are we looking for in a liver function test?
- Hepatocellular damage
- Cholestasis of bile ducts
- Level of synthetic function
What can be detected in hepatocellular damage?
• Aminotransferases
○ ALT/AST
What can be detected in Cholestasis?
- Bilirubin - Unable to excrete bilrubing, plasma concentration rises
- Alkaline phosphatase - Enzymes in cells lining liveres biliary ducts. Plasma levels rise with an obstruction.
What can be detected to determine the synthetic function of the liver?
- Albumin - Levels reduced in chronic liver disease
* Prothrombin time (clotting) - Measures clotting tendency of blood
What is jaundice?
• Damaged hepatocytes have a reduced capacity to excrete bilirubin
Bilirubin accumulated in blood, giving jaundice
What does hyperbilirubinaemia result in?
• A yellowish pigmentation of the skin, conjunctival membranes over the sclera and other mucus membranes
At what point is jaundice clinically detectable?
• >40umol/l of bilibrubin in blood
What are three types of jaundice we must learn to distinguish between?
- Pre-hepatic
- Hepatic
- Post hepatic
What occurs in pre-hepatic jaundice?
• Excessive Bilirubin Production, usually due to an increased breakdown of red blood cells (haemolysis)
○ Liver unable to cope with excess bilirubin
What would the labfindings be in a test for pre-hepatics jaundice?
- Unconjugated hyperbilirubinaemia
- Reticulocytosis
- Anaemia
- Increased LDH
- Decreased Haptoglobin
What is haptoglobin?
• Molecule which binds haemoglobin, marking it for destruction
Give three causes of pre-hepatic jaundice
- Inherited
- Congenital hyperbilirubinaemias
- Acquired
What three traits can be inherited which may cause pre-hepatic jaundice?
- Red cell membrane defects (spherocytosis)
- Haemoglobin abnormalities (sickle cell)
- Metabolic defects
Give the main type of congenital hyperbilirubinaemias
• Gilbert’s syndrome - 10% population
Give six acquired causes of pre-hepatic jaundice
- Immune
- Mechanical ß E.g. RBC’s running across metal heart valves
- Acquired membrane defects
- Infections
- Drugs
- Burns
What occurs in hepatic jaundice?
• Reduced capacity of liver cells to secrete conjugated bilirubin into the blood
What would the labfindings be in a test for hepatics jaundice?
- Mixed unconjugated and conjugated hyperbilirubinaemia
- Increased Liver enzymes (ALT/AST)
Abnormal Clotting
Give five causes of hepatic jaundice
- Congenital
- Hepatic inflammation
- Drugs
- Cirrhosis
Hepatic tumours
Give a main cause of congenital hepatic jaundice
• Gilbert’s syndrome
Give 5 main causes of hepatic inflammation as a cause of hepatic jaundice
- Viral (Hepatitis A, B, C and E, Epstein Barr Virus (EBV))
- Autoimune hepatitis
- Alcohol
- Haemochromotosis
- Wilson’s disease
Give a drug which causes hepatic jaundice
• Paracetamol
Give three main causes of cirrhosis as a cause of hepatic jaundice
- Alcohol
- Chronic hepatitis
- Metabolic disorders
Give two main causes of hepatic tumours
• Hepatocellular carcinoma
Metastases
What is post-hepatic jaundice caused by?
• Obstruction to drainage of bile, causing a back up of bile acids into the liver. Can be intrahepatic or extrahepatic. The passage of conjugated bilirubin is blocked.