Chempath 25: LFTs And Cases Flashcards
Which 2 vessels supply the liver ?
Hepatic artery
Portal vein
List 3 metabolic effects of Liver failure ?
- low plasma glucose (less glycogen stores)
- High ammonia (less metabolism of amino acids)
- Lactic acidosis (lactic acid not metabolised)
What is the tumour marker for hepatocellular carcinoma of the liver ?
AFP
Which disease is suggested by a AST:ALT ratio > 2 ?
Alcoholic liver disease
AST rises more than ALT in alcoholic liver disease
What does a raised GGT level tell you ?
Chronic alcohol use
Or bile duct disease (if ALP and GGT is raised it means its likely not bone disease and more likely disease of the biliary tract)
What is the best acute marker of liver function ?
PT
Apart from hepatocellular carcinoma which other cancer can cause a raised AFP
testicular cancer
What does an isolated raised ALT suggest ?
Fatty liver disease
What does a raised bilirubin and raised ALP suggest?
Cholestatic liver diseases: Gall stones, PBC, PSC, Cancer
What does a raised bilirubin and raised ALT/AST suggest ?
Hepatocellular disease: Acute hepatitis, chronic liver failure
What causes an isolated raised unconjugated bilirubin ?
Gilbert’s syndrome
Which drug most commonly causes drug-induced cholestasis ?
Augmentin (co-amoxiclav)
What is Courvoisier’s law ?
In the presence of a palpable gall bladder which is non-tender and accompanied by mild painless jaundice the cause is unlikely to be gall stones
What are the 3 stages of xenobiotic modification
chemical modification (p450/ acetylation/deacetylation/ ox/red
conjugation - glucoronate/sulphate
excretion
3 types of hormone metabolism (liver)
vitamin D hydroxylation
steroid hormone conjugation and excretion
peptide hormone catabolism
what makes up bile
water bile salts/acids bilirubin phospholipids cholesterol proteins drugs and metabolites
bile function
excretion
micelle formation
digestion
stages in bile synthesis
red cells broken down heme forms bilirubin bilirubin binds to albumin in the plasma unconjugated bilirubin - liver - glucoronidated conjugated bilirubin released as bile
what is the role of kuppfer cells
clearance of infection and LPS
antigen presentation
immune modulation - cytokines etc
two main tests for liver synthetic function
albumin
PT
what does a raised AST suggest
alcohol and cirrhosis
what does a raised GGT suggest
chronic alcoholism, bile duct disease, hepatic mets
what does a raised ALP suggest
obstructive jaundice, bile duct damage
what are other causes of raised ALP
bone disease, pregnancy
3 main causes of low albumin
low production states: CLD, malnutrition
increased loss: gut, kidney
sepsis: endothelium becomes leaky so albumin leaks out into tissues
Is PT/INR an acute or chronic marker of liver function
acute - half life of most clotting factors is a matter of horus
causes of a raised AFP
hepatocellular carcinoma
hepatic damage/regeneration
pregnancy
testicular cancer
causes of jaundice
ALP - cholestatic - dilated ducts = obstruction/gallstones/cancer
- undilated ducts = drugs/PBC-PSC/pregnancy
ALT/AST - hepatocellular - acute/chronic
Normal enzymes - Gilberts
when is urobilinogen absent
obstructive jaundice
pale stools/dark urine
when is urobilinogen increased
haemolysis/hepatitis/sepsis
how can liver function be measured
- dye tests : indocyanine green/ bromsulphalein
- breath tests : aminopyrine/galactose
- serum bile tests : elevates esp. in cholestasis
what 3 things cause an ALP over 1000
toxins (paracetamol)
viruses (hepatic viruses)
ischaemia (post-rescuscitation)
how is paracetamol OD treated
N-acetylcysteine
In severe cases : liver transplant
