liver disease diagnosis and treatment Flashcards
what enzymes and proteins are measured in LFTs
aspartate transaminase (AST), alanine transaminase (ALT), gamma glutamyl transferase (GGT), alkaline phosphatase (ALP), bilirubin, albumin, prothrombin time, urea and ammonia
what is the role of aspartate transaminase (AST) and its therapeutic range
plays a role in gluconeogenesis but not liver specific - 5-40 IU/L
what is the role of alanine transaminase (ALT) and its therapeutic range
plays a role in gluconeogenesis but is more specific to the liver - 5-30IU/L
what is the role of gamma glutamyl transferase (GGT) and its therapeutic range
Catalyses transfer of gamma glutamyl moiety of glutathione to an amino acid, peptide or water - 5-45IU/L, high in biliary obstruction
what is the ratio of ALT:AST
> 2 - alcohol
<1 - other causes
what is the role of alkaline phosphatase (ALP) and its therapeutic range
Removes phosphate groups from nucleotides, proteins and alkaloids - 20-100IU/L
what is the role of bilirubin and its therapeutic range
- Unconjugated from red blood cell breakdown
- Conjugated suggests issue with liver
jaundice at >35umol/L
what is the role of albumin and its therapeutic range
plasma protein synthesised solely by the liver- 60-80g/dL
what is prothrombin time
how long blood takes to clot, should be 10-15 secs
what is the role of ammonia and its therapeutic range
increased in liver disease - 2.5-7.8mmol/L
what effect does liver disease have on drug absorption
increased drug sensitivity
drug clearance
biotransformation
pharmacokinetics
how does liver disease alter drug metabolism
plasma protein changes
hepatic extraction flow
biliary excretion
renal clearance
what does it mean if a drug has a high extraction ratio
Clearance depends on hepatic blood flow
which drugs have a high extraction ratio
morphine
propranolol
metoprolol
verapamil
what does it mean if a drug has a low extraction ratio
clearance depends on metabolising capacity of the liver
what drugs have a low extraction ratio
phenytoin
diazepam
warfarin
atenolol
prednisolone
what are the minor symptoms of acute alcohol withdrawal
CNS hyperactivity
insomnia
tremors
anxiety
sweating
palpitations
what are the more serious symptoms of acute alcohol withdrawal
seizures (12-48hrs)
alcoholic hallucinations
delirium tremens (48-96hrs)
fluid and electrolyte abnormalities
how do you treat acute alcohol withdrawal
- chlordiazepoxide or oxazepam in severe disease/elderly
- IV fluids
- nutritional supplements
what is cholestatic pruritis
Severe itchiness caused by deposition of excess bile salts under the skin
how to treat cholestatic pruritis
underlying cause!
1. cholestyramine
2. non-sedating antihistamines
3. calamine/menthol/aqueous cream
what is ascites
Activation of renin angiotensin system due to renal blood flow reduction causes secondary hyperaldosteronism = fluid retention in abdomen
how to treat ascites
- spironolactone
- furosemide
- rest and fluid restriction
- 0.5-0.75kg reduction/day
what is wernicke korsakoff syndrome
Neurological abnormality due to thiamine deficiency - normally due to malnutrition with alcoholism
how to treat wernicke korsakoff syndrome
IV pabrinex tds for 3-5 days - anaphylaxis risk
oral thiamine at home for prophylaxis
what is hepatic encephalopathy
neurological symptoms due to ammonia and nitrogenous waste products bypassing the liver and crossing the blood brain barrier
how to treat hepatic encephalopathy
- lactulose 30-50ml tds
- rifaximin
- phosphate enema
what is portal hypertension
in severe liver disease there is a disordered anatomy and reduction of blood through the liver
Formation of collateral circulation to compensate and occurs in abdominal area
how is portal hypertension treated
- propranolol - low and slow
- other vasocdilators
what are bleeding oesophageal varices
- Haemorrhage under huge back pressure associated with portal hypertension
how are oesophageal varices treated
- Vasoactive therapy - vasopressin
- Vasoconstriction of blood vessels to reduce BP
- Started ASAP
- Endoscope
- Sclerotherapy - ethanolamine injected to cauterise/stop bleeds
- Ligation/banding
- Balloon tamponade
- TIPS
what causes clotting abnormalities in liver disease
- Liver not producing enough clotting factors
○ Prothrombin time >18secs
how are clotting abnormalities treated
- Phytomenadione IV (vit K)
May not work in severe cases
