Liver function tests Flashcards
Whats cholestasis
Inability of liver to secrete bile into duodenum
What is one manifestation of liver disease
Hepatomegaly (occurs in alcoholic patients mostly)
signs and symptoms of liver disease
Jaundice and pruritus (intense itching of skin)
Nausea and vomiting
Hepatomegaly
Ascites
Dark urine and pale stools in cholestasis
Spider nave in alcoholic liver disease
What is jaundice due to
Increased level of bilirubin
Causes of liver damage
Can be acute or chronic
- Infection
- Adverse drug reaction
- Alcohol abuse
- Obesity (cirrhosis)
- Cancer
What test to do to see if there is hepatocellular damage in kidneys
Aminotransferases
How to test if there is obstruction in the kidneys
Alkaline phosphatase
Gamma GT
How to test if there is damage to synthetic function of kidney
Albumin
Coagulation (INR)
when are levels of bilirubin increased
- Bilary obstruction (cholestasis)
- Hepatocellular damage
- Haemolysis
When is bilirubin mainly increased
Breakdown of RBCs
How is bilirubin formed and excreted
1) RBCs broken down
2) Iron and global reused, biliverdin is formed from haem and reduced to bilirubin
3) Bilirubin is unconjugated and water insoluble
4) The liver conjugates bilirubin to make it water soluble and excreted as bile
What are the different aminotransferases that you test for when testing for hepatocellular damage
AST (aspartate)
ALT (alanine)
When would aminotransferase levels be particularly raised
paracetamol overdose
How can you use aminotransferase tests to see if there is alcoholic liver disease
If the AST:ALT ratio is more than 2:1
Why are alkaline phosphatases tested
TO check for cholestasis
-However can also be raised in infiltration of liver e.g. metastasis
When are Gamma GTs raised
alcohol
Cholestasis
Cellular damage
What does INR indicate
Synthetic activity and coagulation - indicates both acute and chronic damage
When to take LFT when starting a new drug treatment
Before and during treatment to see if there has been any change
What test results would you expect to see in acute hepatitis
Increased ALT and AST (aminotransferases)
increased or normal: ALP, bilirubin, GGT, INR and Normal Albumin
What test results would you expect to see in cholestasis
Increased: ALP, GGT, bilirubin
Normal or increased: ALT, AST, INR
normal: albumin
What test results would you expect to see in chronic liver disease
Increased: Bilirubin, albumin and INR (sometimes GGT)
Normal or increased: ALP, ALT and AST
What is prehepatic jaundice
Water insoluble unconjugated bilirubin produced faster than liver can conjugate it for excretion
-OFten due to haemolytic (haemolytic anaemias such as spherocytosis)
What is Gilberts syndrome
patients have reduced level of UDP which makes bilirubin more soluble so they have more bilirubin than normal
What is hepatocellular jaundice
Liver damaged so can’t process bilirubin and make it water soluble
Causes of intrahepatic cholestasis
- Primary biliary cirrhosis: -autoimmune damage to bile ducts
- Hepatocellular damage
- IN pregnancy with unknown cause
Causes of extra hepatic cholestasis
- Gallstones
* Ca head of pancreas
What is obstructive jaundice
Cholestasis
- GGT and ALP not excreted and are elevated
- liver can convert insoluble bilirubin in the liver to water soluble bilirubin
- But cannot excrete bilirubin in the bile so pale stools
- Water soluble bilirubin excreted in the urine so dark urine and bilirubin in the urine conforms obstructive jaundice
What is NASH
Non-alcoholic steatohepatitis
- Most common liver disease. Non-alcoholic fatty liver with insulin resistance. Fat accumulates in liver, inflammation and can progress to cirrhosis
- Associated with obesity
- Responds to weight loss
How to treat jaundice
Colestyramine
How to treat ascites
Spironolactone (+furosemide+ NaCl restriction)
What is encephalopathy
Neuropsychiatric symptoms which are presented as:
- Changes in personality
- Disorientation
- Confusion and drowsiness
- Sensitivity to centrally acting drugs
How to treat encephalopathy
Neomycin/metronidazole and lactulose
Complications of liver disease and how to treat
Impaired coagulation Gastric bleeding (prescribe ranitidine) Bleeding oesophageal varies (prescribe beta blockers)
What does a fibroscan measure
Elasticity
