Liver and liver disease Flashcards
What are the functions of the liver?
- protein metabolism
- hormone and drug inactivation
- immunological function
- formation of bile
- lipid metabolism
- carbohydrate metabolism
- form coagulation factors
What are the different liver function tests?
albumin (protein synthesis)
coagulation (PT, INR)
What are the different liver biochemistry tests?
- AST (if AST>ALT = alcohol-induced hepatitis)
- ALT (if ALT>AST = viruses/non-alcoholic fatty liver disease)
- alkaline phosphatase (elevated = biliary obstruction)
- gamma glutamyltransferase(elevated = chronic viral hepatits)
- bilirubin (elevated = jaundice)
How are units of alcohol calculated?
units = strength (ABV) x volume (ml)/1000
Describe the metabolism of alcohol.
ethanol –alcohol dehydrogenase–> acetaldehyde –aldehyde dehydrogenase–> acetate
What is the result of:
- increased acetaldehyde
- increased acetate
- increased NADH
- increased acetaldehyde: uncoupling of mitochondria = reduced ATP
- increased acetate: more fatty acid production
- increased NADH: more G3P production
END RESULT: more triglycerides and reversible cell injury
What are the consequences of alcohol-induced liver damage?
- alcoholic fatty liver
- asymptomatic fat deposits in liver
- liver enzymes normal/moderately raised
- liver will be slightly enlarged and pale yellow
- microanatomy: fat deposits in hepatocytes, especially zone 3 - alcoholic hepatitis
- painful hepatomegaly
- fever
- lots of mallory bodies, neutrophils, hepatocyte swelling
- raised AST, raised ALT therefore raised AST:ALT
- raised gamma GT (alcohol causing microsomal hyperplasia)
How is alcoholic hepatitis managed?
- lifelong alcohol abstinence is vital
- steroids may help in severe cases
- supplements if liver function is permanently compromised
- encephalopathy (deficiency in ammonia removal)
- coagulopathy (deficiency in clotting factors)
What is hepatic encephalopathy? How is it diagnosed and treated?
- precipitated by sepsis, bleeding, drugs (opioids, benzodiazepines), deteriorating liver function
- presents as mild confusion –> coma
Diagnosis:
- hepatic flap
- clinical symptoms
- EEG/MRI changes
Treatment:
- lactulose
- transplantation
What is haematemesis a sign of? How is it managed?
Sign of a complication of fibrosis:
- portal HTN
- variceal bleeding from lower oesophagus
Management:
- resuscitation (blood or albumin)
- correct clotting factor abnormalities
- IV terlipressin: splanchnic vasoconstrictor
- endoscopic banding or scleropathy
- emergency portosystemic compression (sengstaken-blakemore tube)
Describe the different portosystemic shunts.
- oesophageal branch of left gastric vein anastomoses with oesophageal branch of azygos vein –> can pop if engorged with blood
- Paraumbilical vein of HPV anastomoses with superficial epigastric branch of femoral vein
- superior rectal vein of IMV anastomoses with inferior and middle rectal veins of internal pudendal vein
What is the most common chronic blood infection?
Hepatitis C
What causes hepatitis C?
drug use
unprotected sex
transfusion
What family of viruses dos hepatitis belong to?
Flavivirus family
What is the incubation period of HCV?
~2 months