Liver Disease (08/03/19) Flashcards
What are the 2 main blood supplies for the liver?
Arterial (20% hepatic artery) and Venous (80% portal vein)
What are some key functions of the liver?
Metabolism (of hormones, protein, insulin, DRUGS)
Synthesis (of proteins, clotting factors, cholesterol)
Clearance (of bilirubin, drugs, toxins)
Production of Bile
Storage (of fat soluble vitamins (A,D,E,K))
How do you classify liver disease?
Classified by PATTERN OF DAMAGE and TIME COURSE over which damage occurs
What is cholestatic and hepatocellular?
The types of damage that liver disease can cause. This damage can cause both fibrosis and cirrhosis
Define Cholestasis
Liver disease which causes disruption of bile flow.
What causes Cholestasis?
INTRAHEPATIC: issue in biliary ductules
EXTRAHEPATIC: mechanical obstruction
Which enzymes does Cholestasis effect and how?
Causes INCREASE in BILIRUBIN, ALKALINE PHOSPHATASE, and GAMMA-PLUTAMYLTRANSFERASE
Impaired biliary excretion causes what?
Reduced absorption of fatty acids, and accumulation of bile salts which can damage hepatocytes
Define Hepatocellular Disease
Injury to hepatocytes caused by toxins or viruses
What does injury to hepatocytes cause?
1) Accumulation of fat inside hepatocyte = STEATOSIS
2) Inflammation of hepatocyte = HEPATITIS
3) Cell death = NECROSIS
Which enzymes are effected by Hepatocellular disease and how?
INCREASE in TRANSAMINASE, GGT, and BILIRUBIN
Define Fibrosis
Extended and persistent damage to hepatocyte.
This causes disruption of blood flow.
Also causes erratic regeneration and nodules.
Define Cirrhosis
Uncontrolled Fibrosis over a long period of time.
What is the difference between Acute and Chronic liver disease?
Acute= symptoms <6 months. Caused by hepatitis and drugs.
Chronic= symptoms/damage >6 months (permanent structural damage). Further divided into Compensated (remaining part of undamaged liver still keeps body running) and Decompensated (do not have ability to function). Caused by alcohol and chronic viral hepatitis.
How to assess liver function?
Perform liver function test and test following:
Bilirubin: Usual range = 5-20 micromol/L.
Transaminases:
Aspartate transferase (AST) 0-40 iu/L) (found in liver, heart, skeletal muscle, pancrease)
Alanine Transferase (ALT) (5-30 iu/L)
[However, not all liver disease will raise transaminase enzymes)
Alkaline Phosphatase (ALP) range = 30-120 iu/L. Increased in cholestasis, infiltrative liver disease, and damage to biliary tree
Gamma-Glutamyltransferase (GGT) range = 5-55 iu/L. Levels increased by alcohol, cholestasis, carcinoma of pancrease and GIT.
What do bilirubin levels of >50 micromol/L cause?
Clinical Jaundice (yellowing of skin and eyes)
What should you look for in Liver function test?
If 2 or more numbers are off.
The values should be 2 times the Upper limit.
However, liver function test can appear normal, even in damaged livers because the liver is so damaged that it does not make enzymes.
Other factors to assess liver disease?
Recent travel (Hep A), Tattoos (Hep B/C), Alcohol consumption, Medication.
Biopsy, imaging (liver ultrasound, CT/MRI, ERCP and MRCP)
Sign and Symptoms of Liver disease?
Patient may be asymptomatic until severe damage.
Symptoms: fatigue, fever, abdominal pain, Jaundice, itching (pruritsis), pale stools and dark urine, Spider naevi (broken vessels), Bruising and Bleeding,
End stage symptoms:
Ascites,
Oesophageal and gastric varces,
Encephalopthy
Define Ascites
Accumulation of fluid in peritoneal cavity.
SWOLLEN ABDOMEN
Treatment of Ascites
- Fluid/Sodium restriction
- Diuretics (Spironolactone: 100-600mg OD, Furosemide: 40-160mg daily)
What is infection of ascitic fluid called?
Spontaneous Bacterial Peritonitis. Classified by neutrophil count >250 cells
Treated with 3rd gen cephalosporins, co-amoxiclav, tazocin.
Define Hepatic Encephalopathy
Changes in mood and behaviour, confusion, poor sleep, and eventually delirium and coma.
Causes of Encephalopathy
- increased protein load
- reduced ammonia
- electrolyte disturbance
- dehydration
- drugs
