Liver disease Flashcards
understand the roles of the liver and implications and signs of liver disease
where is the liver in the abdonmen?
upper right quadrant (left hypochondriac)
what are the functions of the liver?
6
- digestion (produces bile)
- storage (glycogen, copper, iron, vitamins A,B12, D, E, K)
- synthetic (coagulation factors, albumin, thrombopoeitin, IGF-1)
- breakdown (drugs, alcohol, toxins, ammonia, bilirubin)
- immune (filtration of blood, kupffer cells)
- metabolism (carbohydrate, protein, lipids)
what is the blood supply to the liver?
2
- hepatic artery (25%)
- hepatic portal vein (75% from GI tract)
where does the blood from the liver drain to?
hepatic vein
describe the structure of the liver
- arranged into lobules (functional unuits)
- portal triad (arteriole, venule, bile duct)
- central vein in centre of lobule
what are the main cells called in the liver lobules?
hepatocytes
what is the portal triad in the liver comprised of?
3
- arteriole from hepatic artery
- venule from hepatic portal vein
- bile duct leaving liver to bile duct
what are the functional units of the liver called?
lobules
how does liver disease occur?
damage to the hepatocytes
what is liver failure?
the loss of important functions of the liver
what can cause acute liver failure?
2
- paracetamol overdose
- viral hepatitis (A,B,E)
what can cause chronic liver failure?
4
- alcohol
- viral hepatitis (B,C)
- non-alcohol fatty liver disease (NAFLD)
- other - haemochromatosis, autoimmune hepatitis, Wilson’s disease, cystic fibrosis
what are some signs and symptoms of liver disease?
10
- cachexia - wasting of body and muscles due to impaired metabolic funciton
- encephalopathy - brain disturbance due to build up of ammonia
- jaundice - build up of bilirubin
- excoriations - scratches on skin due to itching
- coagulopathy - easy bleeded due to loss of TPO and coagulation factors
- bruising - due to easy bleeding
- ascites - fluid in abdomen due to reduced albumin production = decreased oncotic pressure
- peripheral oedema - fluid in legs due to reduced albumin production = decreased oncotic pressure
- palmar erythema - red palms due to elevated oestrogen levels
- gynaecomastia - development of breast tissue in males (increased oestrogen levels)
how do you manage acute liver failure?
4
- critical care (very unwell)
- supportive measures and invavsive monitoring (Iv fluids, IV glucose, vitamin K, blood products)
- NAC (N-acetylcystein) if paracetamol overdose (prevents hepatocyte necrosis)
- liver transplant - early consideration
what is the maximum dose of paracetamol you can take in 24 hours if adult body weight >50kg?
4000mg = 8 500mg tablets (2 tablets every 4-6 hours)
what is the maximum dose of paracetamol you can take in 24 hours if adult body weight <50kg?
2000mg = 4 500mg tablets (1 tablet every 4-6 hours)
what is the product of broken down paracetamol, what can it cause and what drug can prevent it?
2
NAPQI
* causes hepatocyte necrosis (NAC prevents this)
what are the symptoms of paracetamol overdose after 24 hours, 2-3 days and 3-4 days?
- 24 hours: nausea and vomiting
- 2-3 days: right upper abdominal pain, recurrence of nausea and vomiting
- 3-4 days: signs of acute liver failure
what is cirrhosis?
end stage chronic liver failure
* chronic inflammation and damage to liver cells
* damaged cells are replaced with scar tissue (fibrosis)
what are the stages of chronic liver disease?
5
- healthy
- staetosis inflammation
- fibrosis
- cirrhosis
- HCC (HepatoCellular Carcinoma)
until what stage of chronic liver disease can the liver repair itself?
until fibrosis of the liver
how do you measure the severity of chronic liver disease? what are the different classes?
Child’s-Pugh classification
* A, B, C (C is most severe)
what does fibrosis of the liver lead to?
- increased resistance to the hepatic portal vein blood blow
- results in back pressure of blood in the portal system - portal hypertension
- causes varices (swollen blood vessels) - often at lower part of oesophagus
- high risk of vessel bursting = variceal bleed
what are the stages of alcohol related liver disease?
3
- alcohol fatty liver
- alcohol hepatitis
- cirrhosis
what are the dental implications of alcohol?
6
- oral cancer
- tooth erosion (NCTSL - non-carious tooth surface loss)
- staining
- trauma risk
- caries
- oral hygiene
what are the other health risks of alcohol-related liver disease?
7
- alcohol dependence and withdrawal
- cardiovascular disease
- stroke
- oesophageal, stomach and bowel cancer
- dementia
- depression
- pancreatitis
what is non-alcoholic fatty liver disease?
exessive fat deposition in liver tissue leading to impaired hepatocyte function
what are the stages of non-alcoholic fatty liver disease?
5
- healthy
- fatty liver
- steatohepatitis
- fibrosis
- cirrhosis
what is factors are associated with non-alcoholic fatty liver disease?
6
- obesity
- type 2 diabetes
- poor diet
- sedentary lifestyle
- smoking
- hypertension
how is non-alcoholic fatty liver disease managed?
3
- weight loss
- control of cholesterol
- reducing alcohol intake
what is viral hepatitis? how does it affect the liver?
blood borne viruses that can be transmitted sexually, vertically (mother to child) and IV drug use
* causes chronic liver disease by infecting hepatocytes, damaging them, resulting in loss of function
what are the dental implications of liver disease?
3
- increased bleeding risk = reduced coagulation factor and thrombopoietin (TPO), and increased breakdown of platelets in spleen
- impaired drug metabolism = less plasma proteins for drug binding, more free drug in blood
- alcohol = oral cancer risk, non-carious tooth surface loss (NCTSL), interaction with metronidazole
what blood tests can be used to assess liver disease patients?
4
- full blood count (FBC) - platelet count <50x10^9/L bad
- liver function test (LFT) - bilirubin, albumin and liver enzymesn (for liver inflammation)
- coagulation screen - intrinsic and extrinsic pathways of coagulation cascade
- INR - time taken for blood to clot
