Liver disease Flashcards
What are 4 examples of liver issues?
- Viral liver disease (Hep virus)
- Jaundice
- Cirrhosis
- Liver failure
What is jaundice caused by?
- Accumulation of bilirubin in the skin (causes pigmentation and itch in the skin)
What is another term for jaundice?
- Icteric
What is the sclera of the eye?
- The white of the eye
Where is the first place that jaundice will be obvious?
- In the sclera (white) of the eye
What 3 stages can jaundice be divided into?
- PRE-hepatic
- Hepatic
- POST-hepatic
What can cause PRE-hepatic jaundice? (3 points)
- Autoimmune, spleen, abnormal RBC’s
What can cause ‘hepatic’ jaundice? (2 points)
- Cirrhosis
- Hepatitis
What can cause POST-hepatic jaundice? (3 points)
- Biliary, gall bladder and pancreatic disease
What happens in normal bilirubin metabolism?
- There are small amounts of unconjugated bilirubin in the blood
- This is passed into the endoplasmic reticulum of hepatocytes
- Then moves into the bile duct as conjugated bilirubin
What is pre-hepatic jaundice usually caused by? (5 points)
- Excessive quantities of RBC breakdown products:
- Haemolytic anaemia
- Post transfusion (bad match)
- Neonatal (maternal RBC induced)
This results in too much bilirubin in the blood so much so that you overload the livers ability to conjugate
What is the name of the disease caused by prehepatic jaundice?
- Gilbert’s disease
What is hepatic jaundice caused by? (4 points)
Due to ‘liver failure’:
- Cirrhosis
- Drug induces liver dysfunction
Prevents metabolism of RBC breakdown products
What is post-hepatic jaundice caused by?
- Obstruction to bile outflow
Post-hepatic jaundice is caused by obstruction to bile outflow. How can this occur? (3 points)
Intrahepatic biliary system:
- Primary biliary sclerosis
Extrahepatic biliary system:
- Gall bladder (gall stones)
- Common bile duct (pancreatic carcinoma, cholangiocarcinoma)
What is Cholangiocarcinoma?
Bile duct cancer
What are the clinical features of jaundice? (4 points)
- Conjugated bilirubin is excreted in the urine and faeces
- Colour changes with cause of jaundice
- Pale stool & dark urine suggests POST-hepatic cause (conj B causing the jaundice)
- Normal in haemolytic (excess B is unconjugated)
How can gall stones cause obstructive jaundice?
- By blocking the biliary tree
- Can cause inflammation
Where do gall stones form?
- In the gall bladder
What is acute cholecystits?
Inflammation of the gall bladder
What are the symptoms of gall stones? (4 points)
- Pain in shoulder tip
- Abdominal pain right side (radiates tot he back)
- Pain brought on by eating fatty food (stimulates bile release by contraction of the gall bladder)
- Usually gall stones (rarely cholangiocarcinoma (bile duct cancer))
How do gall stones form?
Because you have bile that is super saturated - forms crystals and stones in some
What categories of the population can be more prone to getting gall stones? (5 points)
- Fair hair
- Fertile window
- Female
- Fat
- Forty
What are the possible options of imaging a jaundiced patient? (3 points)
- Ultrasound
- Plain radiographs
- ERCP
An ultrasound is one way of imaging a jaundiced patient. What does this show? (2 points)
- Detects dilated bile channels WITHIN the liver
- Also dilated biliary tree
A plain radiograph is one way of imaging a jaundiced patient. What does this show?
- Shows radiopaque gall stones
ERCP is a method of imaging the jaundices patient. What does this stand for and how does it work?
- Endoscopic Retrograde Cholangiopancreatography
- Contrast radiograph of biliary tree (inject dye into the bile tree to see if there is a blockage)
What is a consequence of chronic pancreatic disease?
Diabetes
What is pancreatitis?
Inflammation of the pancreas
If a patient has pancreatitis and cystic fibrosis what would they need to do?
- Need oral pancreatic enzyme supplements
Does alcohol have a aetiological role in chronic pancreatitis?
- Yes
How would you manage pre-hepatic jaundice?
- Identify and treat the cause
How would you manage post-hepatic jaundice? (3 points)
Remove the obstruction:
- Gall stones via ERCP
- Gall stones via lithotripsy (ultrasound)
- Force open channel with a stent
What is lithotripsy?
Using sonic waves to break down the gall stones (removes the obstruction)
What is a biliary tree stent?
- Little bit of metal mesh which opens up the duct to allow the bile to flow through
- Takes away obstructive jaundice
If a patient has a tumour, is a biliary tree stent a permanent solution?
No, the tumour will get bigger and will eventually squash the stent
How can you manage jaundice by the prevention of gall stone recurrence? (3 points)
- Remove the gall bladder (cholecystectomy)
- Prevent build up of bile acid (Ursodeoxycholic acid, or low calorie and low cholesterol diet)
- Prevent bile acid reabsorption from the GIT (Colestyramine)
What is the name of the procedure that removes the gall bladder?
- Cholecystectomy
What can neonatal jaundice cause? (3 points)
- Increased haem breakdown (birth trauma, ABO & Rhesus incompatibility)
- Poor liver function on neonate (worse if <37 weeks gestation)
- Risk of KERNICTERUS (brain damage from bilirubin)
Neonatal jaundice can cause a risk of KERNICTERUS. What does this mean?
- Brain damage from high levels of bilirubin in the brain
If a baby has neonatal jaundice, what is the treatment option for this?
- Phototherapy
- Blue wave length light - energy is enough to break down the B that is in the skin
What can cause acute liver failure?(2 points)
- Paracetamol poisoning (any med could potentially do this)
- Other drug reactions
What can acute liver failure lead to? (2 points)
- Sudden loss of liver function
- Rapid death (bleeding, encephalopathy)
What is encephalopathy?
Damage to the brain due to the presence of toxic materials
How many paracetamol tablets in one go is enough to push a patient into the toxic area?
- 20 tablets
what are 3 examples of chronic liver failure?
- Cirrhosis
- Primary liver cancer
- Secondary liver cancer (metastasis)
What is Cirrhosis?
- Mixed picture of damage, fibrosis & regeneration of liver structure
What is the possible aetiology of cirrhosis? (6 points)
Multifactorial aetiology:
- Alcohol
- Primary biliary cirrhosis
- Viral disease - chronic active hepatitis
- Autoimmune chronic hepatitis
- Haemachromatosis
- Cystic fibrosis
What are possible signs and symptoms of cirrhosis? (6 points)
- Large or small liver
- Acute bleed - portal hypertension (oesophageal varices)
- Jaundice
- Oedema & ascites (abdominal fluid)
- Encephalopathy
- Spider naevi, palmar erythema (high oestrogen levels from reduced metabolism)
What is ascites?
- The accumulation of fluid in the peritoneal cavity
What is spider naevi?
A spider nevus is a collection of small, dilated arterioles (blood vessels) clustered very close to the surface of the skin. The cluster of vessels is web-like, with a central spot and radiating vessels
What is palmar erythema?
A reddening of the palms, especially around the base of the little finger and thumb
What does ascites cause? (2 points)
- High portal venous pressure
- Low plasma protein synthesis (lower oncotic pressure)
What are oesophageal varices and when do they develop? (2 points)
- Abnormal, enlarged veins in the tube that connects the throat to the stomach
- Develop when normal blood flow to the liver is blocked by a clot or scar tissue in the liver
What are the 2 functions of the liver that are lost when someone has liver failure?
- Loss of SYNTHETIC function
- Loss of METABOLIC function
In liver failure the liver looses its synthetic function. What is this?(2 points)
- Stops producing plasma proteins (transport proteins and gamma globulin)
- Stops making clotting factors (bleeding from loss of this)
In liver failure the liver looses its metabolic function. What is this?(3 points)
- Drug metabolism (esp. 1st pass metabolism)
- Detoxification
- Conjugation of RBC breakdown products
When using liver function tests, what are you actually testing?
- Testing liver inflammation
What is the most useful test for liver function?
- International normalised ratio (INR)
What was traditionally used to test liver function?
- Typically use hepatic cell enzyme levels (ALT, GTT)
- Raised in liver inflammation
- Proportional to the number of hepatic cells (falls in end stage liver disease)
What does an INR measure?
- Measures PROTHROMBIN time against a control
- Prothrombin -> thrombin
What is the normal value for an INR?
- 1
If on WARFARIN, what should the therapeutic value of an INR be?
Range should be 2.0-4.0
If the INR of a patient is not 1 then what does this indicate in relation to liver function?
- Shows there is a SIGNIFICANT liver synthetic dysfunction (i.e. not enough clotting factors)
If someone has liver failure it is likely that they will have fluid retention. What is the name for this?
- Ascites
If someone has liver failure they will have a raised INR and prolonged bleeding. What is considered high for a non warfarin patient?
- 1.3 is considered HIGH
If someone has liver failure it is likely that they will have portal hypertension. What causes this? (2 points)
- Inability of GI blood to re-enter the vena cava
- Leads to oesophageal vein dilation (varices)
Liver failure can lead to the inability of the body to remove ‘waste’. What can this lead to?
Encephalopathy
Liver failure can lead to a build up of breakdown products. What does this lead to?
- Jaundice
When is ‘supportive’ treatment of liver failure given? (2 points)
- End stage disease
- (not?)Acute failure - recovery likely
Is an artificial liver a treatment for liver failure?
- Not really a solution - it is at the experimental stage
What is the only ‘cure’ possible for liver failure?
A liver transplant
Why can a liver transplant procedure be risky?
- As vascular anatomy is a bit unpredictable so can be risky as the patient can die on the table
How many chunks can the liver be split into but still function?
3
Is alcohol cessation useful in reducing severity of liver failure?
- Yes
What are metabolic consequences that dentist need to be aware of in patients with liver disease? (3 points)
- The prolonged effect of sedatives (avoid IV sedation)
- Reduce drug doses (care with antifungals - avoid miconazole, erythromycin and tetracycline)
- Suitable analgesics? (paracetamol probably safest, NSAID’s INCREASE bleeding risk)
What are synthetic consequences that dentist need to be aware of in patients with liver disease? (3 points)
- Reduced clotting factor synthesis - bleeding tendency
- Reduced plasma transport protein synthesis - drug binding reduce so dose may need reduced
- Reduced ‘gamma globulin’ synthesis - more prone to infections?
Do patients with hepatic disease have a problem with LA?
- No, as metabolised in the plasma, not the liver
