Liver- disease Flashcards
Name the 4 lobes of the liver.
Right
Left
Quadrate
Caudate.
What is the function of the gallbladder?
Storage of bile
What is the function of the common bile duct?
Connects the gallbladder to the pancreas and transports bile to the duodenum.
What is the function of the pancreas?
produces digestive enzymes.
What is Jaundice?
The accumulation of bilirubin in the circulation
What is bilirubin?
A natural product of Haem breakdown which should be in a low level in the blood.
What happens if there is a high level of bilirubin in the blood?
- Bilirubin spreads to the skin and accumulates causing yellow skin.
- Bilirubin irritates the nerve endings causing itching.
How is bilirubin excreted?
It is conjugated by hepatocytes which makes it soluble & able to be excreted.
Discuss the types of jaundice?
Pre hepatic- Increased haem load
Hepatic - failure of the liver conjugating the bilirubin
Post hepatic- a blockage of bilrubin removal.
Describe pre-hepatic jaundice
Too much bilirubin overloads the livers ability to conjugate it. This results in more unconjugated bilirubin passing in the blood.
Describe how haemolytic anaemia causes pre-hepatic jaundice?
There is more red blood cells being broken down quicker than they should be increasing the volume of bilirubin in the blood.
Explain how the mixing of blood at birth causes jaundice? (neonatal cause)
The baby’s Blood cells attack and breakdown the mother’s blood cells. Leaving Increased bilirubin in the blood.
What is Kernicterus?
Brain damage due to excessive bilirubin deposits in the brain.
Why do we use blue light therapy to treat jaundice babies?
The blue light breaks down the bilirubin that has accumulated on the skin surface.
Describe causes of hepatic jaundice?
- Less hepatic cells- so less Bilirubin is conjugated
- imapaired enzyme action- so less liver cells can conjugate the bilirubin.
- failure of secretion- Bilirubin is conjugated fine, but the cell membrane is impermeable to conjugated bilirubin .
Describe post hepatic jaundice?
This is due to an obstruction in the billary outflow. A blockage in the biliary tree when bile is added results in a backing up of conjugated and unconjugated bilirubin .
What is Primary biliary sclerosis?
Autoimmune destruction of the bile duct causing buildup in the liver.
How can a pancreatic carcinoma cause post hepatic jaundice?
The tumour squeezes the bile duct and obstructs it
What is a Cholangiocarcinoma?
A tumour of the bile duct .
What does the dark colour of urine mean?
That the bilirubin in the body has been conjuagated.
The patient has dark urine and pale stool.
What type of jaundice has caused this? Explain
post-hepatic.
The dark urine- bilirubin is conjugated and can make it to the kidney for excretion.
Pale stool- conjugated bilirubin cannot make it to the intestine
The patient has dark urine and dark stool.
What type of jaundice has caused this? Explain
Pre hepatic jaundice, as the bilirubin has been conjugated, but there is too much bilirubin produced causing the build up.
The patient has pale urine and pale stool.
What type of jaundice has caused this? Explain
Hepatic jaundice- the bilirubin has not been conjugated, therefore there is no pigment in the urine or stool.
How do you treat Post hepatic jaundice?
- Deal with the gallstones:
- Remove the gallstones by ERCP
- Remove the gallstones by breaking them up using lithotrispy
- Force open the channel using a stent (allowing the jaundice to settle before you decide what next)
- Preventing gallstone reoccurence
How do you prevent gallstone production?
Removal of the gall bladder (cholecystectomy- no longer able to eat fatty foods)
Prevent bile build up (using medications or altering diet)
Use colestryamine to prevent bile resorption from the GIT.
What effect do gallstones have?
They block the bilary tree
Cause inflammation of the gallbladder (acute cholecystitis)
What are the symptoms of a gallstone?
Pain in the shoulder.
Abdominal pain on the right side.
Pain when eating fatty foods.
What are acute liver diseases?
Acute liver disease is when there is a sudden loss of liver function causing rapid death by:
Bleeding- patient cannot produce more clotting factors once the store has been deplete d
Encephalopathy- damage to the brain due to toxic materials.
What is cirrhosis?
Mixed damage fibrosis and regeneration of the liver structure which results in an accumulation of damage meaning fewer hepatocytes can eliminate the waste material.
What are the signs of cirrhosis?
- Portal hypertension-Blood passing through the oesophagus joining vein producing oesophageal varices which can burst
- Jaundice
- Oedema and ascites
- Encephalopathy- when the liver does not detoxify what you eat
- palmar ertheyma and spider navi
What are these?
and what are they caused by?
Spider navi which are enlarged blood vessels.
These are caused by high oestrogen levels.
What is this and what causes it?
Ascites which is build up of fluid in the abdomen
due to liver failure.
Causing High portal venus pressure.
Low plasma protein synthesis
Low oncotic pressure.
What is this and what is it caused by?
Palmar erythema
This is caused by enlarged blood vessels due to the high oestrogen levels
What are the two functions of the liver and what happens to them when the liver fails?
metabolic and synthetic.
These are lost in liver failure.
What effect does the loss of synthetic function of the liver have?
Liver does not produce clotting factors (concern if taking out teeth)
Does not produce plasma proteins:
- Transporting proteins
- Gamma globulin.
In liver failure, what processes are affected when we loose metabolic function?
Loss of:
Drug metabolism- no first pass mechanism ( so drug dose needs to be altered)
Detoxification
Conjugation of RBC breakdown products (causing jaundice)
How do we test liver function?
The INR- internal normalised ratio. This measures prothrombin time (time taken to convert prothrombin to thrombin)
It should be 1 (unless patient is on warfarin)
What should you ask if you don’t know how bad a patient’s liver problem is?
Do they have a specialist doctor for their liver problem?
What are the metabolic consequences for the patient of liver disease?
What does this cause?
They will have abnormal drug metabolism
This will cause:
- Prolonged effect of sedative (so avoid IV)
- Need to reduce drug dosage.
- Cannot give patient’s tetracycline.
What is the most suitable analgesic for a patient with liver disease?
Paracetamol .
Why do you not give a liver disease patient NSAIDs ?
NSAIDs increase bleeding risk.
Why are local anaesthetics not a problem for patient’s with liver failure?
They are metabolised in the plasma- not the liver.
Why does the gallbladder cause pain in the shoulder.
Inflammation of the gallbladder causes irritation of the diaphragm and the phrenic nerve. This supplies to skin on the shoulder.
What is the main blood supply of the liver?
Hepatic portal vein
Compare the dental treatment of patients with moderate liver disease to those with severe liver disease?
Moderate liver disease :
Platelet count >100
Only one blood cell type is affected.
Can treat patient normally but pack the area after an extraction.
Severe liver disease:
Abnormal blood results.
Difficulty with haemostasis (Stopping bleeding)
Need a haemotologist present to treat (hospital)
