Hepatic impairment Flashcards
Why is the uKs health burden to liver disease increasing
Due to alcohol abuse
State the major cause of liver disease in the UK
Alcohol abuse
Hazardous drinking is how may units in men
22-50 units per week
Hazardous drinking is how may units in women
15-35 units per week
In whom is alcohol abus most common in
Affluent middle class
How many people die annually from alcohol lines illnesses
5,500 people
out of 55,000 alcohol related death what causes the highest amount
70% of deaths are due to liver cirrhosis
Are men or women more susceptible to alcohol liver disease
Women
How many people in England and Wales dependent on alcohol
3.8 million
How big is the liver
1.5Kg in healthy adults
Where is the liver situated
In the upper right abdomen directly inferior to the diaphragm and protected by the rib cage
Describe the vascular properties of the liver
- 30% of its blood apple is from hepatic artery
2. 70% of its blood from the portal vein
List the main important functions of the liver
- Processing and Storage of Nutrients Absorbed from the Gut
- Bile Synthesis and Excretion
- Synthesis of Coagulation Factors and Other Proteins
How are nutrients absorbed by the liver
Nutrients absorbed from the intestine travel in the portal vein to the liver where they
are taken up and absorbed by hepatocytes;
What happens to carbohydrates in the liver
They are metabolised to glucose in the liver
What happens to glucose in the liver
Any glucose that is not used immediately as a source of energy is converted to glycogen
Where is glycogen stored
In the liver
Describe glycogen
It can be rapidly converted to glucose when extra energy is required
What can we give to patient who are some from hypoglycaemia
An intramuscular injection of glucagon
What does glucagon do
It converts hepatic glycogen into glucose
When might glucagon not be as effective
If a patient hasn’t glycogen stores eg liver cirrhosis,
Name soem vitamins and minerals stored with in the liver
- Ferritin (iron)
2. Vitamin B12 (80% of body stores).
Why is bile important
It is essential for hydrolysis of dietary lipids by pancreatic lipase
Why do we need to hydrolyse dietary lipids
So that they can be absorbed through the gut wall into the venous blood
What happens if bile is missing in the small bowel
- Dietary fats are not absorbed and result in loss pale fatty stools that float and are difficult to flush away
- The fat soluble vitamins are not absorbed leading to deficiency states
Name the fat soluble vitamins
1, A, D, E and K
Describe bile and what is contain
It is a greenish yellow Liquid that includes:
- Bile salts
- Bilirubin
- Cholesterol
- Electrolytes
- Water
Which cells synthesise bile
Hepatocytes
Where is bile secreted into
- The intrahepatic canaliculi
- Then drains into a system of ducts in the liver
- Drains into the common hepatic duct
How much Bile does the average adult produce
600ml a day
Where can bile temporarily be stored
In the gall bladder
How much capacity for bile does the gall bladder have
50ml
When does bile enter the gall bladder
Ca be stored in the gall bladder before it enters the small bowel via the common Biel duct
why might bile enter the Gall bladder
Usually in repose to lipid rich food entering the duodenum
Where is the junction of the bile duct and duodenum found
Close to the head of the pancreas
What do hepatocytes do
They synthesis:
- the vitamin k dependant coagulation factors II, VII, IX and X
- Albumin
What is albumin
It is major determinant of the blood osmotic pressure
What can reduced albumin levels result in
Tissue oedema
Why is albumin important
important for binding some circulating drugs.
Name the main cells found in the liver
Large population of macrophage lineage cells (Kuppfer cells)
What is the purposes of Kuppfer cells
Positioned to destroy bacteria that may have enters the venous blood, primary by crossing the gut wall
The liver is essential to normal vitamin _ metabolism
D
What is the importance of vitamin D
Promotes the absorption of dietary Ca2+ from the intestine
Which hormone does the liver contribute to the homeostasis of
Sex hormones
What can men with chronic liver disease have
Abnormal sex hormone metabolism which results in clinical feminization and testicular atrophy
How does the liver play a role drug metabolism
Pharmacologically active lipid soluble drugs are converted into pharmacologically inactive hydrophilic metabolites for secretion by the kidneys.
In the UK what is the main cause for liver impairment and failure
- Alcohol induced cirrhosis
- Viral hepatitis
- Congenital causes
List some congenital causes of liver failure and impairment
- Hereditary Haemochromatosis
- Wilson’s disease
- Alpha 1 antitrypson deficiency
What is hereditary Haemochromatosis
A autosomal recessive condition with an incidence of 1 in 200
What does hereditary Haemochromatosis result in
Results in inappropriate deposition of iron in tissues and organ from birth which with time may result in impaired organ function
What is Wilson’s disease
A rare autosomal recessive disease that is characterised by inappropriate deposition of copper in the liver
What is Alpha 1 antitrypson deficiency
A rare autosomal recessive disease where lack of protease Alpha 1 antitrypson results in liver cirrhosis and lung destruction
Where does acquired pathology of liver impairment and failure arise from
- The bile ducts
- The parenchymal cells of the liver
- Th blood vessels
What are liver cells called
Hepatocytes
Where are the smallest vessels of the biliary tree found
Within the liver
Where are the larger terminal vessel and ducts of the biliary tree found
Runs outside of the liver and ultimately into the small bowel
If there is pathology of the liver parenchyma which other organ can get damaged
Secondary damage of the Biel ducts within the liver can occur
Name the most common disorder of the biliary tree
Gallstones
What can gallstones cause
May cause obstructive jaundice
What can biliary tree pathology tropical arise due to
- Lumen obstruction eg gallstones
2. Inflammation and fibrosis of the biliary tree vessel walls
How do gallstones form
They are formed from bile salts by mechanism that are poorly understood
Give some symptoms of gallstones
Majority are asymptomatic but can be associated with: Biliary colic
What is Biliary colic characterised by
Intensely painful spasms as the biliary tree tries to physically move obstructing gallstones
What can happen if bile flow is stopped
An obstructive jaundice may develop
How do we manage gallstones
- Some may spontaneously pass into the small bowel and further intervention is not necessary
- May need physical removal the gallstones
How can we surgically intervene to remove a gall bladder
Passing an endoscope into the common bile duct from an endoscope passed from the mouth to the duodenum
How can we surgically access for removal of gall baldder
- Laparoscopic techniques (‘keyhole’ surgery)
2. An open laparotomy (abdominal incision)
What is Primary Biliary Cirrhosis
A chronic liver disease characterised by progressive destruction of the small bile ducts within the parenchyma of the liver resulting in duct fibrosis and destruction
What can some people develop if Primary Biliary Cirrhosis goes untreated
Can progress to secondary cirrhosis of the liver and associated liver failure
Or secondary Sjögren’s Syndrome;
When do patients usually develop Primary Biliary Cirrhosis
Middle age 50
Are men more likely to develop Primary Biliary Cirrhosis or women
Women (9:1 ratio)
What is the only effective intervention of more likely to develop Primary Biliary Cirrhosis
Liver transplantation but is inly undertaken
What happens in Primary Sclerosing Cholangitis (PSC)?
Progressive fibrosis inflammation of bile ducts within and outside the liver parenchyma
What happens if Primary Sclerosing Cholangitis is left untreated
Ultimately cirrhosis develops and liver translation may be necessary
Does Primary Sclerosing Cholangitis affect men more or women
Typically affects men younger than 50 year olds
What is Primary Sclerosing Cholangitis assocated with
Ulcerated colitis in 70-80% OF CASES
Cholangiocarcinoma develops in 20-30% of those with PSC.
List some acquired disorders of the liver parenchyma
- Hepatitis
- Cirrhosis
- Liver cancer
What does hepatitis literally mean
Inflammation of the liver
What can hepatitis be caused by
- Infections
- Drugs and toxins
- Autoimmune diseases
- Errors of metabolism
- Crytogenic
Name soem viral infections that can cause hepatitis
Hep A, B, C, and E
Herpes virus
Name the major global cause of liver impairment
Hepatitis C
Give examples of herpes viruses that can lead to hepatitis
- pstein Barr Virus (the cause of ‘glandular fever),
- Cytomegalovirus
- Varicella Zoster Virus (the cause of chickenpox).
Which drugs and toxins can cause hepatitis
- Alcohol
- Prescription paracetamol
- Recreational drugs like ecstasy
Give examples of autoimmune disease that can lead to hepatitis
Autoimmune hepatitis
What errors of metabolism can lead to hepatitis
- Haemochromatosis
- Wilsons disease
- Alpha 1 antitrypsin deficiency
What is cryptogenic
When the cause for chronic hepatitis is unknown
If hepatitis persists what can it lead to
liver cirrhosis
What is liver cirrhosis
It is a diffuse abnormally of the liver characterised by inappropriate regeneration and fibrosis with formation of structurally abnormal nodules incapable with normal liver function
Why might cirrhosis arise
As a consequence of:
- Hepatocyte damage
- Biliary tree pathology within the liver
Is a case of liver cirrhosis always found
No in 1/3 of case A cause for cirrhosis may not be identified (‘cryptogenic’)
Name the 2 types of liver cancer
Primary and secondary
Give an example of primary liver cancer
hepatocellular carcinoma
What is secondary liver cancer
metastatic from another site
How common is hepatocellular carcinoma
Uncommon an don accounts for 1 in 200 of all new cancers
List several conditions that can predispose to development of hepatocellular carcinoma
- Chronic hepatitis B or C infection
- Aflatoxin from Aspergillus flavus
- Parasitic infections such as schistosomiasis
Name the main risk factors for liver cancer in the UK
- Chronic alcohol abuse (most common)
- Primary biliary cirrhosis (PBC)
- Haemochromatosis
How common is secondary cancer
In the UK there are approx 70,000 new cases of metastatic liver involvement every year
Where does the liver receive blood in health
- Arterial blood from the heart
2. Venous blood from the gut
Give examples,es of acquired disorders fo shelver vasculature
- Portal hypertension
- Gastro-Oesophageal Varices
- Splenomegaly
What is the portal of the liver
Is is the main fissure where the large blood vessels enter and leave the parenchyma of the liver
What does portal hypertension refer to
Raised venous pressure in liver venous system
Give examples of causes of portal hypertension
- Any state that impaired capillary blood flow through the parenchyma of the liver
- Abnormalities of large vessel circulation
Abnormalities of which large vessels can lead to portal hypertension
- Right heart failure
2. Portal vein thrombosis due a hypercoagulable state
What can portal hypotension result in
Venous connections between the liver and local tissues inappropriately opening and carrying much larger volumes of blood than they do in health
What are Varices
Abnormal dilation or enlargement of veins
Where can Varices develop
In the upper stomach and lower oesophageal
What can happen to gastro-oesophageal Varices c
They may haemorrhage
What can the haemorrhage of gastro-oesophageal Varices cause
- Slowly results in anaemia
- haematemesis (vomit blood)
- May exsanguinate (bleed to death) unless urgent intervention occurs
What is haematemesis
Vomiting blood
What is exsanguinate
bleeding to death
How can we intervene to stop exsanguinate
- Apply pressure to the bleeding varices
- Sclerose the bleeding varices by injecting irritant chemicals
- Shutnting the blood away from the varices by providing an alternative route fro it to pass
What is Splenomegaly
When the venous connections between the liver and spleen become engorges with blood and enlarges
What is Splenomegaly associated with
Hypersplenism
What does hypersplenism increase destruction of
- Erythrocytes via haemolysis with an increased risk of anaemia; and
- Platelets: thrombocytopenia with an increased risk of prolonged bleeding.
What is thrombocytopenia
Reduced platelet count
List some clinical features of liver impairment and failure
- Acute liver failure
- Chronic live failure
- Jaundice
- Prolonged bleeding
- Hepatorenal syndrome
- Malnutrition, Fluid Overload & Ascites
- Nail cahnges
- Palmar erythema
- Spider naevi
- Hepatic encephalopathy
What is acute liver disease
The abrupt loss of normal hepatic functions
What is acute liver disease associated with
High morality and mortality
List some causes of drug induces necrosis causing acute liver disease
- Paracetamol overdose
- Idiosyncratic drug reactions
- Recreational drugs eg ecstasy
Name the most common cause of acute liver failure in the UK
Paracetamol overdose
Give the features of chronic liver failure
Jaundice
What is another name for jaundice
icterus
Name the commonest clinical sign of significant liver impairment
Jaundice
What is jaundice caused by
Increase in bilirubin levels to around 40 micro moles per litre
What is the normal level of bilirubin in the blood
19μmol/L
Where might we clinically see depositions of bilirubin
- Sclera (white of the eyes)
2. Skin and mucous membranes
What can jaundice be caused by
- Premature erythrocytes destruction in the blood
- Parenchymal liver disease
- Obstruction of the biliary tree
What can parenchymal liver disease prevent
Prevents normal excretion of bilirubin in bile in to the bile ducts which results in raised levels of bilirubin in the blood
What can happen if the biliary tree gets obstructed
Prevents normal flow of bile in to the small bowel with resultant raised levels of bilirubin in the circulating blood
List some clinical signs of impaired coagulation in liver disease
- Ecchymoses (bruises) of the skin or mucous membranes
2. Prolonged bleeding following trauma
How can malnutrition results following chronic liver impairment
Multifactorial basis:
- Lifestyle factors
- Impaired intestinal absorption
- Impaired ability of the liver to process the nutrients effectively
- Loss of muscle bulk
How can fluid overload result following liver disease
Reduced hepatic synthesis of plasma proteins leads to excess loss of fluid from the capillaries into the tissues and body cavities as the venous capillary blood lacks the osmotic potential to draw the tissue fluid back into the vessels.
Give examples of clinical manifestations of fluid overload
- Tissue oedema
2. Ascites
What are ascites
Free fluid in the abdominal cavity
How much volume can ascites hold
70 litres
What can ascites result in
- An increase in total body mass
- Impaired respiration due to restriction of diaphragm movement
- Gross distension of the abdomen with thin limbs due to the loss of muscle mass
What changes can happen to the nails following liver disease
- Leuconychia
2. Finger clubbing
What is Leuconychia
White fingernails
Why does Leuconychia occur
Due to chronic low protein levels
What is Palmar erythema
Red palms
What are spider naevi
Small dilated capillaries radiating away from a central red arteriole
how can hepatic encephalopathy present itself as
- Drowsiness
- A flat affect in mood
- Montone speech
- Tremor
- Poor muscular coordination including difficulty with handwiritn g
Give some clinical features of altered steroid hormone metabolism
- Increased levels of oestrogen
- Gynaecomastia (breast enlargement) in men;
- Decrease in body hair
- Testicular atrophy and
- Male impotence
What is Gynaecomastia
Breast enlargement
How can we diagnose and monitor liver impairment and failure
- Liver function tests (LFTs)
- Prothrombin time
- Blood tests
- Imaging
- Liver biopsy
When taking an LFT what are we looking fro
Levels of:
- Bilirubin
- Alkaline phosphatase
- Alanine transferase
- Albumin
Where is bilirubin usually excreted from
Hepatocytes into the biliary canaliculi within the levels
When might bilirubin levels rise
- Excess production of bile
2. Obstruction of bile flow into the small bowel
What is alkaline phosphatase produced by
Bile ducts
When are levels of alkaline phosphatase raised
When there is bile duct obstruction or pathology
What is Alanine transferase produced by
Hepatocytes
When are levels of Alanine transferase raised
When there is damage to the liver parenchyma
What is albumin produced by
Hepatocytes
When are levels fo albumin reduced
When there is chronic damage to the liver parenchyma
What is prothrombin time
A measurement of the prothrombin time of a venous blood sample
What can prothrombin time give us an indication of
Liver function at that point in time
How can prothrombin time be expressed
International Normalised Ratio (I.N.R)
What is prothrombin time influenced by in liver disease
- Degree of hepatocyte damage resulting in reduced systnetus of vitamin K dependent coagulation factors II, V, VII, IX
- Reduced vitamin K absorption fromt eh gut
Which coagulation facto has the shortest half life
Factor VII
What images can we take to assess liver function
- Ultrasound or MRI scanning
2. Cholangiography
What is a crucial functions of the liver
Metabolism of drugs
Hepatic impairment can have a profound affect on drug…?
- Pharmacokinetics
2. Pharmacodynamics
What is the activity of some drugs influenced by
Their degree of protein binding which can be changed in hepatic impairment
What is Pharmacodynamics
The sensitivity of the target tosses to specific drugs may be other increased or decreased With potentially adverse effects
Name some drugs used in oral healthcare what we need have caution in patients with liver impairment or failure
- Aspirin
- NSAIDs
- Opioid analgesics
- Paracetamol
- Erythromycin;
- Flucloxacillin;
- Metronidazole;
- Tetracyclines;
- Fluconazole, miconazole and similar drugs
- Lignocaine
Why do we have to be careful when giving aspirin to patients with liver failure
Risk of increased prolonged bleeding
May cause reyes syndrome in children
Why do we have to be careful when giving NSAIDs to patients with liver failure
- Risk of prolonged bleeding;
2. May worsen renal impairment or precipitate renal failure.
Why do we have to be careful when giving opioid analgesic to patients with liver failure
May cause coma
Why do we have to be careful when giving paracetamol to patients with liver failure
May cause lever encores and acute failure
What is reyes syndrome
It is a rare condition in children and adolescents
What is reyes syndrome characterised by
- A portable viral infection
2. A n advise drug reaction aspirin
What can happen to a child with reyes syndrome
They rapidly become ill with a multi-system illness that primarily affects the liver and brain with non-specific changes such as: • Vomiting; • Drowsiness; • Irritability; • Confusion; • Aggressive or irrational behaviour; • Convulsions; and coma.
Is reyes syndrome Fatal
Mortality is very high 90%
Death occurs within days
What should not be prescribed to children with reyes syndrome
Aspirin
How can we support liver function in liver failure
Renal dialysis awaiting organ transplantation
What is the aim of management for liver failure
- Control symptoms related to liver impairment
- Limit any further liver damage
- Improve liver function
- Undertake organ transplantation at the appropriate time in those close to end stage liver failure
Name the only effective intervention for liver failure
Liver transplantation
Where do most donor livers originate from
Patients who are brain stem dead but still have a beating heart
A small number of transplants involve donation from a live donor
How probable is graft survival
80% at 1 year
Why might grafts fail
Due to recurrent of the pathology that caused the liver failure
Alcohol abuse
What information do we need to from patients with liver disease
- Underlying causes for liver disease
- Known or unknown blood bounce virus infection risk
- Problems with prolonged bleeding
- Past, current or planned
- Does patient have concerns fro oral health
How can dentins contribute to the diagnosis fo liver impairment
- Oral manifestations of decadency states eg low levels of ferritin or vitamin B12
- Increased propensity for infections such as oral candidiasis or delayed soft tissue wound healing
- Oral manifestations leading to unexplained dryness and secondary Sjogren’s Syndrome with Primary Biliary Cirrhosis.
How can dentists contribute to the patients quality of life
- Maintenance of oral health
2. Recognition and management of orofacial symptoms linked to liver impairment
Is a patient with liver failure always going to have the same oral hygiene
no circumstances change with time in respect to:
- The situation of an individual patient
- Understanding and managing of the disease
What considerations do you need to take in regards to a liver patients dietary and oral hygiene
- Impaired liver function may be associated with poor control of blood glucose levels
- Soem patients need to snack on carbohydrates through the day to avoid hypoglycaemia
- Patients can have a higher number of sugar exposures in a day
- Take availably into account before planning love dental procedures
What are some of the side effects of liver therapeutic intervention
Immunosuppressants or immune modulating drugs, for example following liver transplant can affect oral hygiene