Oral Surgery Flashcards
what does trauma and infection lead to a breakdown of and what does it produce?
Trauma and infection lead to the breakdown of membrane phospholipids producing arachidonic acid
arachidonic acide can be broken down to form what?
Arachidonic acid can be broken down to form prostaglandins
what does prostaglandins do to the tissues?
- Prostaglandins sensitise the tissues to other inflammatory products which results in pain
- They sensitise the tissues to other inflammatory products such as leukotrienes
- So if prostaglandin production decreases, this will moderate the pain
what acid is aspirin?
Acetylsalicylic acid
what are properties for aspirin?
1) Analgesic
2) Antipyretic
3) Anti-inflammatory
4) metabolic
What is mechanism of action for aspirin?
Aspirin inhibits cyclo-oxygenases (COX-1 & 2)
∴ reduces production of Prostaglandins
NB:
* It is more effective at inhibiting COX-1)
* -COX-1 inhibition reduces platelet aggregation (predisposes to damage of the gastric mucosa)
what does aspirin inhibit?
cyclo-oxygenases (COX-1 & 2)
what does aspirin reduce production of?
prostaglandins
what does cox-1 inhibition reduce?
COX-1 inhibition reduces platelet aggregation predisposes to damage of the gastric mucosa)
what actions predominate in relation to analgesic properties of aspirin?
Peripheral actions predominate.
where does the analgesic action result from in aspirin?
The analgesic action results from inhibition of prostaglandin synthesis in inflamed tissues (Cyclo-oxygenase inhibition).
what are prostaglandins and what do they affect in terms of anti-inflammatory?
Prostaglandins are vasodilators and as such also affect capillary permeability.
what does aspirin reduce
Aspirin is a good anti-inflammatory and will reduce redness and swelling as well as pain at the site of the injury
what are potential adverse /side effects of aspirin?
- 1) GIT problems
- 2) Hypersensitivity
- 3) Overdose – tinnitus, metabolic acidosis
- 4) Aspirin Burns – Mucosal
where does GIT problems associated from aspirin tend to happen?
mucosal lining of stomach
explain the effect prostaglandins have on GIT in relation to aspirin?
inhibit gastric acid secretion
Increase blood flow through the gastric mucosa
Help production of mucin by cells in stomach lining (cytoprotective action)
what does prostaglandins inhibit?
inhibit gastric acid secretion
what does prostaglandins increase in relation to GIT and aspirin?
Increase blood flow through the gastric mucosa
what does prostaglandins help production of in relation to GIT and aspirin?
Help production of mucin by cells in stomach lining (cytoprotective action)
what is cytoprotective action?
Help production of mucin by cells in stomach lining (cytoprotective action)
when should their be especially care of in patients with GIT problems and using aspirin?
Ulcers
Gastro-oesophageal reflux
what will patients taking aspirin definitely suffer from in the GIT?
o Most patients taking Aspirin will suffer some blood loss from the GIT (not detectable macroscopically and asymptomatic)
what kind of side effects do you suffer from when taking aspirin?
- GIT problems
- Hypersensitivity
- overdose - tinnitus, metabolic acidosis
- aspirin burns - mucosal
why kind of hypersensitive side effects could people taking aspirin face?
Acute bronchospasm / asthma type attacks
Skin rashes / urticaria / angioedema
Other allergies
what is a life threatening overdose of aspirin be?
metabolic acidosis
what types of overdose reactions can someone with aspirin suffer from?
o Hyperventilation
o Tinnitus, deafness
o Vasodilatation & sweating
o Metabolic acidosis (can be life threatening)
o Coma (Uncommon)
what causes aspiring burns?
salicylic acid
how does an aspirin burn occur?
Aspirin applied locally to oral mucosa results in a chemical burns
what must asprin be taken with?
water
what are the groups to avoid when taking aspirin?
- Peptic ulceration
- Epigastric pain
- Bleeding abnormalities
- Anticoagulants
- Pregnancy/lactation
- Pts on steroids
- Renal/hepatic impairment
- Children and adolescents under 16 years
- Asthma
- Hypersensitivity to other NSAIDs
- Taking other NSAIDs
- Elderly
- G6PD-deficiceny
why don’t you give someone who has a peptic ulcer aspririn?
could result in perforation
why don’t you give someone who has a epigastric pain aspririn?
may have undiagnosed ulcer
why don’t you give somone taking anticoagulants asprin?
- aspirin enhances warfarin and other coumarin anticoagulants
- displaces warfarin from binding sites on plasma proteins
- so more free warfarin
- marjority of warfarin is bound (inactive) if more is released this will become active increasing bleeding tendency
why don’t you give someone who is pregnant aspirin?
- especially in 3rd trimester
- near delivery may cause impairment of platelet function
*increased risk of haemorrhage - increased risk of jaundice in baby
- can prolong delay labour
why don’t you give someone who is lactating aspirin?
could cause reye’s syndrome
why don’t you give someone who is on steroids aspirin?
a quarter of steroid users will develop an ulcer
when is it worst to give aspirin to someone pregnant?
3rd trimester
why don’t you give someone who has a renal/hepatic impairment aspirin?
- aspirin metabolised in liver and excreted in kidney
- if renal impairment - excretion may be reduced/delayed
- not complete contraindication but administer with care and avoid if impairment severe
where are prostaglandins PGE2 and PGI2 synthesised and what are they?
Prostaglandins PGE2 and PGI2 are powerful vasodilators synthesized in the renal medulla and glomeruli respectively, and are involved in the control of renal blood flow and excretion of salt and water
Inhibition of renal prostaglandin synthesis may result in?
- sodium retention
- reduced renal blood flow
- renal failure,
NSAID’s may cause what in kidney?
NSAIDs may cause interstitial nephritis and hyperkalaemia.
why don’t you give children under 16 aspirin?
- could cause reye’s syndrome
what is reye’s syndorme?
- fatty degenerative process in liver profound swelling in brain
why don’t you give people with asthma aspirin?
- not completely contraindicated but ask them if they had problems before?
why don’t you give people taking other NSAIDs aspirin?
increased risk of side effects
why don’t you give elderly aspirin?
- more likely to get side effects
- smaller circulating blood volume
- on other meds
- have other med problems
aspirin is completely contraindicated in who?
- 1) Children & Adolescents under 16 years; breast-feeding (Reye’s Syndrome)
- 2) Previous or active peptic ulceration
- 3) Haemophilia
- 4) Hypersensitivity to Aspirin or any other NSAID
for mild to moderate odontogenic or inflammatory pain what is given?
5 day regime of 300mg aspirin tablets
- 40 tablets
- 2 tablets 4 times daily after food
if pt has or had peptic ulcer what do they get instead of aspirin?
- paracetamol and proton pump inhibitor
- either omeprazole or lansoprazole
- 5 day regime
what does ibuprofen have less effect on compared to aspirin?
Less effect on platelets
what may ibuprofen cause?
bronchospasm
what ibuprofen regime do you take?
- mild to moderate post op pain
- 5 day regime
- 400mg
- 20 tablets
- 1 tablet 4 times daily preferably after food
what is max adult dose of ibuprofen?
2.4g
when is there caution when prescribing ibuprofen?
1) Previous or active peptic ulceration
2) The Elderly
3) Pregnancy & lactation
4) Renal, cardiac or hepatic impairment
5) History of hypersensitivity to Aspirin & other NSAIDs
6) Asthma
7) Patient taking other NSAIDs
8) Patients on long term systemic steroids
what are side effects of ibuprofen?
1) GIT discomfort, occasionally bleeding & ulceration
2) Hypersensitivity reactions e.g. rashes, angioedema & bronchospasm
3) Others: headache, dizziness
what are symptoms of ibuprofen overdose?
- Nausea
- Vomiting
- Tinnitus (more serious toxicity very uncommon)
how is ibuprofen overdose treated?
Activated charcoal followed by symptomatic measures are indicated if more than 400mg/kg has been ingested within the preceding hour.
what is mode of action of paracetamol?
Hydroperoxides are generated from the metabolism of arachidonic acid by COX and exert a positive feedback to stimulate COX activity
- This feedback is blocked by paracetamol, thus indirectly inhibiting COX – especially in the brain
what is main site of action of paracetemol?
central nervous system, such as in the thalamus
cautions when prescribing paracetamol to who>
1) Hepatic impairment
2) Renal impairment
3) Alcohol dependence
what are side effects of paracetemol?
Side effects are rare but:
1) Rashes
2) Blood disorders
3) Hypotension reported on infusion
4) Liver damage (and less frequently kidney damage) following overdose
what is paracetamol regime?
for mild to moderate odontogenic or post op pain
- 5 days
- tablets 500mg
- 40 tablets
- 2 tablets 4 times daily
what is max dose of paracetemol?
Adults: 1-2 tablets (0.5-1g) 4-6 hourly
* Max. Dose: 4g daily (8 tablets)
what dose children paracetamol dose depend on?
: Depends on weight/age – see BNF
what must you always warn patients on for paracetemol?
Always warn patients of maximum dose and emphasise that they should not exceed this!
what may paracetamol over does cause?
severe hepatocellular necrosis, and less frequently, renal tubular necrosis
how much paracetamol overdose is deadly?
As little as 10-15g (20-30 tablets) or 150mg/kg of paracetamol taken within 24 hours may cause severe hepatocellular necrosis, and less frequently, renal tubular necrosis
when is liver damage of paracetamol overdose maximal?
Liver damage is maximal at 3-4 days after ingestion-> LIVER FAILURE -> Death
what is there a lack of and what happens if someone overdoses on paracetamol?
Therefore, despite a lack of significant early symptoms, patients who have taken an overdose of paracetamol should be transferred immediately to hospital
where do opioids act?
spinal cord in dorsal horn pathways
- central regulation of pain
what are problems of opioids?
- dependence
- tolerance
- effects on smooth muscle
- constipation
- urinary and bile retention
what is CNS effect of opioids?
- 1) Pain centre (alters awareness/perception of pain)
- 2) Higher centres
- 3) Respiratory centre
- 4) Cough centre
what are side effects of opioids?
- Nausea
- Vomiting
- drowsiness
Larger doses produce respiratory depression & hypotension
what are effects of opioids enhanced by?
alcohol
who re contraindications of giving opioids to?
Acute respiratory depression
Acute alcoholism
Raised intracranial pressure/head injury
* Interferes with respiration
* Affects pupillary responses vital for neurological assessment
what is codeine taken with?
Usually in combination with NSAIDs or Paracetamol e.g. Co-codamol (8mg Codeine : 500mg Paracetamol)
what is used to treat trigeminal neuralgia?
o 100 or 200 mg tablets
o Starting dose 100mg once or twice daily (but some patients may require higher initial dose)
o Increase gradually according to response
o Usual dose 200mg 3-4 times daily, up to 1.6g daily in some patients
what are other drugs for trigeminal neuralgia?
o Gabapentin
o Phenytoin
what are clinical features of trigeminal neuralgia?
o 1) Severe spasms of pain: ‘Electric shock’, lasts seconds
o 2) Usually unilateral
o 3) Older age-group
o 4) Trigger spot identified
o 5) Females more than males
o 6) Periods of remission
o 7) Recurrences often greater severity
what are 3 basic modes of action for tooth elevation?
- wheel and axle
- lever
- wedge
why do teeth fracture?
o Thick cortical bone
o Root shape
o Root number
o Hypercementosis
o Ankylosis
o Caries
o Alignment
how is debridement done?
- physical
- bone file or handpiece to remove sharp edges
*mitchell trimmer or veronica currette to remove soft tissue debris - irrigation
*sterile saline to into socket and under flap - suction
*aspirate into socket and under flap
*check socket for retained apices
what are aims of suturing?
- reposition tissues
- cover bone
- prevent wound breakdown
- achieve haemostasis
- encourage healing by primary intention
what is haemostasis peri-operative?
LA with vasoconstrictor
Artery forceps
Diathermy
Bone wax