Assessment task 1 Flashcards
1
Q
commonly used local anesthetics
max doses
A
1 Lidocaine hydrochloride 1%
- non proprietary - (no trade name)
- 10 mg/ml
- Rapid onset
- duration: 1,5 hours
- max dose 200 mg - 20 ml of 1% solution
2 Bupivacaine hydrochloride, Levobupivacaine similar
- Marcaine, Chirocaine
- 2,5 mg/ml or 5mg/ml
- slow onset
- Duration 4-6 hours
- max dose 150 mg - 30ml of 0,5% solution
3 Procaine hydrochloride 2%
- nonproprietary
- 20 mg/ml
- Moderate rate of onset
- duration 30 min
- max dose 1g - 200ml od 0,5% solution
2
Q
commonly used
A
1 Hydrocortisone acetate
- Hydrocortistab
- 25mg/ml - 1ml ampoule
- potency 1
- least prolonged
2 Prednisolone acetate
- Deltastab
- 40mg/ml - 1ml ampoule
- potency 4
- second least prolonged
3 Methylprednisolone acetate
- Depomedrone
- 40mg/ml 1,2 and 3 ml vials
- potency 5
- most prolonged
4 Triamcinalone acetonide
- Adcortyl
- 10mg/ml - 1ml ampoules
- potency 1
- second most prolonged
5 Triamcinalone acetonide
- Kenalog
- 40mg/ml - 1ml vials
- potency 5
- second most prolonged
3
Q
A
4
Q
LA actions
A
- systemic absorption after intraarticular or intralesional injection is slow/small
- produce a reversible abolition of nerve conduction
- small diameter, nonmyelinated fibres most easily blocked - nociceptors and sympathetic
- order of blockade:
- pain
- temperature
- touch
- proprioception
- motor
- Duration varies with type of LA
- penetrates nerve sheath in non-ionised (lipophilic) form
- once inside cell, some molecules become ionised and then block sodium channels in cell membrane by binding to receptor site within channel
- opening and closing of sodium channels is required for depolarisation and repolarisation for initiation and transmission of impulses
5
Q
A
6
Q
Corticosteroids
actions
A
- All aspects of inflammatory response depressed
- acute (reduced pain, heat, redness, swelling)
- chronic (proliferation and modelling affected)
- Not suitable for acute inflammation
- protective aspects inhibited
- delay in fibre formation
- some exceptions (bursitis)
- chronic inflamatory phase - the balance of collagen synthesis is interrupted with inflammation and proliferation continuing side by side. Corticosteroid can be beneficial in reducing/abolishing the low grade inflammatory component.
- The unwanted effect on collagen synthesis in the proliferation and remodelling phase is disrupted in:
- topical steroids
- long term large doses suppress collagen
- intermittent doses - no effect
- intralesional corticosteroids
- keloid regression - inhibition of fibroblast activity
- decreased collagen synthesis
7
Q
LA
side effects
A
- CNS
- Cardiovascular
- Allergic
- Type A reactions
- Type B reactions
- Contraindications
8
Q
corticosteroids
side effects
local
A
- Post injection flare, transient post injection pain 12-24 hours
- subcutaneous fat atrophy
- skin depigmentation (use hydrocortisone)
- infection (1:14.000-50.000) (complication of procedure)
- poor technique
- adjacent infections
- haematogenous spread
- previous trauma
- contaminated
- Tendon weakening/rupture
- steroid atrophathy
- more from oral steroids
9
Q
A
10
Q
corticosteroids side effects systemic
A
- Flushing
- Impaired diabetic control
- Mood changes
- Menstrual disturbance
With repeated high doses:
- immunosuppression
- Hypothalamic-pituitary-adrenal axis(HPA-axis) suppression
- Iatrogenic Cushing´s syndrome
Allergic reactions & anaphylaxis (more with LA)
11
Q
Routes of elimination
A
Renal - mainly for smaller molecules
- most common route
- usually simple filtration
- more reabsorption from tubules if lipid soluble
- some drugs actively excreted by tubules
- effects of age - decreased renal function (>65)
Biliary - mainly larger molecules
- Concentrated in bile => bowel
- may be reabsorbed - entero hepatic circulation
Other routes
- lungs
- sweat
- tears
12
Q
LA Indications
A
Usually used in combination with steroid in MSM
- to give pain relief during and after an injection
- to increase volume of injection
- to distribute steroid
- maybe distension effect
diagnostic use
- re-examine after injection to see if signs reduced or abolished
13
Q
Corticosteroid indications
A
- Arthritis - especially inflammatory
- Capsulitis
- Bursitis
- Tenosynovitis
- Tendinosis
- mechanism of action:
- element of low grade inflammation
- pain relief - allows more normal use and other therapies
- collagen effects
- Trigger finger
- Tendinosis