Assessment task 1

Question 1

commonly used local anesthetics

max doses

Answer 1

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

Question 2

commonly used

Answer 2

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

Question 4

LA actions

Answer 4

• 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

Question 6

Corticosteroids

actions

Answer 6

• 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

Question 7

LA

side effects

Answer 7

• CNS
• Cardiovascular
• Allergic
• Type A reactions
• Type B reactions
• Contraindications

Question 8

corticosteroids

side effects

local

Answer 8

• 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

Question 10

corticosteroids side effects systemic

Answer 10

• 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)

Question 11

Routes of elimination

Answer 11

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

Question 12

LA Indications

Answer 12

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

Question 13

Corticosteroid indications

Answer 13

• 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