This slides are useful for Ayurvedic Graduate students. It will give basic information regarding local anaesthesis

1. Dr Ardra B. Thorat
Assistant professor
Dept. of Shalyatantra, YAC. Kodoli

2. It is used to prevent the perception of pain
by blocking its different pathways such as
 Peripheral nerve fibers
 Nerves
 Plexus
 Ganglion
 Anterior / posterior nerve roots at spinal level

3. Advantages
 The patient remain conscious and still does not feel
pain
 No pre anesthetic preparation of the patient required
 Complications and unwanted effect of GA are avoided
 Does not required hospitalization
 Blood less field can be produced

4. Disadvantages
 Not good for uncooperative patients
 Ideal surgical condition not produced
 Hypersensitivity reaction
 May cause nerve injury
 Can not be used in infective area

5. Classification
 On basis of chemical structure
Aminoesterase Aminoamides
Procain Lignocain
Chloroprocain Mepivacain
Tetracain Prilocain
Benzocain Bupivacain
Cocain Etidocain
Ropivacain

6. Based on duration of action
Short duration low potency
 Chloroprocain
 Procain
Intermediate duration, intermediate potency
 Lignocain
 Mepivacain
 Prilocain
 Cocain

7. Long duration high potency
 Bupivacain
 Levobupivacain
 Tetracain
 Etidocain
 Dibucain
 Ropivacain

8. Mechanism of action
 Drug in dissociated (non ionized ) form penetrates the
axonal membrane and inside it gets dissociated
(ionized). This ionized form binds to receptor situated
in Na channel & blocks the channel, thus prevents
depolarization and hence action potential

9. General consideration
 Potency – correlates with lipid solubility. Cm is the
minimum conc. Of local anaesthesia that will block
nerve impulse conduction
 Onset of action- sequence of block in functional
term is autonomic sensory motor
sequence of recovery is in reverse order
motor sensory autonomic
 Among sensory fibers sequence of blockage is
temperature (cold hot) pain touch
deep pressure proprioception

10. Methods of LA
 Infiltration- local anaesthetic is infiltrated at operation site
 Topical-(surface anaesthesia)-
1. for skin= EMLA cream is used which is mixture of prilocain
5% +lignocain5% in equal amaunts
2. Xylocain spray 4%- at mucous membrane of mouth, pharynx,
larynx
3. Xylocain jelly 2%- catheterization, proctoscopy
4. Cocain drops & tetracain ointment
 Nerve block-drug is injected around the nerve supplying the
operation site
 Field block
 Root block
 Regional intravenous anaesthesia (Beir’s block)

11. Drugs and preparation
1. Xylocain
a. Plane 1%, 2%
b. With adrenalin 1%, 2%

12. Lignocaine(Xylocain,Lidocain)
 it is the most commonly used LA
Conc. Used
1. Nerve blocks- 1-2%
2. Urethral procedures (as jelly)- 2%
3. Surface (topical) analgesia- 4% & 10%
4. Spinal- 5%
5. Epidural- 1-2%
6. Intravenous regional analgesia- 0.5%
7. Infiltration block- 1-2%

13. Metabolism
 Metabolism in liver
 Excreted by Kidney
 T1/2 – 1.6 hrs
Duration of effect
 Without adrenalin - 45 to 60 minutes
 With adrenalin - 2-3 hours
Maximum safe dose –
Without adrenalin -4.5 mg /Kg (maximum 300mg)
With adrenalin =7mg /Kg (maximum 500mg)

14. Other uses
 Used for treating ventricular tachycardia