Local anesthesia ppt Introduction action

Local anesthesia

1. LOCAL ANESTHESIA L EYA JOY.K.J. 2018 BATCH THIRD YEAR BDS ROLL NO:34

2. CONTENTS INTRODUCTION DEFINITION CLASSIFICATION MECHANISM OF ACTION COMPOSITION INDICATION REFERENCE

3. INTRODUCTION Pain control is an integral aspect of modern dentistry. Pain is defined as an unpleasant sensational experience initiated by noxious stimulus and transmitted over a specialised neural network to CNS, where it is interpreted as unpleasant pain sensation. Local anesthetics produces a loss of sensation without inducing loss of consciousness. Many methods are used to induce local anesthesia . 1.Mechanical trauma 2.Low temperature . 3.Anoxia . 4.Chemical irritants etc

4. DEFINITION Local Anesthesia has been defined as loss of sensation in a circumscribed area of the body caused by depression of excitation in nerve endings or inhibition of the conduction process in peripheral nerves. Their action is completely reversible.

5. CLASSIFICATION LOCAL ANESTHETICS I NJECTABLE SURFACE 1. Short acting eg:procaine,chlorprocaine 2.Intermediate acting eg:lignocaine,prilocaine 3.Long acting eg:tetracaine,bupivacaine E g:Lignocaine,cocaine,tetracaine

6. MECHANISM OF ACTION Local anesthetics prevent the generation and conduction of nerve impulses. The primary mechanism of action is blockade of voltage gated sodium channels. LIGNOCAINE Bind s voltage gated sodium channels Blocks sodium ion entry into the cells Raises the threshold for excitation diffuses through the cell membrane

7. No generation and conduction of action potential Local anesthesia

8. COMPOSITION Local anesthetic agent : Lignocaine hydrochloride-2%(2 0 mg/ml) Reducing agent : Sodium metabisulphite-0.5mg Preservative : Methylparaben-0.1%(1mg) Diluting agent : Distilled water Fungicide : Thymol(0.4mg) Isotonic solution : Sodium chloride or Ringer's solution(6mg)-0.29 ml Vasoconstrictor : Adrenaline 1:80,000(0.012 mg) To adjust pH : Sodium hydroxide Nitrogen bubble : 1- 2 mm in diameter and is present to prevent oxygen from being trapped in the cartridge and potentially destroying the vasopressor

9. INDICATIONS Local anesthetics can be used alone or in combination with other types of anesthetic agents such as spinal or epidural anesthetics. LA is given to reduce stress associated with surgery and to provide pain relief after surgery. More commonly it is used for pain caused by hemorrhoids,fissures,insect bites and minor burns Indicated for vaginal ,rectal,and otological examinations, cystoscopy and catheterization Most frequent use :Regional anesthesia Treatment of intractable cough

10. TECHNIQUES OF LOCAL ANESTHSIA 1.SURFACE ANESTHESIA Anesthesia is entirely superficial and does not extend to submucosal structure. It is used for : tonometry, surgery, preoperative preparation of eye. nasal lesions tonsillectomy endoscopies

11. 2. INFILTRATION ANESTHESIA: Injection of a local anesthetic solution directly into the tissue can be : Superficial Into deeper structures It is used for: Minor procedures like incisions Drainage of abscess Excision 3 .FIELD BLOCK Subcutaneous injection of a LA solution proximal to the site to be anesthetized, interrupts nerve transmission in the region distal to the injection. Site such as foramen, scalp, anterior abdominal wall and lower extremity are used for field block.

12. 4. NERVE BLOCK Injection of a solution of LA around individual peripheral nerves or nerve plexus produces larger areas of anesthesia with smaller amount of drug. It is used for: Blocks of brachial plexus Intercostal nerve block Cervical plexus block Radial and ulnar nerve block 5. SPINAL ANESTHESIA LA solution is injected into subarachnoid space between L2-L3 or L3-L4 below the lower end of the spinal cord It is used for: Surgical procedures on lower limb, pelvis, lower abdomen Obstetric procedures

13. 6. EPIDURAL ANESTHESIA: LA is injected into the spinal extradural space. It is used for: Postoperative pain Terminal cancer pain 7. INTRAVENOUS REGIONAL ANESTHESIA: Useful for rapid anesthetization of an extremity. A rubber bandage is used to force the blood out of the limb(veins) and a tourniquet is applied to prevent the re-entry of blood. Onset of anesthesia is 2 minutes. It is used for: Used on the upper limb, legs and thighs.

14. REFERENCE PHARMACOLOGY FOR DENTAL AND ALLIED HEALTH SCIENCE - PADMAJA UDAYKUMAR (4TH EDITION) HANDBOOK OF LOCAL ANESTHESIA - STANLEY F. MALAMED (6TH EDITION) TEXTBOOK OF ORAL AND MAXILLOFACIAL SURGERY - NEELIMA ANIL MALIK (4TH EDITION)