Local Anesthesia,Indications And Contra-Indications Muhammad Wasif Haq Third Prof B.ds

Definition: “Local anesthetics are drugs that block sensory and motor nerve conduction to produce temporary loss of sensation without loss of consciousness. Local anesthetics are readily absorbed through mucous membranes and damaged skin”.

Classification: Local Anesthetics can be classified as: Esters (a. Long acting {Tetracaine}, b.Short acting {Procaine}, c.Surface acting {Benzocaine,cocaine) Ethers {Pramoxine} Alcohol {Benzyl Alcohol, Ethyl Alcohol} Amides (a.Long acting {Bupivacaine,Ropivacaine},b.Medium acting {Lidocaine,Prilocaine} Ketones {Dyclonine} Phenitidine Derivatives {Phenacine}

Composition: 2% solution of Lignocaine would contain: 20 mg Lignocaine HCl (main active agent) 6 mg NaCl (vehicle) 0.012 mg Adrenaline HCl (vasoconstrictor) 1 mg Methyl Paraben (preservative) 0.5 mg Sodium Metabisulphite (reducing agent) NaOH (to adjust PH)

Mode Of Dispensation Local anesthesia may be available as: Syringe form 2% viscous gel 5% ointment 10% liquid spray

Mode Of Action

Selection Of Local Anesthetic The choice of local anesthetic depends on: Duration of drug action (short=20 min, Intermediate=1-1.5 Hrs, Long=2-4 Hrs) Effectiveness at the administration site Potential for toxicity

Properties Of Ideal Anesthetic Potent Reversible block High therapeutic index Lack of irritation Rapid onset Duration of onset Adequate shelf life Penetration of mucous membranes

Indications For Local Anesthesia Any surgical pressure that can be anticipated to be painful for the patient requires local anesthesia. Following are few indications: Extraction of teeth Apicetomy Gingivectomy Periodontal surgery Pulpectomy,Pulpotomy Alveloplasty Bone grafting Implants

\ Indications For Local Anesthesia Gingivoplasty Treatment of jaw fracture (reduction and wiring) Replacement of avulsed tooth Dental cyst Removal of tumors Pericoronitis Removal of odontomes Stitching and muco-periosteal flapping.

Contraindications Acute infection/Inflammation at the site of puncture. Avoid blocking Inferior dental nerve in patients with infections in floor of mouth or retromolar areas. Haemphilia,Christmas disease,Von Willebrand factor disease. Hypersensitivity to Amide type of local anesthetic,sunscreens or sulfa drugs Strokes Adam syndrome Wolf Parkinson syndrome

Contraindications Severe degree of S.A, A.V. block Severe hypertension Spinal deformities and neurological disorders Liver diseases. Special precaution in elderly with liver and renal disorders.

Safety in cardiac patients and pregnancy? Cardiac patients may experience nausea,tachycardia,palpitations,restlessness,attacks of anxiety and increased tendency towards ventricular fibrillation. Alternatively plain local anesthesia or Felypressin can be used in place of Epinephrine. However Felypressin is not as effective vasoconstrictor as Epinephrine Possess mild oxytocic activity, may cause pre-mature labor Hence patiens with Ischemic cardiac diseases shall not receive more than 8.8 ml of 1:200,000 solution in one sitting.

Safety in cardiac patients and pregnancy? Use in pregnancy is not contra-indicated. However procedure should be delayed till termination of pregnancy. If very necessary, perform necessary procedure at minimum dose.

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