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Local anaesthesia /certified fixed orthodontic courses by Indian dental academy
Local anaesthesia /certified fixed orthodontic courses by Indian dental academy
Local anaesthesia /certified fixed orthodontic courses by Indian dental academy
Local anaesthesia /certified fixed orthodontic courses by Indian dental academy
Local anaesthesia /certified fixed orthodontic courses by Indian dental academy
Local anaesthesia /certified fixed orthodontic courses by Indian dental academy
Local anaesthesia /certified fixed orthodontic courses by Indian dental academy
Local anaesthesia /certified fixed orthodontic courses by Indian dental academy
Local anaesthesia /certified fixed orthodontic courses by Indian dental academy
Local anaesthesia /certified fixed orthodontic courses by Indian dental academy
Local anaesthesia /certified fixed orthodontic courses by Indian dental academy
Local anaesthesia /certified fixed orthodontic courses by Indian dental academy
Local anaesthesia /certified fixed orthodontic courses by Indian dental academy
Local anaesthesia /certified fixed orthodontic courses by Indian dental academy
Local anaesthesia /certified fixed orthodontic courses by Indian dental academy
Local anaesthesia /certified fixed orthodontic courses by Indian dental academy
Local anaesthesia /certified fixed orthodontic courses by Indian dental academy
Local anaesthesia /certified fixed orthodontic courses by Indian dental academy
Local anaesthesia /certified fixed orthodontic courses by Indian dental academy
Local anaesthesia /certified fixed orthodontic courses by Indian dental academy
Local anaesthesia /certified fixed orthodontic courses by Indian dental academy
Local anaesthesia /certified fixed orthodontic courses by Indian dental academy
Local anaesthesia /certified fixed orthodontic courses by Indian dental academy
Local anaesthesia /certified fixed orthodontic courses by Indian dental academy
Local anaesthesia /certified fixed orthodontic courses by Indian dental academy
Local anaesthesia /certified fixed orthodontic courses by Indian dental academy
Local anaesthesia /certified fixed orthodontic courses by Indian dental academy
Local anaesthesia /certified fixed orthodontic courses by Indian dental academy
Local anaesthesia /certified fixed orthodontic courses by Indian dental academy
Local anaesthesia /certified fixed orthodontic courses by Indian dental academy
Local anaesthesia /certified fixed orthodontic courses by Indian dental academy
Local anaesthesia /certified fixed orthodontic courses by Indian dental academy
Local anaesthesia /certified fixed orthodontic courses by Indian dental academy
Local anaesthesia /certified fixed orthodontic courses by Indian dental academy
Local anaesthesia /certified fixed orthodontic courses by Indian dental academy
Local anaesthesia /certified fixed orthodontic courses by Indian dental academy
Local anaesthesia /certified fixed orthodontic courses by Indian dental academy
Local anaesthesia /certified fixed orthodontic courses by Indian dental academy
Local anaesthesia /certified fixed orthodontic courses by Indian dental academy
Local anaesthesia /certified fixed orthodontic courses by Indian dental academy
Local anaesthesia /certified fixed orthodontic courses by Indian dental academy
Local anaesthesia /certified fixed orthodontic courses by Indian dental academy
Local anaesthesia /certified fixed orthodontic courses by Indian dental academy
Local anaesthesia /certified fixed orthodontic courses by Indian dental academy
Local anaesthesia /certified fixed orthodontic courses by Indian dental academy
Local anaesthesia /certified fixed orthodontic courses by Indian dental academy
Local anaesthesia /certified fixed orthodontic courses by Indian dental academy
Local anaesthesia /certified fixed orthodontic courses by Indian dental academy
Local anaesthesia /certified fixed orthodontic courses by Indian dental academy
Local anaesthesia /certified fixed orthodontic courses by Indian dental academy
Local anaesthesia /certified fixed orthodontic courses by Indian dental academy
Local anaesthesia /certified fixed orthodontic courses by Indian dental academy
Local anaesthesia /certified fixed orthodontic courses by Indian dental academy
Local anaesthesia /certified fixed orthodontic courses by Indian dental academy
Local anaesthesia /certified fixed orthodontic courses by Indian dental academy
Local anaesthesia /certified fixed orthodontic courses by Indian dental academy
Local anaesthesia /certified fixed orthodontic courses by Indian dental academy
Local anaesthesia /certified fixed orthodontic courses by Indian dental academy
Local anaesthesia /certified fixed orthodontic courses by Indian dental academy
Local anaesthesia /certified fixed orthodontic courses by Indian dental academy
Local anaesthesia /certified fixed orthodontic courses by Indian dental academy
Local anaesthesia /certified fixed orthodontic courses by Indian dental academy
Local anaesthesia /certified fixed orthodontic courses by Indian dental academy
Local anaesthesia /certified fixed orthodontic courses by Indian dental academy
Local anaesthesia /certified fixed orthodontic courses by Indian dental academy
Local anaesthesia /certified fixed orthodontic courses by Indian dental academy
Local anaesthesia /certified fixed orthodontic courses by Indian dental academy
Local anaesthesia /certified fixed orthodontic courses by Indian dental academy
Local anaesthesia /certified fixed orthodontic courses by Indian dental academy
Local anaesthesia /certified fixed orthodontic courses by Indian dental academy
Local anaesthesia /certified fixed orthodontic courses by Indian dental academy
Local anaesthesia /certified fixed orthodontic courses by Indian dental academy
Local anaesthesia /certified fixed orthodontic courses by Indian dental academy
Local anaesthesia /certified fixed orthodontic courses by Indian dental academy
Local anaesthesia /certified fixed orthodontic courses by Indian dental academy
Local anaesthesia /certified fixed orthodontic courses by Indian dental academy
Local anaesthesia /certified fixed orthodontic courses by Indian dental academy
Local anaesthesia /certified fixed orthodontic courses by Indian dental academy
Local anaesthesia /certified fixed orthodontic courses by Indian dental academy
Local anaesthesia /certified fixed orthodontic courses by Indian dental academy
Local anaesthesia /certified fixed orthodontic courses by Indian dental academy
Local anaesthesia /certified fixed orthodontic courses by Indian dental academy
Local anaesthesia /certified fixed orthodontic courses by Indian dental academy
Local anaesthesia /certified fixed orthodontic courses by Indian dental academy
Local anaesthesia /certified fixed orthodontic courses by Indian dental academy
Local anaesthesia /certified fixed orthodontic courses by Indian dental academy
Local anaesthesia /certified fixed orthodontic courses by Indian dental academy
Local anaesthesia /certified fixed orthodontic courses by Indian dental academy
Local anaesthesia /certified fixed orthodontic courses by Indian dental academy
Local anaesthesia /certified fixed orthodontic courses by Indian dental academy
Local anaesthesia /certified fixed orthodontic courses by Indian dental academy
Local anaesthesia /certified fixed orthodontic courses by Indian dental academy
Local anaesthesia /certified fixed orthodontic courses by Indian dental academy
Local anaesthesia /certified fixed orthodontic courses by Indian dental academy
Local anaesthesia /certified fixed orthodontic courses by Indian dental academy
Local anaesthesia /certified fixed orthodontic courses by Indian dental academy
Local anaesthesia /certified fixed orthodontic courses by Indian dental academy
Local anaesthesia /certified fixed orthodontic courses by Indian dental academy
Local anaesthesia /certified fixed orthodontic courses by Indian dental academy
Local anaesthesia /certified fixed orthodontic courses by Indian dental academy
Local anaesthesia /certified fixed orthodontic courses by Indian dental academy
Local anaesthesia /certified fixed orthodontic courses by Indian dental academy
Local anaesthesia /certified fixed orthodontic courses by Indian dental academy
Local anaesthesia /certified fixed orthodontic courses by Indian dental academy
Local anaesthesia /certified fixed orthodontic courses by Indian dental academy
Local anaesthesia /certified fixed orthodontic courses by Indian dental academy
Local anaesthesia /certified fixed orthodontic courses by Indian dental academy
Local anaesthesia /certified fixed orthodontic courses by Indian dental academy
Local anaesthesia /certified fixed orthodontic courses by Indian dental academy
Local anaesthesia /certified fixed orthodontic courses by Indian dental academy
Local anaesthesia /certified fixed orthodontic courses by Indian dental academy
Local anaesthesia /certified fixed orthodontic courses by Indian dental academy
Local anaesthesia /certified fixed orthodontic courses by Indian dental academy
Local anaesthesia /certified fixed orthodontic courses by Indian dental academy
Local anaesthesia /certified fixed orthodontic courses by Indian dental academy
Local anaesthesia /certified fixed orthodontic courses by Indian dental academy
Local anaesthesia /certified fixed orthodontic courses by Indian dental academy
Local anaesthesia /certified fixed orthodontic courses by Indian dental academy
Local anaesthesia /certified fixed orthodontic courses by Indian dental academy
Local anaesthesia /certified fixed orthodontic courses by Indian dental academy
Local anaesthesia /certified fixed orthodontic courses by Indian dental academy
Local anaesthesia /certified fixed orthodontic courses by Indian dental academy
Local anaesthesia /certified fixed orthodontic courses by Indian dental academy
Local anaesthesia /certified fixed orthodontic courses by Indian dental academy
Local anaesthesia /certified fixed orthodontic courses by Indian dental academy
Local anaesthesia /certified fixed orthodontic courses by Indian dental academy
Local anaesthesia /certified fixed orthodontic courses by Indian dental academy
Local anaesthesia /certified fixed orthodontic courses by Indian dental academy
Local anaesthesia /certified fixed orthodontic courses by Indian dental academy
Local anaesthesia /certified fixed orthodontic courses by Indian dental academy
Local anaesthesia /certified fixed orthodontic courses by Indian dental academy
Local anaesthesia /certified fixed orthodontic courses by Indian dental academy
Local anaesthesia /certified fixed orthodontic courses by Indian dental academy
Local anaesthesia /certified fixed orthodontic courses by Indian dental academy
Local anaesthesia /certified fixed orthodontic courses by Indian dental academy
Local anaesthesia /certified fixed orthodontic courses by Indian dental academy
Local anaesthesia /certified fixed orthodontic courses by Indian dental academy
Local anaesthesia /certified fixed orthodontic courses by Indian dental academy
Local anaesthesia /certified fixed orthodontic courses by Indian dental academy
Local anaesthesia /certified fixed orthodontic courses by Indian dental academy
Local anaesthesia /certified fixed orthodontic courses by Indian dental academy
Local anaesthesia /certified fixed orthodontic courses by Indian dental academy
Local anaesthesia /certified fixed orthodontic courses by Indian dental academy
Local anaesthesia /certified fixed orthodontic courses by Indian dental academy
Local anaesthesia /certified fixed orthodontic courses by Indian dental academy
Local anaesthesia /certified fixed orthodontic courses by Indian dental academy
Local anaesthesia /certified fixed orthodontic courses by Indian dental academy
Local anaesthesia /certified fixed orthodontic courses by Indian dental academy
Local anaesthesia /certified fixed orthodontic courses by Indian dental academy
Local anaesthesia /certified fixed orthodontic courses by Indian dental academy
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Local anaesthesia /certified fixed orthodontic courses by Indian dental academy

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The Indian Dental Academy is the Leader in continuing dental education , training dentists in all aspects of dentistry and offering a wide range of dental certified courses in different formats.

Indian dental academy provides dental crown & Bridge,rotary endodontics,fixed orthodontics,
Dental implants courses.for details pls visit www.indiandentalacademy.com ,or call
0091-9248678078

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  • 1. LOCAL ANAESTHESIA INDIAN DENTAL ACADEMY Leader in continuing dental education www.indiandentalacademy.com www.indiandentalacademy.com
  • 2. Contents History Armamentarium Definition &Classification Composition Different Agents , Vasoconstrictors Mechanism of Action Bio Transformation Systemic Action
  • 3. INTRODUCTION ‘No pain no gain’ Ancient time – dental treatment associated with pain Earliest pain relief – Coca shrub  mood elevator  Incas Cocoa shrub – foot hills of Andes Introduced by  Europeans to South America Cocaine
  • 4. 1855 – Gaedicke extracted alkaloid Erythroxylin 1860 – Dr. Scherzer  cocaine from this alkaloid 1844 – Francis Rynd (Dublin)   Acetate of morphine + Creosote  Skin incision  TGN treatment  First time liquid used - intradermally 1884 – marks birth of LA
  • 5. Sigmund Freud  Carl Koller  Cocaine for eye operation William Steward Halsted  Cocaine for inferior dental nerve 1886 – BDJ  William Alfred Hunt et al  Cocaine - dental anesthetic documented 1901 – E Mayers   Vasoconstrictor + cocaine
  • 6. 1905 13 lives claimed – addiction  A Einhorn & E Uhlfelder(Sweden)  Synthesized  Procaine hydrochloride  Procaine  sterilizable, non-additive, non-toxic  1943  N Lofgren(Sweden) Synthesized  Anilide called Lignocaine  Lignocaine – amide linked synthetic derivative 
  • 7. 1946 – Lignocaine introduced  Dental practice 1948 – Lignocaine ; published in BDJ – Lofgren Sweden – Birth place of newer LA agents  Bupivacaine  Ropivacaine
  • 8. Pain and pain control DEFINITION - It is defined as an unpleasant emotional experience usually initiated by a noxious stimulus and transmitted over a specific neural pathway to the central nervous system where it is interpreted as such.
  • 9. Methods of pain control. Accupuncture Analgesia - Originated-CHINA,between600BC to 200AD Hypnotism – Still employed—susceptible patients,  Time consuming, lasts for less time  Audio Analgesia – 1959 Gardner and licklider  Loud noise used to produce analgesia 
  • 10. Electric analgesia -Peripheral nerve- Direct electric current  Elos-1,powered by 18v battery- Siemens  Never more than 30 ma Analgesia by Cold air–  Inability to conduct AP at low tempr  Nondolar-French-60 lts/min-Cold air  Dis adv-Mucosa dry, Cotton stick to mucosa,ulcers-if not moistened.
  • 11. Armamentarium Syringe Breech loading, metallic cartridge-aspirating Advantage Disadvantage Visible cartridge Weight Aspiration- 1 hand Size-Too big Autoclavable Possibility of infection Rust resistance, Long lasting
  • 12. PISTON WITH HARPOON NEEDLE ADAPTOR FINGER GRIP SYRINGE BARREL THUMB RING
  • 13. Breech loading plastic cartridge-aspirating Advantage Disadvantage Light weight Size – Too big / small Cartridge visible Possibility of infection Rust resistance, Long lasting Repeated autoclaving – Plastic looses its properties Low cost
  • 14. PLASTIC REUSABLE SYRINGE
  • 15. Breech loading metallic cartridge-Self aspirating Advantage Disadvantage Cartridge visible Weight Autoclavable Possibility of infection Easier to aspirate Finger has to be moved from thumb ring to disc-Aspiration Piston is scored – Qty Known Takes time to accustom
  • 16. SELF ASPIRATING SYRINGE
  • 17. Pressure syringe -Advantage Disadvantage Measured dose Cost Overcomes tissue resistance Inject too rapidly -Possibility Non threatening – Cartridge protected
  • 18. PRESSURE SYRINGE
  • 19. WILCOX- JEWETT OBTUNDER
  • 20. Jet injectors Advantage Disadvantage Does not require – needle Inadequate – Pulpal / Regional block Very small volume – Delivered Patient disturbed by jolt of jet. Topical anesthesia-effective Cost PDL damage – common
  • 21. JET INJECTOR
  • 22. Disposable syringe Advantage Disadvantage Single use Does not accept – Dental cartridge Sterile-Till opened Aspiration – Difficult – 2 hands Light weight
  • 23. Needle  Type – Stainless steel – Disposable Platinum Iridium platinum Ruthenium platinum  Parts – Bevel Shank Hub-Leur lock, Friction grip.
  • 24. Gauge –23 (IM) – Length 23 mm 25 (D) – Length 36/26 mm - +ve asprn Blood – 100% 27 (D) – Length 27 mm - +ve asprn Blood – 87% 30 (D) – Length 22 mm - +ve asprn Blood – 2-5%
  • 25. Cartridge— Consists of - Cylindrical glass tube  Stopper  Aluminum cap  Diaphram
  • 26. Aluminum cap NECK Rubber diaphragm GLASS TUBE RUBBER PLUNGER
  • 27. Additional Armamentarium –  Topical antiseptic  Topical anesthetic  Cotton Gauge  Hemostat  Applicator Stick.
  • 28. Definition of L.A -It is defined as a transient loss of sensation to a painful or potentially painful stimulus, resulting from a reversible interruption of peripheral conduction along a specific neural pathway to its central integration and perception in the brain.
  • 29. Classification-Based on composition –  A) Natural – eg – cocaine.  B) synthetic nitrogenous compd – para amino benzoic acid-procaine, benzocaine. acetanilide quinoline -  lignocaine cinchocoline C) non Nitrogenous compounds benzyl alcohol  D) miscellaneous – clove oil , phenol .
  • 30. Based on intermediate group -Esters – Benzoic acid Amides – Para Amino benzoic Acid Articaine Butane Chloroprocaine Bupivacaine Cocaine Procaine Dibucaine Benzocaine Propoxycaine Lignocaine Hexylcaine Mepivacaine Tetracaine Prilocaine
  • 31. According to biological site and mode of action—  Class A Agents acting at receptor Biotoxin -eg site –external surface. tetrodotoxin  Class B Agents acting at receptor Quaternary amoniumsite- internal surface.. scorpion venom  Class C  Class D Agents acting at receptor Benzocaine independent physico chemical mechanism. Agents acting in combn Clinically useful agents –Lignocaine etc of receptor and independent mechanism.
  • 32. Injectables - Ultra short acting <80 min eg Lignocaine  Short acting 45-50 Min 2% ligno with 1:1 lakh VC  Surface -*Soluble - eg Cocaine Lignocaine *Insoluble- eg Benzocaine Medium acting 90-150 2% ligno with Vc or 4% prilocaine with 1:2 epin  Long acting > 180 5% Bupivacaine with 1:2 epin
  • 33. Composition-Local anesthetic drug –eg lignocaine . Vasopressor drug - eg adrenaline. Preservative - eg Sodium meta bi sulfide. Germicide – eg methyl paraben. For isotonicity – Normal Saline . Distilled water to equal the desired amount .
  • 34. Individual Agents -Lignocaine-- Classified under – Amide 2-diethylamino 2,6 acetoxylidide hcl  1943 – Nils Lofgrens- intro 1948(dentistry)  Metabolised- Liver by microsomal fixed function oxidases to monoethyl glycerine and xylidide  Excretion -<10% unchanged, >80%-metab  Vasodilaton ->Procaine, <Mepivacaine  Pka –7.9 , ph(plain)-6.5,ph(with Vc)5 –5.5,Onset of action 2-3 min,Anesthetic half life 1.6hrs,topical anesthetic -yes 
  • 35. CH3 C2H5 NH.CO.CH2.N CH3 LIGNOCAINE C2H5
  • 36. Recommended dose – 7mg/kg not>500mg with VC 4.4mg/kg not>300mg  For children with VC 3.2 mg/kg  Council for dental therapeutics- ADA 4.4mg/kg  It is non allergic available in three formulations Ligno2% with out Vc Ligno2% with VC 1:80,000 Ligno2% with VC 1:100,000  Adverse reactions- CNS stimulation then Depression,Overdose causes unconsciousness and respiratory arrest. 
  • 37.  Bupivacaine –Classified under amide  1-butyl 2,6 pipecoloxylidide  Toxicity <4 times – Lignocaine, Mepivacaine  Metabolism –Liver by Amidases  Excretion by kidney (16% unchanged)  Vasodilation- relatively significant  Pka-8.1,ph(plain)- 4.5-6, ph(vc)- 3-4.5 Onset of action –6-10 min,Anesthetic half life-2.7hrs,Dose 1.3mg/kg ,Maximum dose-not >40mg,Absolute maximum dose-
  • 38. CH3 NH.CO CH3 N C4H9 BUPIVACAINE
  • 39.  Available as 0.5% soln 1:2,00,000 (vc)  Indicaton- pulpal anesthesia->90- min. Full mouth recontruction. Extensive perio surgery. management of post op pain.  Duration –Pulpal- 90- 180 min Soft tissue-4-12 hrs  Contra indication- burning sensation at site of injecton, in children-anticipating self trauma .
  • 40.  Procaine- Classified under –Esters  2Diethylamino ethyl 4aminobenzoate hcl  Metabolised-in Plasma by plasma pseudocholine esterases  Excretion >2%unchanged, 90% -PABA,8% diethyl aminoethanol in urine.  Pka-9.1,High degree of vasodilation, 2% procaine 15-30min soft tissue LA no pulpal anesthesia , > incidence allergy, drug of choice for intra arterial injection and accidents.
  • 41.  Mepivacine- classified -amide type  1 Methyl 2,6 pipecoloxylidide hcl  Metabolism-microsomal fixed funcn oxidasea in liver.  Maximum dose 4.4 mg/kg , absolute max dose-300mg.  Excretion-1-10% unchanged urine.  Pka-7.6,Anesthetic half life-90min,  Mild vasodilator, 3% mepivacaine used in patients with vc contraindicaton. Low reported cases-allergy.over dose CNS stimulation followed by depression.
  • 42.  Articaine- classified- Amide 2 Carboxymethoxy 4 methylthiophene hcl  Metabolised- Liver  Excretion – Kidney 10% - unchanged.  Pka 7.8, Anesthetic half life-1.2-2 hrs,  Maximum dose – 1mg/kg , Absolute maximum dose – 500mg  first LA Agent with thiophene ring,little potential to diffuse through soft tissue.  Adverse reaction-methymoglobinemia-Rx by using methylene blue 1mg/kg. 
  • 43.  Etidocaine- classified –Amide  Metabolism –Liver  Excretion –urine- Kidney  Pka 7.7 ,Anesthetic half life-56 min.  Maximum dose 8mg /kg, Absolute max dose 400 mg  Employed mainly in epidural or caudal regional block.
  • 44. VASOCONSTRICTORS Added – to counteract vasodilation effect of injectable L.A  Decreases rate of absorption  Reduces the risk of overdose reaction  Increases duration of action  Reduces bleeding at the site
  • 45. CLASSIFICATION OF V.C Based on chemical stc  (Catechol nucleus) Catecholamines Non catecholamines Epinephrine Nor epinephrine Dopamine Amphetamine Meta amphetamine Based on mode of action Direct acting Epinephrine Nor epinephrine Indirect acting Mixed acting Amphetamine Tyramine Ephedrine
  • 46. EPINEPHRINE Proprietary Adrenaline name Mode of α1& β receptors action Systemic Systolic & 1) CVS Diastolic pressure FELYPRESSIN Octopressin Direct stimulation of vasculature No direct effect on Myocardium Heart rate Non-arrythmagenic Oxygen consumption High doses – impaired coronary flow Stroke volume
  • 47. 2) CNS CNS stimulation Adrenergic nerve – no effect 3) RS Bronchodilator 4) Vasculature α1 – vasoconstriction β 2 – vasodilation oxygen 5)Metabolism consumption blood sugar level Vasoconstriction – coronary blood vessels Anti-diuretic action Oxytocin like action – uterus
  • 48. 6) Clinical Allergy, hemostasis As vaso-constrictor in application L.A 7) Max 0.2 mg – healthy dose 0.04mg – CVS impaired 8) Side CVS & CNS symptoms effect Cerebral hemorrhage 0.04mg
  • 49. MECHANISM OF ACTION Resting membrane potential  Excitation of nerve  Stimulus – slow depolarization – electric potential less negative  increase in permeability to Na  Electric potential – critical level – firing / threshold potential  Rapid depolarization – reversal of electric potential  Reaches peak +35 mv - +40 mv  rapid depolarization (0.3msec)  Repolarize to RMP  -60 to –70mv (0.7msec)
  • 50. Conduction / propagation  Depolarization – 1segment – local current  affects RMP next segment  Current flow +ve  –ve; never backwards – prevented by previous unexcitable refractory segm. Spread Sequential depolarization - non myelinated  Saltatory conduction – myelinated – faster & energy efficient 
  • 51. Rate Non-myelinated 1.2m/s  Myelinated 14.8 – 120m/s  Site of action  Outer bimolecular lipoprotein layer in nerve membrane
  • 52. MODE OF ACTION Altering the basic RMP of nerve Altering the threshold potential Decreasing the rate of depolarization Prolonging rate of repolarization
  • 53. THEORIES OF ACTION OF L.A ACTEYLCHOLINE THEORY:  Involved in nerve conduction in addition to its role as a neurotransmitter at nerve synapses  No such evidence CALCIUM DISPLACEMENT THEORY:  L.A causes nerve block by displacement of Ca from some membrane site that controls entry of Na  Varying conc. Of Ca in nerve – not seen
  • 54. SURFACE CHARGE THEORY:  Action by binding to nerve membrane and changing its electric potential.   Cationic molecules aligned at membrane water interface – surface elec potn more positively charged - electric potn , threshold potn. Demerits- RMP not altered by LA. LA act on nerve channel rather than surface –cannot explain how uncharged LA molecule causes nerve blockage.
  • 55. Membrane expansion theory LA lipid soluble – enters nerve membr and changes configuration of membr. There by reduced space for sodium to enter and thus cause inhibition.  Explains how non ionised drug causes- blockade, nerve membrane do expand and become more fluid when exposed to LA .  No evidence to tell that the whole blockade is due to this phenomenon.
  • 56. Specific receptor theory—  LA act by binding to specific receptors- sodium channelon external/ axoplasmic surface.  Once it binds there is no permeability of sodium- no conduction. LA molecule replace calcium molecule at calcium gate – thus prevent sodium entry. This is by far the most accepted theory.
  • 57. Mechanism of action.  All LA are available as acid salt of weak bases.  Weak base(BNHOH) combined with acid (HCL) to give acid salt(BNHCL)& water.  In mucosa BNHCL dissociates into BNH and CL . Normal tissue PH 7.4 is necessary for conversion of acid salt to free base.  BNH which is hydrophilic further dissociates to BN and H. BN is now lipophilic.
  • 58.  Lipophilic BN diffuses through nerve membrane (lipid). Inside the nerve it combines with intrinsic H. (H in nerve formed by buffering action.)  Newly formed ionised BNH displaces calcium from the sodium channel receptor site to cause conduction blockade.
  • 59. LA Solution .
  • 60. Biotransformation. Esters- eg- Procainehydrolyzed to pseudo cholinesterase's Para amino benzoic acid Diethyl amino alcohol Excreted unchanged urine further transformed-urine Atypical cholinesterase's --- increase toxicity
  • 61. Amide eg lidocaine -Mono ethyl xylidide Glycine xylidide xylidide Xylidide Hydroxy xylidide. Excreted kidney . Significant renal diseases – contra
  • 62. Systemic action. CNS – Low levels – no action Toxic dose – tonic clonic convulsions Blood- 0.5-4.0 mg/ml-no complication 4.5-7.0 mg/ml-pre seizure sign/ symptom >7.5mg/ml-tonic clonic seizures. Anti convulsive property – As it causes depression of CNS. Seizure threshold- excitability nerve
  • 63. CVS Action on Heart  Electrical excitability of myocardium .  conduction rate  Tone of contraction. clinically effective level-1.8-5mg/ml –anti arrhythmic used in premature ventricular contractures , arrhythmias.
  • 64.  Action on vasculature- normal value no change. over dose- hypo tension.( myocardial contractility) Lethal dose- cardio vascular collapse ( myocardial contractility, massive peripheral vaso dilatation )
  • 65. Action on Respiratory system–  Normal levels- no over dose- bronchial muscles relaxation .  Over dose – Respiratory arrest due to CNS depression.
  • 66. Query Least toxic LA- 2 chlorprocaine. Most toxic LA- tetracaine- for topical-dicyclomine If allergic to LA –diphenhydramine- anti histamine + mild anesthetic For children - 2 chlorprocaine LA is added with bi carbonate in infections Allergy – delt in detail part II
  • 67. Ideal requirementsits action must be reversible  Must be non irritant and not produce any secondary irritation  Low degree of systemic toxicity  Must be potent enough  Have sufficient penetrating properties 
  • 68. LOCAL ANAESTHESIA part II www.indiandentalacademy.com
  • 69. Techniques of Injection Basic points Use a Sterile Sharp Needle  Check The flow of Solution  Determine Whether to Warm soln before use or not.  Position the patient  Dry the tissue/ wipe once.  Apply topical anesthetic
  • 70.  Topical antiseptic /optional  Communicate with patient apply firm hand rest  Inject few drops of soln, communicate with patient,  Advance to the target slowly ,aspirate , inject  Withdraw the needle slowly  Observe the patient & check for anesthetic symptoms
  • 71. Technique for Maxillary Block Supra periosteal injection:  Anaesthetize buccal soft tissue & hard tissue  Nerves anaesthetized – large terminal branches  Indication :  1 or 2 teeth need to be anaesthetized / small area
  • 72.  Contra-indication :    Infection Dense bone covering Target area :   Behind apices of tooth Landmarks :  Muco-buccal fold  Crown & root length
  • 73. Posterior Superior Alveolar Nerve Block  Area anaesthetized: Maxillary 3rd, 2nd & 1st molar (except mesio-buccal root of 1st molar  Bone & periodontium over these   Indication: Treatment of 2 or more molars required  Supra-periosteal injection – ineffective  Acute inflammation 
  • 74.  Contra-indication:   Pt with bleeding disorders Disadvantage: More of soft tissue landmarks used  2nd injection for 1st molar   Landmarks: Mucobuccal fold  Zygomatic process of maxilla  Infratemporal surface of maxilla  Anterior border and coronoid process of mandible  Tuberosity of maxilla 
  • 75.  Complications:  Hematoma –  Non visible - pterygoid plexus posteriorly  Visible – buccal aspect  Accidental mandibular Anaesthesia  Orbital contents – anaesthetized accidentally  Accidental - parotid gland  facial nerve affected
  • 76. Anterior superior alveolar nerve block  Areas anaesthetized Pulp of maxillary C.Is – Canine  Buccal periodontium, lower eyelid, lateral aspect of nose  Upper lip   Indications   More than 2 anterior teeth Contraindications Discreet treatment areas  Hemostasis of localized area – not adequately achieved 
  • 77.  Landmarks  Mucobuccal fold, infra-orbital notch, infra-orbital foramen 2 methods:  Intra-oral    Premolar approach Incisal approach Extra-oral
  • 78. Palatal Anaesthesia Pressure Anaesthesia Slow deposition  Small quantity  Effect only a very small area  Greater palatine nerve block  Areas anaesthetized Palatal soft tissue – posterior aspect  Palatal hard tissue 
  • 79.  Indication Surgical procedures posterior portion of hard palate  Palatal Anaesthesia in conjunction with posterior superior alveolar nerve block.   Landmarks Greater palatine foramen – junction of the maxillary alveolar process & palatine bone  Between the 2nd & 3rd molars – 1-1.5cms away from gingival margin 
  • 80. Nasopalatine nerve block  Areas anaesthetized   Anterior portion of Hard palate and over lying structures back to the bicuspid area. Indications Anterior palatal procedures supplementing infraorbital nerve blocks  Anaesthesia of nasal septum   Landmarks  Central incisor & incisive papilla
  • 81.  Complications    Hematoma Necrosis Technique  Single needle penetration  Multiple needle penetration Usually most discomforting block for patient – very painful
  • 82. Maxillary nerve block  Areas anaesthetized Pulpal Anaesthesia  Maxillary teeth – 1 side  Periodontium / soft tissue – 1 side   Indications Extensive oral / periodontal / endodontal procedures  Other regional nerve blocks not possible  Therapeutic procedure to diagnose neuralgias 
  • 83.  Contra-indications Pediatric patients  Infection / inflammation  Hemorrhage – anticipated  Greater palatine canal approach not possible – bony obstr.   Landmarks Mucobuccal fold distal to maxillary 2nd molar  Maxillary tuberosity  Zygomatic process  Greater palatine foramen 
  • 84.  Complications Hematoma  Penetration into orbit    Penetration into nasal cavity   Volume – displaces orbital structures, periorbital swelling, proptosis, 6th nr block – diplopia, transient loss of vision, optic nerve blocked, retrobulbar block / hemorrhage, opthalmoplegias (common) Patient complains – LA running down the throat – to prevent keep mouth wide open Technique High tuberosity approach  Greater palatine canal approach 
  • 85. Maxillary nerve block – Extra Oral  Areas anaesthetised Anterior temporal & zygomatic region  Lower eyelid  Side of nose  Anterior cheek  Upper lip  Maxillary teeth / alveolar bone & overlying structures – 1side  Hard & soft palate  Tonsils – parts of pharynx  Nasal septum – floor of nose 
  • 86.  Indications Extensive surgery – 1 half of maxilla  Others blocks not possible  Therapeutic purposes   Technique mid point of zygomatic process  Needle gently contact lateral pterygoid plate  Maximum length of 4.5cms directed slightly upward & forward   Note: In final position – internal maxillary artery – inferior to needle  Temporal vessels on either sides  Posteriorly foramen ovale with mandibular nerve & foramen spinosum with middle meningeal artery  Anteriorly pterygomaxillary fissure 
  • 87. Mandibular Nerve Blocks Inferior alveolar nerve block  Areas anaesthetised Mandibular teeth upto midline  Body of mandible  Inferior portion of ramus  Buccal periosteum & mucous membrane  Lingual soft tissue  Anterior 2/3rd of tongue   Indications Multiple mandibular teeth – procedures  Buccal / Lingual soft tissue anaesthesia 
  • 88.  Contraindications Infection / acute inflammation  Young children / mentally handicapped   Landmarks Coronoid notch  Pterygomandibular raphe  Occlusal plane of posterior mandibular teeth   Complication Hematoma  Trismus  Transient facial paralysis (parotid gland) 
  • 89.  Anatomical structures - final position  Superiorly – Inferior alveolar nerves & vessels  Insertion of medial pterygoid  Mylohyoid nerves & vessels   Anteriorly  – Deep part of parotid gland  Laterally – Lingual nerve  Internal pterygoid  Spehnomandibular ligament   Medially- ramus of mandible.
  • 90. Closed mouth/ Akinosis technq—  Area anesthetized   one half of mandible upto mid line including lingual tissue. Land markoccluding plane of the teeth.  Muco gingival junction maxillary teeth.  Antr border of ramus.   More popular now Land marks easy  One prick – mandibular, buccal, lingual n anesthetised.  Patient more comfortable. 
  • 91. Gow gates technique– 1973. deposit soln at neck of condyle  Area –all mandibular hard and soft tissue Upto mid line.  Land marks   antr border of ramus, tendon of temporalis, corner of mouth, inter tragic notch of ear and exter nal ear. Final position needle is just inferior to condyle.and insertion of lateral pterygoid. Gained popularity – single needle penetration, relies on soft tissue landmarks – differ from patient to patient
  • 92. Lingual nerve block –  Area anaesthetised – Anterior 2/3rd tongue, floor of mouth, lingual mucoperiosteum Only used singly to operate on tongue, floor of mouth  Buccinator / long buccal nerve block  Area anaesthetised –   Buccal mucosa & mandibular molar – mucoperiosteum Land marks  External oblique ridge, retromolar triangle
  • 93. Mental nerve block  Areas anaesthetised   Landmarks   Lower lip, mucous membrane – anterior to mental foramen Mandibular bicuspids Indications  Surgery of lower lip or mucous membrane
  • 94. Extra Oral Technique Mandibular nerve  Area anaesthetised Temporal region with auricle of ear & external auditory meatus  TMJ, salivary glands  Anterior 2/3rd of tongue  Mandible – hard & soft tissue – midline   Landmarks mid point of zygomatic arch  Zygomatic notch  Cornoid process of mandible  Lateral pterygoid plate 
  • 95.  Indications  When need to anaesthetise entire mandibular nerve  Infection / trauma – makes terminal anaestheisa not possible  Diagnostic / therapeutic The needle is pointed posteriorly & to a greater depth of 5 cms
  • 96. Mental & Incisive nerve block  Area anaesthetised   Mandibular hard & soft tissue – labial aspect with lower lip Landmarks Bicuspid teeth, lower ridge of body of mandible  Supra & infra orbital notch  Pupil of the eye  2 inch 22 gauge needle used & introduced slightly anteriorly & downwards
  • 97. Complications Definition  An anaesthetic complication may be defined as any deviation from the normal expected pattern during or after securing regional anaesthesia  2 types  Local  Systemic
  • 98. LOCAL COMPLICATIONS Needle breakage  Pain on injection  Burning on injection  Persistent anaesthesia or paresthesia  Trismus  Hematoma  Sloughing of the tissue / soft tissue injury  Facial nerve paralysis 
  • 99. SYSTEMIC COMPLICATIONS  Toxicity  Idiosyncracy  Allergy  Anaphylactoid reaction  Syncope
  • 100. Classification  Primary / secondary    Primary – caused & manifested at time of anaesthesia Secondary – manifested later Mild / severe  Mild – exhibit slight change from normal expected pattern - reverses itself without treatment  Severe – manifests itself – pronounced deviation - requires specific treatment
  • 101.  Transient / permanent  Transient – is one that is severe at occurrence – no residual effects  Permanent – residual effect; lasts for a life time even though it is mild Complications could be a combination of any of the above mentioned types Majority are either Primary Mild & Transient or Secondary Mild & Transient
  • 102. Complications  Attributed to solutions – toxicity, allergy, idiosyncrasy, anaphylactoid reaction, local irritation  Attributed to technique / needle – syncope, muscle trismus, pain, edema, hematoma
  • 103. Needle breakage Cause –  Unexpected movement – patient (if patient movement is opposite to path of needle insertion)  Usually at Hub – Magill forceps – hemostat used  If needle has penetrated soft tissue – not usually more than few mms deep – encased in scar tissue in few weeks – removed later on if necessary  Multiple used needle
  • 104. Prevention Correct gauge – 25 gauge  Long needles – prevent penetration till hub  Not to redirect when in tissue  Management Patient – not to move – hand in the mouth – mouth open  Fragment visible – remove it  Fragment not visible – inform patient – not necessary for intervention immediately – Radiograph suggested 
  • 105. Precautions  Avoid bony contact  Avoid heavy pressure  Avoid movement of needle and patient
  • 106. Pain on injection Causes – Careless injection technique  Multiple used needle  Rapid deposition  Problems –  Pain – patient anxiety – unexpected movements Prevention –     Proper technique – sharp needles Enter topical anaesthetics Inject slowly – solution sterilized Check temperature of solution
  • 107. Burning on injection Causes Due to pH of solution  5 (LA) – 3 (LA+VC)  Rapid injection  Contamination  Warm solution  Problems pH  disappears upon LA action – no residual sensitivity  Contaminated solution  other complications – trismus, edema, paraesthesia 
  • 108. Prevention  Slow injection – 1ml / minute  Cartridge stored at room temperature – away from containers with alcohol / other agents
  • 109. Persistent anaesthesia / paresthesia Causes Direct trauma to nerve – bevel of needle  LA solution containing neurotoxic substance – alcohol  Injection of wrong solution  Hemorrhage / infection – near to nerve  Problem Persistent anaesthesia – usually rare  Biting / thermal / chemical insult – without patient awareness  When lingual nerve is involved – taste impaired 
  • 110. Prevention Proper care & handling of dental cartridge  Adherence to injection protocol  Management Usually resolve in 8 weeks  Periodic recall & check up of patients  Persistence – consult neurosurgeon  LA – not to be injected in the same region 
  • 111. Trismus Definition  “difficulty in opening the jaws due to muscle spasm” Causes Trauma – muscle / blood vessel  Irritating solution – hemorrhage  LA have been known to have slight myotoxicity  Excessive volume – distension of tissues  Problems  Pain / hypomobility
  • 112. Prevention  Use of sharp, sterile, disposable needle  Aseptic technique  Practice atraumatic methods  Avoid repeated injections  Use minimum volume
  • 113. Management  Heat therapy   Analgesics   Aspirin, Codeine (30-60mg) Initial physiotherapy   Warm saline rinses, moist hot packs Thrice a day Antibiotic regime  Possibility of infection
  • 114. Hematoma Causes  Arterial & venous puncture – common in PSA & Inf Alv nerve blocks Problem Bruise – may / may not be visible extraorally  Complications – pain & trismus  Swelling & discolouration  Prevention Knowledge of normal anatomy – proper technique  Shorter needle – PSA, minimise the number of penetration 
  • 115. Management  Immediate – apply firm pressure  5-10minutes  Inf Alv Nr. Block – medial aspect of ramus  Infra orbital, Mental, Incisive block – directly over foramen  PSA – pressure on soft tissue with finger as posteriorly as tolerated by patient – medial superior direction Patient to be reviewed after 24 hours, advice analgesics, cold application upto 4-6 hours, heat application next day
  • 116. Infection Comparitively rare complication Instrument needle solution to be as aseptic as possible Area & operative hands – cleaned Avoid passing needle through infected area
  • 117. Edema Causes Trauma during injection  Infection, hemorrhage  Allergy (Angioedema)  Injection of irritating solution  Problems Pain & dysfunction  Airway obstruction 
  • 118. Prevention    Proper care & handling of armamentarium Atraumatic injection technique Complete medical evaluation prior to injection Management     Trauma – resolve in few days without therapy Hemorrhage – resolve slowly 7-14 days Allergy – life threatening, airway impairment – basic life support, call medical help, Epinephrine – 0.3mg, Antihistamine, Corticosteroids Total airway obstruction – Tracheostomy / Cricothyroidectomy
  • 119. Sloughing of tissue Causes Epithelial desquamation – topical anaesthesia – long time, heightened sensitivity to LA  Sterile abscess – secondary to prolonged ischemia – VC in LA  site – hard palate  Problems  Pain & infection Prevention Topical – for not more than 1-2 minutes  VC – minimal concentration in solution 
  • 120. Management  Symptomatic – pain – analgesia  Epithelial desquamation – resolve few days  Sterile abscess resolve  7-10 days
  • 121. Soft tissue injury Causes Trauma occurs – frequently mentally / physically challenged children  Primary cause – significantly longer duration of action  Problem Pain & swelling  Infection of soft tissue  Prevention Cotton roll between lip & teeth  Patient – guarded against eating / drinking 
  • 122. Facial nerve paralysis Cause  LA solution into parotid gland – usually while giving Inf Alv Nr. Block, Akinosis technique Problem Ipsilateral loss of motor control – Buccinator muscle  Inability to raise the corner of Mouth, close Eye lid  Prevention  Needle tip to contact bone, redirection of needle to be done only after complete withdrawl
  • 123. Management Reassure the patient  Eye patches to the affected – eye drops  Contact lenses if any – removed  Some post anaesthetic extra oral lesions – recurrent apthous stomatitis, herpes simplex seen in susceptible patient Mixture of Diphenhydramine, milk of magnesia – relief against ulcers
  • 124. Systemic complications Toxicity / toxic overdose Caused by overdose reaction – increased conc. In blood  Predisposing factors  Age – any age  Weight – greater the body weight greater is the amount of dose tolerated before overdose reaction  Sex – during pregnancy – renal function disturbed – females more affected at this time  Diseases – hepatic & renal dysfunction reduced breakdown  Congestive heart failure – less liver perfusion  Genetics – pseudocholinesterase deficient – toxicity - Ester LA 
  • 125.  Mental attitude and environment – pyschological attitude affects response to various stimuli – larger dose LA needed  Fearful patients – lower seizure threshold for LA  Drug factors – Vasoactivity – vasodilation – increase in blood  Concentration – greater concentration – greater risk  Dose smaller dose should always be preferred  Route of Administration – Intravascular – increased toxicity  Rate of injection – slower rate preferred  Vascularity of injection site – more vascular – greater absorption  Presence of Vasoconstrictor – with VC less absorption
  • 126.  Causes of toxicity – Biotransformation usually slow  Drug – slowly eliminated by kidney  Too large a total dose  Absorption from injection site - rapid  Accidental intra-vascular injection   Symptoms – CNS – cerebral cortical stimulation – talkative, restless, apprehensiveness, convulsions  Cerebral cortical depression – lethargy, sleepiness, unconsciousness  Medullary stimulation – increased B.P, Pulse rate, Respiration 
  • 127.  Medullary depression – mild fall in B.P– severe cases drops to 0 , Pulse , Respiration – similar effect Treatment Mild overdose reaction – slow onset reaction – > 5 mins administer Oxygen (prevent acidosis), monitor vital signs, in case of convulsions – anti-convulsants  Slower onset - >15 mins – same procedure  Severe overdose reaction – rapid onset – 1 minute – unconsciousness with or without convulsion, patient in supine position, convulsions – protect hand, leg, tongue, BLS, administer anti-convulsant ----------- post seizure – CNS depression usually present 
  • 128. Idiosyncrasy Any reaction neither toxic nor allergic Common cause – some underlying pathology / psychological Pyschotherapy may be helpful Treatment – symptomatic
  • 129. Syncope Anxiety – increased blood supply to muscles, sitting position 2mm Hg, less pressure – cerebral arteries Clinically light headedness, dizziness, tachycardia & palpitation – may further lead to Unconsciousness Treatment – discontinue procedure, supine position, deep breathing, BLS
  • 130. Allergy 1 % of all reaction in, LA is allergy Predisposing factors Hyper sensitivity to ester more common-procaine  Most of patients allergic to methyl paraben  Recently allergy to sodium meta bi sulfide is also increasing Precautions--Ho of allergy to be recorded Ho any asthmatic attack to be noted. Always better to test the patient for allergy before treatment. 
  • 131.  Consultation and allergy testing    Refer doubtful cases for allergic skin test – sub cutaneous test most sensitive. Informed consent that includes cardiac arest end death to be included. Signs and symptoms of allergy.  Dermatological------ urticaria –wheal and smooth elevated patch seen, ------angio oedema—localised swelling – face hands, common  Respiratory– broncho spasm, respiratory distress,  dysnea, wheezing, flushing, tachycardia etc.
  • 132.  Laryngeal edema – type of angio neurotic oedema- life threating. Edema upper air way – laryngeal edema  Lower air way affect broncioles- small.   Management  `skin reactions     Delayed – non life threatening - oral histramine blockers- 50 mg diphenhidramine Immediate reaction—with conjunctivites rhinitis- vigerous managemennt. 0.3 mg epinephrine. IM 50 mg diphenhydramine Im medical help summoned.
  • 133. Observe patient for minimum of 60 min  Oral histamine blockers for 5 days.  Respiratory reaction –  patient in comfortable position.  administer - oxygen  Admn epinephrine- bronchodilator  Observe for 60 min , advise anti histamines to prevent relapse.   Laryngeal edemaPatient position ,oxygen, broncho dilator, oral anti histamines.  If condition not improving cricothyrotomy - achieve patent air way if necessary give artificial ventilation. 
  • 134. Patient with confirmed allergy status if patient allergic to any one type of anesthetic ester / amide use the other.  Use histamine blocker like diphenhydramine as anesthetic.  General anesthesia  alternative method of pain control –  electric anesthesia / hypnosis.

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