LOCAL ANESTHESIA COMPLICATIONS & ITS

MANAGEMENT

BY-DR.ABDULRAZAKPOSTGRADUATE ORAL SURGERY

B.ID.S.,BANGALORE

A number of potential complications are associated with administration of local anesthetics they divided into those occuring locally & those that are systemic

Local complicationsThis includeNeedle BreakagePersistent Anestheisa or ParathesiaFacial Nerve ParalysisTrismusSoft Tissus InjuryHematomaPain on InjectionInfectionEdemaSloughing of TissuesPostanesthetic Intraoral Lesions

Needle BreakageIncidence of needle breakage & retention of the needle has become extremely low with the use of disposable needles but reports of needle breakage still appear despite of the fact that it can be prevented

CausesCauses for needle breakage areWeakening of the dental needle by bending it before insertionSudden movement by the patient as the needle penetrates the muscle or periosteumUse of smaller needle are more likely to break than larger needleNeedles prove to be defective in manufacture

ProblemsNo significant problem is associated with needle breakageIf the needle is visible it can be retrieved without any surgical intervention by using a hemostatIf the needle is within the soft tissue & is not visible is left in place as localised or systemic infection associated by such needles are extremely rareMore recently, removal of needle has been considered warranted primarily because of patient fear of migration & because of legal consideration

PreventionUse of larger needles for techniques requiring greater soft tissue penetration ,25 gauge needleUse of long needle for penetration of greater soft tissue depthNever insert the needle upto its hub as it is the weakest pointNever redirect the needle once it is inserted into tissues. Withdraw the needle completely before redirecting

ManagementWhen a needle breaksa.Do not panicb.Instruct the patient not to move. Keep the patient mouth open with your hand or bite blockc.If fragment visible try to remove with a hemostat

If the needle not visiblea.Do not proceed with an incision or probingb.Calmly inform the patient & attempt to allay fearc.Note the incident on patient’s chartd.Refer patient to oral & maxillofacial surgeon for consultation

Immediate removal of needle is considered under following conditionsa.When the needle is superficial & easily located it can be removed by competent dental surgeonb.Despite superficial location removal is unsuccessful within a reasonable time it is prudent to abandon the attempt & allow the needle to remainc.Deeper location of needle fragment & difficult to locate should be permitted to remain without attempts to remove

Persistent Anesthesia or ParesthesiaParesthesia is defined as persistent anesthesia or altered sensation well beyond the expected duration of anesthesiaIn addition to the definition it should also include hyperesthesia & dysthesia in which patient experience pain & numbnessIt can persist for days, weeks, monthsParesthesia is disturbing & sometimes unpreventable & most frequent cause of dental malpractice litigationA patient’s clinical response includes sensation of numbness, swelling, tingling & itchingThere may be associated oral dysfunction including tongue biting, drooling, loss of taste & speech impiarment

CausesTrauma to the nerve sheath by needle during insertionIncidence of paresthesia correlates with the experience of the operatorInjecting local anesthetic solution contaminated with aloohol or sterilizing solution cause nerve irritation resulting in edema & pressure near nerveAlcohol is neurolytic & can produce long term trauma to the nerveHemorrhage in & around nerve sheath causes increase pressure on the nerveLocal anesthesia can itself contribute to paresthesia

ProblemsParestheia can lead to self-inflicted injuryBiting or thermal or chemical insult can occur without patient’s awarenessWhen the lingual nerve is involved it results in loss of tasteHyperesthesia ie increased sensitivity to noxious stimuli & Dysesthesia ie painful sensation to nonnoxious stimuli

PreventionStrict adherence to injection protcol Proper care & handling of dental cartridges

ManagementMost paresthesia resolve approximately within 8 weeksIf damage of the nerve is severe paresthesia will be permanent but very rareMost cases paresthesia will be minimal with patient retaining most sensory function

Sequence in managing the patient with paresthesiaReassure the patienta.Speak to the patient personallyb.Explain that paresthesia is not uncommon after local anesthetic administrationc.Arrange an appointment to examine the patientd.Record the incident on patient chart

Examine the patienta.Determine the degree & extent of paresthesiab.Explain to the patient that it normally persist for atleast 2 monthsc.Tincture of time is recommended medicine

Reschedule the patient for examination every 2 months as long as the sensory deficit persist

If sensory deficit still persist after 1 year consultation with neurologist is recommended

Dental treatment may continue but avoid administration of local anesthetic into the same region. Use alternate local anesthetic techniques

Facial Nerve ParalysisParalysis of some of the terminal branches of facial nerve occurs during Infraorbital Nerve blockIt usually occurs by accidental deposition of local anesthetic into deep lobe of parotid gland under which terminal branches of facial nerve arise

CausesTransient facial nerve paralysis is commonly caused by introduction of local anesthetic into the capsule of parotid glandDirecting the needle posteriorly during Inferior Alveolar Nerve block or overinsertion of needle during Vazirani Akonisi nerve block, will place the needle in the parotid gland & deposition of the solution at this position produces facial paralysisDuration of facial paralysis is equal to soft tissue anesthesia noted for that drug

ProblemsLoss of motor function to the muscles of facial expression is normally transitoryIt lasts for no more than several hours depending on local anesthetic formulation & volume & proximity to facial nerveDuring this time patient has paralysis of muscles & unable to use these musclesPrimary problem is cosmetic, face appaers lopsidedSecondary problem is that patient is unable to close one eyeWinking & blinking becomes impossible but the corneal reflex is intact which lubricates the eye with tears

PreventionCan be prevented by following protocol with inferior alveolar nerve & vazirani-akinosi blocksA needle tip should be in contact with bone before depositing solutionIn vazirani-akinosi block over-insertion of the needle,more than 25mm should be avoided

ManagementReassure the patient explaining that this is transient & last a few hours & will resolve without any residual affectContact lenses should be removedAn eye patch should be applied to the affected eye untill muscular functions return. If patient not willing for this,ask patient to manually close the lower eyelids periodicallyRecord the incident on patient’s chartAlthough there is no contraindication for reanesthetizing the patient to achieve mandibular anesthesia, it is better to forego further dental care at this appointment

Trismus It is defined as prolonged, tetanic spasm of the jaw muscles by which normal opening of the mouth is restrictedIt was originally used for tetanus, but as inability to open mouth is associated with many conditions, this term is currently used in restricted jaw movement regardless of etiologyTrismus can become one of the more chronic & complicated problems to manage

CausesTrauma to muscles or blood vessels in the infratemporal fossa is the most common etiological factorLocal anesthetic contaminated with alcohol or sterilizing solutions produce irritation to the muscles causing trismusLocal anesthetics have been demonstrated to have mycotoxic properties on skeletal muscles. They cause progressive necrosis of exposed muscle fibresHemorrhage is another cause of trismus. Large volume of blood can produce tissue irritation,leading to muscle dysfunctionLow grade infection can also cause trismusExcessive volume of local anesthetic solution can cause distention of tissues

ProblemsLimitation of movement associated with trismus is minorBut it is possible to develop more severe limitationIn acute phase pain is produced by hemorrhage, lead to muscle spasm & limitation of movementsIn chronic phase hypomobility develops with organization of the hematoma with subsequent fibrosis & scar contractureInfection can develop as consequence to increased pain, increased tissue reaction & scarring

PreventionTrismus is not always preventable but incidence can be reduce byUse of sharp,sterile,diposable needleProper care for & handle of dental local anesthetic cartridgeUse of aseptic technique. Discard contaminated needles immediatelyPractice of atraumatic insertion & injection techniquesAvoid of repeat injections & multiple insertions into the same areaUse of minimum effective volumes of local anestheitc

Management

Patient with mild pain & dyfunction with minimum difficulty in jaw openinga.Arrange an appointment for examinationb.Prescribe heat therapy by applying hot moist towels for 20 minutes every hourc.Warm saline rinse by a teaspoon of salt in 12-ounce glass of warm water held in mouth & spit outd.Prescribe analgesic for managing pain & inflammatione.Prescribe muscle relaxant for intial phase of muscle spasmf.Advise to inititate physiotheraphy by opening & closing mouth as well as lateral excursions of the mandibleg.Record the incident, finding & treatment on patient charth.Avoid dental treatment till symptoms resolvei.If urgent dental treatment is required , use of vazirani-akinosi mandibular nerve block provide relief of muscle spasm permitting opening of jawj.Patient usually resolve within 48-72 hours & treatment to be continued till free of symptomsk.If dysfunction persist beyond 48 hours possibility of infection should be considered & antibiotics should be prescribed for 7 full days

For severe pain & dysfuntion if no improvement seen within 2-3days without antibiotics & 5-7 days with antibiotics or ability to open mouth has become restricted, use of ultrasound or appliance should be consideredSurgical intervention may be considered in chronic cases

Soft Tissue InjurySelf-inflicted trauma to the lips & tongue is caused by patient inadvertent biting or chewing on these tissues while still anesthetized

CauseOccurs more frequently in young children & mentally or physically handicapped children or adultsPrimary cause is that the soft tissue anesthesia last longer than the pulpal anethesia & patient being dismissed while soft tissue numbness still present

ProblemTrauma to anesthetized tissue can lead to swelling & significant pain once the anesthetic affect wears offYoung children or handicapped individual may have difficulty in coping with the situation & result in behavioral problemsThere is possibility of infection in traumatized tissues

PreventionBy using local anesthetic agent of appropriate durationA cotton roll can be placed between the lips & teeth in young children to prevent it from bitingSecure the roll with dental floss wrapped around the teethWarn the patient & guardian against eating, drinking hot fluidsWarn against testing the anesthesia by biting the lips or tongueA self-adherent warning sticker stating “watch me, my lips & cheeks are numb” can be placed on forehead of children

ManagementAnalgesics for painAntibiotics as necessaryLukewarm saline rinses to aid in decreasing the swellingPetroleum or other lubricant to cover the lip lesion

HematomaThe effusion of blood into extravascular space caused by nicking of blood vessels by needle during injection of local anestheticNicking of artery will produce hematoma which increases in size rapidly until treatment is initiatedNicking of vein may or may not produce hematoma

CauseTissue density surrounding the injured vessels determine the formation of hematomaDensity of tissue on hard palate & firm adherence to bone, hematome rarely develops on palateLarge hematoma are by either arterial or venous puncture following inferior alveolar nerve block or posterior superior alveolar nerve block. This is because tissue favors accumalation of large hematomasThe blood effuses out till the pressure external to blood vessels increases then internal pressure

ProblemHematoma produce bruise which may or may not be visible extrorallyPossible complication of hematoma include pain & trismusSwelling & discoloration subside with 7-14daysHematomas constitute inconvenience to patient & embarrassment to the operator

PreventionKnowledge of normal anatomyModify injection technique as dictated by patient’s anatomy Use of shorter needle for PSA nerve blockMinimize the number needle penetration into the tissueNever use a needle as a probe in the tissue

ManagementImmediate Managementa.Swelling becomes evident during or after local anesthetic injection, direct pressure should be applied for atleast 2 minutes on the site of bleedingb.For Interior Alveolar Nerve block pressure is applied on the medial aspect of the mandibular ramusc.For Infraorbital nerve block pressure is directly applied on the skin over the infrorbital foramend.For Mental nerve block pressure is applied on skin or mucous membrane over the mental foramene.For Buccal or Palatal nerve block place the pressure at the site of bleedingf.For Posterior Superior Alveolar Nerve block digital pressure is applied on the soft tissue in the mucobuccal fold as far distally as can be tolerated by the patient. Apply pressure in medial & superior direction. If available apply ice extraorally to increase the pressure on the site & help in consrtiction of vessel

Subsequent ManagementPatient can be dismissed when the bleeding stopsMake a note on patient dental chartAdvice patient about the possible soreness & trismusThere will be discoloration due extravascular blood elements which will subside within 7 to 14 daysIf soreness develops advice patient to take analgesicAvoid heat for 4-6 hours of incidentHeat can be applied from the next day acting as analgesia & vasodilation causing resorption of blood elementsIce may be applied on the day of incident,it acts as analgesic & vasoconstriction minimising the size of hematomsTime is most important in managing hematoma, with or without treatment resolve within 7-14 days

Pain on InjectionPain on injection can be best prevented by careful adherence to basic protocol of atraumatic injection

CausesCareless injection techniqueA needle can become dull after multiple injectionsRapid deposition of local anesthetic solutionNeedles with barbs caused by impaling the bone, may produce pain as they are withdrawn from tissue

ProblemPain on injection increases patient’s anxiety can result in sudden movement of patient & thus can lead to needle breakage

PreventionAdhere to proper techniques of injection Use of sharp needlesUse of topical anesthetic properly before needle insertionUse of sterile local anesthetic agentsInject slowlyBe certain that temperature of local anesthetic is correct

ManagementNo management is necessarySteps should be taken to prevent recurrence of pain associated with injection of local anesthetics

Burning on InjectionCausesBurning sensation occurring during local anesthetic injection is not uncommonPrimary cause is the pH of the solution, ie acidic pHRapid injection of local anesthetic solution especially in the densely adherent tissueContamination of local anesthetic by alcohol or sterilizing solutionSolution warmed to normal body temperature

ProblemBurning sensation is usually transientIt indicates irritation of tissues while injectingIf it is due to pH of the solution, it rapidly disappear once the anesthetic action starts & there is usually no residual sensitivity noted on termination of anesthetic actionWhen it occur as a result of rapid injection, using contaminated solution & using warmer solution, there is possibility of tissue damage with subsequent complication such as postanesthetic trismus, edema or possible paresthesia

PreventionIt is difficult but not impossible to eliminate burning sensation on injectionInjecting the solution very slowlyCartridge should be stored at room temperature in a container without alcohol or other sterilizing agents

ManagementIn most of the instances it is transient & do not lead to any prolonged tissue involvement, formal treatment is not usually indicatedIn few instance where discomfort, edema or paresthesia become evident, management of specific problem is indicated

InfectionInfection after local anesthetic administration has become extremely rare with introduction of sterile disposable needles

CausesMajor cause is contamination of needle before administration of anesthetic solutionContamination of the needle occurs when it touches with mucous membrane, this cannot be prevented or it is significantImproper handling of local anesthetic equipment & improper tissue preparation for injectionInjecting local anesthetic solution into an area of infection can push the bacteria to adjacent healthy tissue causing spread of infection

ProblemContamination of needle of solution can cause low grade infection when injected into deeper tissuesThis may lead to trismus if it is not recognised & proper treatment not initiated

PreventionUse of sterile disposable needlesProperly care for & handle needlesProperly care for & handle local anesthetic cartridgesa.Use a cartridge only onceb.Store cartridge aseptically in their original container, covered all timesc.Cleanse the diaphargm with a sterile disposable alcohol wipe immediately before useProperly prepare the tissues before penetration, dry them & apply topical antiseptic

ManagementLow-grade infection which is rare, seldomly recognised immediatelyPatient report postinjention pain & dysfunction 1 or more days after dental careThere are rarely any overt signs & symptoms of infectionImmediate treatment of trismus should be started

EdemaSwelling of tissues is not a syndrome but a clinical sign of presence of some disorder

CausesTrauma during injectionInfectionAllergy: Angioedema is a common response to ester local anesthetic agent in an allergic individuals, localized tissue swelling occurs as a result of vasodilation secondary to histamine releaseHemorrhageInjection of irritating solutions

ProblemEdema associated with anesthetic administration doesnot produce significant problems such as airway obstructionAnesthetic associated edema causes pain & dysfunction & embarrassment to the patientAngioneurotic edema caused by allergic reaction to topical agents can compromise airwayEdema of the tongue, pharynx, or larynx may develop & represent a potentially life treatening situation that requires vigorous management

PreventionProper care for & handle of local anesthetic armamentariumUse of atraumatic injection techniqueComplete an adequate medical evaluation of the patient before drug administration

ManagementWhen edema occurs due to traumatic injection or irritating solution it is of minimal degree & resolve in several daysIn all edema analgesics are necessaryAfter hemorrhage edema resolves within 7-14 daysIf signs of hemorrhage are evident, it should be managed in similar way as hematomaEdema caused by infection does not resolve spontaneously but become progressively more intensed if untreatedIf signs & symptoms of infection do not resolve in 3 days, anitbiotics should be prescribedAllergy induced edema is lifethreateningIf swelling develops in buccal mucosa causing no airway obstruction, can be managed by intramuscular & oral anti-histaminics

Edema occuring in the area compromising airway,treatment consists of followinga.If unconscious, patient is placed supineb.Maintain airway, breathing & circulationc.Definitive treatment should be startedd.Epinephrine is administered either IM or IV, every 10 mins untill respiration resolvese.Antihistaminics administered IM or IVf.Corticosteroids administered IM or IVg.Cricothyrotomy should be performed to relieve the airway obstruction

Sloughing of TissuesProlonged irritation or ischemia of gingival soft tissues lead to a number unpleasant complicationThese include epithelial desquamation & sterile abscess

CausesEpithelial DesquamationApplication of topical anesthetic for prolonged duration Heightened sensitivity of tissues to a local anestheticReaction in an area where a topical has been applied

Sterile AbscessSecondary to prolonged ischemia resulting from use of local anesthetic with vasoconstrictorUsually develops on hard palate

ProblemPain sometimes severe consequence to epithelial desquamation & sterile abscessThere is a remote possibility of infection

PreventionUse topical anesthesia as recommended, for 1-2 minutes to maximize the effect & minimize toxicityWhen using vasoconstrictor do not use highly concentrated solutions

ManagementNo formal management requiredReassure the patientManagement may be symptomatic, analgesia for pain & topical applied ointment to minimize irritationEpithelial desquamation resolve within a few days & sterile abscess run a course of 7-10 daysRecord data on patient chart

Postanesthetic Introral LesionsApproximately after 2 days of local anesthetic injection, patient report of ulceration in the mouth, primarily around the site of injectionPrimary initial symptom is pain & usually intense in nature

CauseRecurrent aphthous stomatitis or herpes simplex can occur after a local anesthetic administration or after a trauma to intraoral tissuesRecurrent apthous stomatitis most common mucosal disease, develop on gingival tissues that are not fixed to the underlying bone, eg. buccal mucosa.The cause of apthous stomatitis is poorly understood, unpreventable & treatment is symptomaticHerpes simplex is a viral infection, manifest as small bump occuring on the gingival tissues that fixed to the underlying bone, such as soft tissue of the hard palateTrauma to tissues by needle, local anesthetic solution, cotton swab or any other instrument may activate latent form disease process that was present in tissue before injection

ProblemPatient complains of acute sensitivity in the ulcerated areaMany consider that the tissue is infected as a result of local anesthetic injection, however the risk of secondary infection developing in this situation is minimal

PreventionUnfortunately there is no means of prevention of these intraoral lesions from developing in susceptible patientsExtraoral herpes simplex can be prevented or clinical manifestation can be minimized if treated in prodromal phaseThe prodrome phase consist of itching or burning at the site where virus is presentAntiviral agent such as acyclovir applied qid can affectively minimized acute phase

ManagementPrimary management is symptomaticReassure the patient that it is not caused by infection secondary to local anesthetic injection but an exacerbation of the situation that was already presentNo management is necessary if the pain is not severeTopical anesthetic solution may be applied as needed to the painful areasA mixture of equal volume of diphenhydramine & milk magnesia rinsed in mouth effectively coat the ulceration & provide relief from painUlcerations last for 7-10 days with or without treatmentMaintain records on patient chart

Systemic ComplicationsThis includesOverdose/ToxicityAllergy

Overdose/ ToxicityA drug overdose reaction has been defined as those clinical signs & symptoms that result from an overly high blood level of a drug in various target organs & tissuesFor an overdose reaction drug must first gain access to the circulatory system in quantities sufficient to produce adverse effects on various tissues of the bodyNormally a balance exist between the rate of drug being absorbed from the site of administration into the circulatory system & rate of drug being eliminated from circulatory system by redistribution & biotransformationWhen for some reason the degrading mechanisms are unable to handle the absorbed drugs, equilibrium is destroyed & a state of systemic toxicity develops

CausesToo large a dose of local anesthetic drugUnusually rapid absorption of the drug or intravascular injectionUnusually slow biotransformationSlow elimination or redistribution

Predisposing factorsPatient’s general physical condition at the time of injectionRapidity of injectionRoute of administration(eg. Inadvertent intravascular injection)Amount of the drug usedAge of the patient

The smallest dose of drug that is clinically effective should be administeredThe volume of the drug should be administered very slowly because speed of injection is a factor in a rapid absorption of drug & subsequent toxic reactionsThe more vascular the area more rapid will be the absorption of the drug & possible toxic reactions

Clinical ManisfestationClincal signs & symptoms of local anesthetic overdose develop when anesthetic blood level in an organ becomes high for that individualPrimary action of local anesthetic is depressant effect on all excitable membranesCentral Nervous System & Cardiovascular System are more susceptible

Effect on Central Nervous SystemCentral Nervous System is extremely sensitive to actions of local anestheticAs the cerebral blood level of the local anesthetic increases, clinical signs & symptoms are notedLocal anesthetic readily cross the blood brain barrier & produce CNS depression

At non-overdose levels of lidocaine, less than 5ug/ml there is no adverse effect on CNSSigns of CNS toxicity develops when cerebral blood level increases, greater than 4.5ug/mlThere is generalized cortical sensitivity such as talkativeness, agitation, irritation, slurred speech, sweating, vomittingTonic-clonic seizures generally occur at levels greater than 7.5ug/mlWith further increase in the blood level seizures terminate & a state of generalized CNS depression developsRespiratory depression & arrest are manifested

Effect on CardioVascular SystemCVS is less sensitive to the action of local anestheticAdverse CVS response develop much late after adverse CNS actions have appearedAt level of 1.8ug/ml to 5ug/ml local anesthetic can be used in the management of cardiac dysrhythmias as its primary action being depression of excitable membraneAt increased level 5ug-10ug/ml it leads to minor alteration on the electrocardiogram, myocardial depression, decrease cardiac output & peripheral vasodilationAbove 10ug/ml intensification of these effect occur- primarily massive peripheral vasodilation, marked reduction in myocardial contractility, severe bradycardia & possible cardiac arrest

ManagementManagement of local anesthetic overdose is based on severity of reactionIn most cases reaction is mild & transitory, requiring little or no specific treatmentIn some instances reaction may be severe & longer, requiring prompt therapy

Mild Overdose ReactionSigns & symptoms of mild overdose are retention of consciousness, talktiveness & agitation along with increased heart rate, blood pressure & respiratory rate developing between 5-10 mins of completion of anesthetic injection

Slow Onset greater than 5 minutesRapid absorption & too large dosePosition the conscious patient comfortablyAirway, Breathing & Circulation assesedDefinitive carea.Reassure the patientb.Administer oxygen via nasal cannula or nasal hoodc.Monitor & record vital signsd.Establish IV infusione.Permit the patient to recover as long as necessary

Slower Onset greater than 15minutesAbnormal biotransformation & renal dysfunctionPosition the patient comfortablyAirway, Breathing & Circulation assessedDefinitive Carea.Reassure the patientb.Administer oxygenc.Monitor vital signsd.Establish IV infusion & administer anticonvulsante.Seek medical assistancef.Examination including blood tests, hepatic & renal function testg.Do not allow the patient to leave alone, arrange for adult companionh.Determine the cause of reaction before proceeding with therapy

Severe Overdose Reaction

Rapid Onset within 1 minuteSigns & symptoms are unconsciousness with or without convulsionCause is intravascular injectionPosition the unconscious patient supine with legs slightly elevatedAirway, Breathing & Circulation assessed & maintainedDefinitve Carea.Protect the patient’s arms, legs & head. Remove tight clothing such as tie, collars & belts & remove pillow from headrestb.Immediately seek emergency medical assistancec.Conitune basic life support. Administer oxygend.Establish IV infusion & administer anticonvulsant if seizure do not stop with in 3 minutes. Diazepam 5mg/min or midazalom 1mg/min until seizure stops

Slow Onset 5-15 minutesPossible causes of severe reactions of slow onset are too large a total dose, rapid absorption, abnormal biotransformation & renal dysfunctionTerminate the dental treatment immdeiatelyPostion the patient comfortablyAirway, Breathing & Circulation assessed & maintainedDefinitve carea.Establish IV infusion & administer anitconvulsantb.Seek emergency medical assistancec.IM or IV administration of vasopressor for hypotensiond.Permit the patient to recover for as long as possible. Patient should be examined by physician before discharge

Epinephrine OverdosePrecipitating factorsEpinephrine used with local anesthetic in concentration 1:200,000 rarely causes overdose reaction at this concentrationEpinephrine overdose is more common after its use in retraction cord before impression for crown & bridge procedureCurrently cords contains 225.5ug of racemic epinephrine per inch of cordEpinephrine is readily absorbed through gingival epithelium & 64 to 94% of applied epinephrine is absorbed into the CVS

Clinical ManifestationsSigns - elevation of blood pressure, elevated heart rate, cardiac dysrhythmiasSymptoms – fear, anxiety, tenseness, restlessness, tremor, throbbing headache, perspiration, weakness, dizziness

ManagementAt most instances epinephrine overdose are of such short duration that little or no formal management is requiredOn occasion reaction may be prolonged that some management may be requiredImmediately terminate the procedureIf possible remove the source of epinephrine, this will lessen the release of endogenous epinephrine & norepinephrine from adrenal medullaEpinephrine impregnated cords should be removedPosition the patient comfortably ie semisitting or erect positionAirway, Breathing & Circulation is assessed & maintainedDefinitive Carea.Reassure the patient that signs & symptoms will subsideb.Monitor vital signs & administer oxygen. Blood pressure & heart rate should be checked every 5 minutesc.In apprehensive patient there is hyperventilation. Do not admister oxygen in case of hyperventilationd.Permit the patient to remain on the dental chair as long as necessary to recover. Do not discharge the patient if any doubt remains about ability of self-care

AllergyAllergy is a hypersensitive state, acquired through exposure to a particular allergen, re-exposure to which produces a heightened capacity to reactAllergic reaction cover a broad spectrum of clinical manifestations ranging from mild & delayed responses occurring as long as 48 hours after exposure to the allergen, to immediate & life-threatening reactions developing within seconds of exposure

Predisposing factorsAllergy to local anesthetic does occur but its incidence has been decreased dramatically with the introduction of amide anestheticsAllergic responses to local anesthetic include dermatitis, bronchospam & systemic anaphylaxis. Localized dermatological reaction most frequently occurAllergic reaction most commonly occurs with methylparaben,bacteriostatic agentParaben are included as bacteriostatic agents in all multiuse drugs, cosmetics & some foodAllergy to sodium bisulfite or metabisulfite is increasingBisulfites are anitoxidants, commonly sprayed onto fruits & vegetables to keep them appearing freshPersons allergic to bisulfite may develop severe response like bronchospasm

Topical Anestheitc Allegry Topical anesthetics possess a potential to induce allergy Most commonly used anesthetic for topical anesthesia are esters such as benzocaine & tetracaineThe incidenc of allergy to this group of anesthetic far exceed than that of amide local anestheticBecause benzocaine is not absorbed systemically, allergic reactions are limited to the site of applicationWhere as other topical anesthetics are absorbed systemically may either produce allergic response locally or systemically

Prevention Allergic incidence can be minimized by proper history taking regarding allergy to any drug,local anesthetic in particularQuestioning about the type of reaction occurredType of treatment given at time of allergic reaction

Clinical manisfestationDepending on the time elapsing between contact with the antigen & the onset of clinical manifestation, allergic reactions are classified as, immediate reactions & delayed reactionImmediate reaction, particular anaphylaxis is significant with many organs & tissues involvedThese include skin, cardiovascular system, respiratory system & gastrointestinal systemAnaphylaxis also may involve only one system causing localized allergy. Egs bronchospasm & urticaria

Signs & symptomsDermatological ReactionsMost common allergic reaction associated with local anesthetic is urticaria & angioedemaUrticaria is associated with wheals which are smooth elevated patches of skin. Intense itching is presentAngioedema is localized swelling. Skin colour & temperature are normal. Pain & itching are uncommonAngioedema most frequently involves face, hands, feet & genitalia but can involve lips, tongue, pharynx & larynxThey occur within 30-60 minutes of anesthetic application They are sole manifestation of allergic response & are normally not life threatening

Respiratory ReactionsRespiratory reactions occur solely or along with other systemic reactionsBronchospasm is classic respiratory allergic responseOther signs & symptoms are respiratory distress, dyspnea, wheezing, flushing, cyanosis, perspiration, tachycardia, use of accessory muscles

Laryngeal edemaLaryngeal edema is extension of angioedema to the larynx is swelling of the soft tissues surrounding vocal apparatusResults in subsequent airway obstructionLittle or no exchange of airway from lungsIt represent the effect of allergy on the upper airway

Generalized anaphylaxisThe most dramatic & acutely life threatening allergic reaction is generalized anaphylaxisClinical death can occur with in a few minutesTime to response is variable but reactions develops rapidly reaching peak in 5-3o minutesSigns & synptoms includea.Skin reactionsb.Smooth muscle spasm of gastrointestinal tract & respiratory tract bronchospasmc.Respiratory distressd.Cardiovascular collapse

In fatal anaphylaxis respiratory & cardiovascular reaction predominate & occur earlyIn rapidly developing reactions all signs & symptoms occur within every short span of time & may overlapWith prompt treatment the entire reaction can be terminated rapidlyHypotension & laryngeal edema may persist for hours to daysDeath may occur anytime during reaction, is secondary to laryngeal edema

ManagementSkin reactionsDelayed skin reactionsSigns & symptoms developing after 60 minutes or more after exposure, usually do not progress nor they life threateningPositions the patient comfortablyAirways, Breathing & Circulation are assessed as adequateDefinitive Carea.Oral anithistamine 50mg diphenhydramine or 10mg chlorpheniramineb.Patient should under observation in dental office for 1 hourc.Obtain medical consultation before discharge

Immediate skin reactionSigns & symptoms developing within 60 minutes require more vigorous treatment Position the patient comfortablyAirway, Breathing & Circulation assessed as adequateDefinitive Carea.Administer Epinephrine 0.3mg IM or SCb.Administer antihistamine IM 50mg diphenhydraminec.Obtain medical consultationd.Observe the patient for minimum of 60 minutese.Prescribe antihistamine for 3 days

Respiratory reactionsBronchospasmPosition the patient comfortably. Patient made to sit uprightAirway, Breathing & Circulation assessedDefinitive Carea.Terminate treatmentb.Administer oxygen by fullface mask, nasal hood or nasal cannulac.Administer epinephrine via aerosol inhalar or by IM/SC 0.3mgd.Observe for 60 minutes, if it reoccurs readminister epinephrine 0.3mg IMe.Administer antihistamine to minimize possibility of relapse. 50mg diphenhydramine IMf.Medical consultationg.Prescribe oral antihistamine & complete a thorough allergy evaluation

Laryngeal EdemaLaryngeal edema may be present when movement of air through patient’s nose or mouth cannot be heardWhen it is impossible to carry on artificial ventilation in the presence of a patent airwayPartial obstruction may lead to total obsrtuction accompanied by ominous sound of silencePatient losses consciousness from lack of oxygenPosition the unconscious patient supineAirway, Breathing & Circulation is assessed & maintainedDefinitive Carea.Administer epinephrine 0.3mg IM or SCb.Maintain airwayc.Additional drug management, antihistamine 50mg diphenhydramined.Corticosteroid IM or IV 100mge.Perform cricothyrotomy as a emergency procedure to secure a patent airway essential for survivalf.Once airway is establish administer oxygen g.Monitor vital signs

Generalized AnaphylaxisSign of allergy presentWhen signs & symptoms of allergy present such as urticaria, erythema, pruritus & wheezingPosition the unconscious patient supineAirway, Breathing & Circulation maintained Definitive Carea.Administer epinephrine IM. Subsequent injection is given after 10 minutes & when needed administered every 10-15 minutesb.Administer oxygenc.Monitor vital signsd.Additional drug therapy. Administration of antihistamine & corticosteroid both IM or IV

No signs of allergyIf a patient receiving local anesthetic loses consciousness & no signs of allergy are present, the differential diagnosis include psycogenic reaction, overdose reaction & allergic reaction involving only cardiovascular systemPosition the unconscious patient supineAirway, Breathing & Circulation assessed & maintainedDefinitive Carea.Terminate treatmentb.Administer oxygenc.Monitor vital signsd.Summon medical emergency servicese.Additional management include diagnosis the cause of unconsciousness. Appropiate drug therapy institutedf.In absence of sign & symptom, epinephrine & other drug therapy are not indicatedg.Any number of cause may be associated with loss of consciousness, eg, drug overdose, hypoglycemis, cerebrovascular accident, acute adtenal insufficiency or cardiopulmonary arresth.Continue basic life support until medical assistance arrives

ReferenceHandbook of LoacalAnesthesia by Stanley F. MalamedMonheim’s Local Anesthesia & Pain Control in Dental Practice