systemic complications. drug actions all drugs produce multiple effects these effects are...

SYSTEMIC COMPLICATIONSSYSTEMIC COMPLICATIONS

Drug ActionsDrug Actions

All drugs produce multiple effectsAll drugs produce multiple effects

These effects are categorized as:These effects are categorized as:

DesiredDesired

OROR

UndesiredUndesired

General PrinciplesGeneral Principles

No drug exerts a single actionNo drug exerts a single action

No drug is non-toxicNo drug is non-toxic

Potential toxicity is user dependentPotential toxicity is user dependent

Adverse Drug ReactionsAdverse Drug Reactions

Direct extensions of usual effectsDirect extensions of usual effects

Side effectsSide effects

OverdoseOverdose

Local toxic effectsLocal toxic effects

Adverse Drug ReactionsAdverse Drug Reactions

Altered recipientAltered recipient

Disease processDisease process

Emotional disturbancesEmotional disturbances

Genetic aberrationsGenetic aberrations

IdiosyncracyIdiosyncracy

Adverse Drug ReactionsAdverse Drug Reactions

Allergic reactionAllergic reaction

Immediate - anaphylaxisImmediate - anaphylaxis

Delayed - contact dermatitis Delayed - contact dermatitis

OverdoseOverdose

Dose relatedDose related

Systemic distributionSystemic distribution

Extension of pharmalogic effectsExtension of pharmalogic effects

Selective CNS or CVS depressionSelective CNS or CVS depression

Allergic ReactionsAllergic Reactions

Not dose relatedNot dose related

May be systemic or localizedMay be systemic or localized

Unrelated to pharmacological effectsUnrelated to pharmacological effects

Exaggerated immune system responseExaggerated immune system response

Idiosyncracy ReactionIdiosyncracy Reaction

Unexplained by any known mechanism of the Unexplained by any known mechanism of the drug’s actiondrug’s action

Neither overdose nor allergic reactionNeither overdose nor allergic reaction

Unpredictable; treat symptomsUnpredictable; treat symptoms

Predisposition - OverdosePredisposition - Overdose

Patient factorsPatient factors

AgeAge

WeightWeight

SexSex

Medications Medications

Predisposition - OverdosePredisposition - Overdose

Patient factorsPatient factors

DiseaseDisease

GeneticsGenetics

Psychological attitudePsychological attitude

Predisposition - OverdosePredisposition - Overdose

Drug factorsDrug factors

VasoactivityVasoactivity

ConcentrationConcentration

DoseDose

Route of administrationRoute of administration

Predisposition - OverdosePredisposition - Overdose

Drug factorsDrug factors

Rate of injectionRate of injection

Vascularity of siteVascularity of site

VasoconstrictorsVasoconstrictors

Cause of Overdose LevelsCause of Overdose Levels

Total dose is too largeTotal dose is too large

Absorption is too rapidAbsorption is too rapid

Intravascular injectionIntravascular injection

Biotransformed too slowlyBiotransformed too slowly

Eliminated too slowlyEliminated too slowly

BiotransformationBiotransformation

Esters are hydrolyzed in the plasma and liver Esters are hydrolyzed in the plasma and liver by pseudocholinesterase into PABAby pseudocholinesterase into PABA

Amides are biotransformed by microsomal Amides are biotransformed by microsomal enzymes in liverenzymes in liver

EliminationElimination

Both esters and amides are eliminated through Both esters and amides are eliminated through kidney, some in unchanged form eg. kidney, some in unchanged form eg. (lidocaine - 10%)(lidocaine - 10%)

Prilocaine is eliminated by lungsPrilocaine is eliminated by lungs

Excessive DoseExcessive Dose

Maximum dose should be based on:Maximum dose should be based on:

AgeAge

Physical statusPhysical status

WeightWeight

Rapid AbsorptionRapid Absorption

Vasoconstrictors should be used unless Vasoconstrictors should be used unless specifically contraindicatedspecifically contraindicated

Intravascular InjectionIntravascular Injection

Occurrence varies with type of injection:Occurrence varies with type of injection:

Nerve BlockNerve Block % positive aspirate% positive aspirate

Inf. alveolar 11.7Inf. alveolar 11.7

Mental/Incisive 5.7Mental/Incisive 5.7

Post. sup. alv. 3.1Post. sup. alv. 3.1

Ant. sup. alv./ Buccal < 1Ant. sup. alv./ Buccal < 1

PreventionPrevention

Use aspirating syringeUse aspirating syringe

Use needle - 25 ga or largerUse needle - 25 ga or larger

Aspirate in 2 planesAspirate in 2 planes

Inject Inject slowlyslowly

CLINICAL MANIFESTATIONSCLINICAL MANIFESTATIONSofof

OVERDOSE OVERDOSE

Minimal to ModerateMinimal to Moderate

SignsSigns

Talkativeness ApprehensionTalkativeness Apprehension

Slurred speech ExcitabilitySlurred speech Excitability

Stutter EuphoriaStutter Euphoria

Dysarthria NystagmusDysarthria Nystagmus

Muscular twitching / tremors Muscular twitching / tremors

Minimal to ModerateMinimal to Moderate

Signs (cont.):Signs (cont.):

Elevated BP SweatingElevated BP Sweating

Elevated heart rate Nausea/vomitingElevated heart rate Nausea/vomiting

Elevated resp. rate DisorientationElevated resp. rate Disorientation

Failure to follow commands / reasonFailure to follow commands / reason

Lack of response to painful stimuli Lack of response to painful stimuli

Minimal to ModerateMinimal to Moderate

Symptoms:Symptoms:

Restless Visual disturbancesRestless Visual disturbances

Nervous Auditory disturbancesNervous Auditory disturbances

Numbness Metallic taste Numbness Metallic taste

Minimal to ModerateMinimal to Moderate

Symptoms (cont.):Symptoms (cont.):

Light-headed and dizzyLight-headed and dizzy

Drowsy and disorientedDrowsy and disoriented

Losing consciousnessLosing consciousness

Sensation of twitching (before actualSensation of twitching (before actual

twitching is observed)twitching is observed)

Moderate to HighModerate to High

Generalized tonic-clonic seizure activityGeneralized tonic-clonic seizure activity

followed byfollowed by

Generalized CNS depressionGeneralized CNS depression

Depressed BP, heart rateDepressed BP, heart rate

Depressed respiratory rateDepressed respiratory rate

PathophysiologyPathophysiology

Local anesthetics cross blood-brain barrier, Local anesthetics cross blood-brain barrier, producing CNS depression as level risesproducing CNS depression as level rises

eg. eg. LIDOCAINELIDOCAINE

Blood LevelBlood Level Action ProducedAction Produced

< .5 ug/ml - no adverse CNS effects< .5 ug/ml - no adverse CNS effects

0.5-4 ug/ml - anticonvulsant0.5-4 ug/ml - anticonvulsant

4.5-7.5 ug/ml - agitation, irritability4.5-7.5 ug/ml - agitation, irritability

> 7.5 ug/ml - tonic-clonic seizures> 7.5 ug/ml - tonic-clonic seizures

PathophysiologyPathophysiology

Local anesthetics exert a lesser effect on the Local anesthetics exert a lesser effect on the cardiovascular systemcardiovascular system

eg.eg. LIDOCAINE LIDOCAINE

Blood LevelBlood Level Action ProducedAction Produced

1.8-5 ug/ml - 1.8-5 ug/ml - treattreat PVCs, tachycardia PVCs, tachycardia

5-10 ug/ml - cardiac depression5-10 ug/ml - cardiac depression

>10 ug/ml - severe depression,>10 ug/ml - severe depression,

bradycardia, vasodilatation, arrestbradycardia, vasodilatation, arrest

MANAGEMENTMANAGEMENTofof

OVERDOSEOVERDOSE

Mild Reaction -slow onsetMild Reaction -slow onset

Reassure patientReassure patient

Administer O2Administer O2

Monitor vital signsMonitor vital signs

Consider IV anticonvulsantConsider IV anticonvulsant

Allow recovery or get medical help prnAllow recovery or get medical help prn

Get medical consultation, esp. if possibility of Get medical consultation, esp. if possibility of metabolic or renal dysfunctionmetabolic or renal dysfunction

Severe Reaction - rapid onsetSevere Reaction - rapid onset

Stop all treatment Stop all treatment

Place patient in supine position, feet upPlace patient in supine position, feet up

Establish airway, give O2 (BLS)Establish airway, give O2 (BLS)

If convulsions, protect patientIf convulsions, protect patient

Summon emergency medical helpSummon emergency medical help

Consider anticonvulsant drugs, vasopressorsConsider anticonvulsant drugs, vasopressors

Severe Reaction - slow onsetSevere Reaction - slow onset

Stop all treatmentStop all treatment

Establish airway, give O2 (BLS)Establish airway, give O2 (BLS)

Administer anticonvulsantAdminister anticonvulsant

Summon emergency medical helpSummon emergency medical help

Consider vasopressorsConsider vasopressors

Get medical consultation, esp. if possibility of Get medical consultation, esp. if possibility of metabolic or renal dysfunctionmetabolic or renal dysfunction

Vasoconstrictor OverdoseVasoconstrictor Overdose

Clinical manifestations:Clinical manifestations:

Fear, anxietyFear, anxiety

TensenessTenseness

RestlessnessRestlessness

TremorTremor

WeaknessWeakness

Vasoconstrictor OverdoseVasoconstrictor Overdose

Clinical manifestations (cont.):Clinical manifestations (cont.):

Throbbing headacheThrobbing headache

PerspirationPerspiration

DizzinessDizziness

PallorPallor

Respiratory difficultyRespiratory difficulty

PalpitationsPalpitations

Epinephrine OverdoseEpinephrine Overdose

Sharply elevated BP (systolic)Sharply elevated BP (systolic)

Increased heart rateIncreased heart rate

Cardiac tachyarrhythmiasCardiac tachyarrhythmias

Management - v/c overdoseManagement - v/c overdose

Stop dental treatmentStop dental treatment

Sit patient upSit patient up

Reassure patient, administer O2Reassure patient, administer O2

Monitor BP and pulse until fully recoveredMonitor BP and pulse until fully recovered

Allergic ReactionsAllergic Reactions

Type Mechanism Time Clinical Example Type Mechanism Time Clinical Example

I Antigen induc. sec/min Angioedema,I Antigen induc. sec/min Angioedema,

AnaphylaxisAnaphylaxis

IV Cell mediated 48 hrs ContactIV Cell mediated 48 hrs Contact

dermatitis dermatitis

Allergens in LocalAllergens in Local

EstersEsters - usually to the Para-amino-benzoic- - usually to the Para-amino-benzoic-acid productacid product

Na bisulfite or metabisulfite Na bisulfite or metabisulfite - found in - found in anesthetics as perservative for anesthetics as perservative for vasoconstrictorsvasoconstrictors

MethylparabenMethylparaben - no longer used as - no longer used as perservative in dental cartridgesperservative in dental cartridges

Management of Allergy Pts.Management of Allergy Pts.

If the patient gives a history of allergy to local If the patient gives a history of allergy to local anesthetics - anesthetics - Assume that an allergy existsAssume that an allergy exists

Elective proceduresElective procedures

Postpone until work-up is completedPostpone until work-up is completed

Management of Allergy Pts.Management of Allergy Pts.

Emergency treatmentEmergency treatment

Protocol #1 - no invasive treatment ( I&D, Protocol #1 - no invasive treatment ( I&D, analgesics, antibiotics)analgesics, antibiotics)

Protocol #2 - use general anesthesiaProtocol #2 - use general anesthesia

Protocol #3 - Histamine blocker (Benadryl)Protocol #3 - Histamine blocker (Benadryl)

Protocol #4 - Others: electronic dental Protocol #4 - Others: electronic dental anesthesia, hypnosis, adjunctive N2Oanesthesia, hypnosis, adjunctive N2O

Allergy - signs/symptomsAllergy - signs/symptoms

Dermatologic:Dermatologic:

Urticaria - wheals, pruritisUrticaria - wheals, pruritis

AngioedemaAngioedema

Minor rashMinor rash

Allergy - signs/symptomsAllergy - signs/symptoms

Respiratory:Respiratory:

Laryngeal edemaLaryngeal edema

BronchospasmBronchospasm

distress dyspneadistress dyspnea

anxiety cyanosis or flushinganxiety cyanosis or flushing

wheezing tachycardiawheezing tachycardia

diaphoresis use of accessorydiaphoresis use of accessory

muscles muscles

AnaphylaxisAnaphylaxis

Typical progression Typical progression **

Skin reactionsSkin reactions

Smooth muscle spasms (GI, GU, respiratory)Smooth muscle spasms (GI, GU, respiratory)

Respiratory distressRespiratory distress

Cardiovascular collapseCardiovascular collapse

*may occur rapidly, with considerable overlap*may occur rapidly, with considerable overlap

Management of ReactionsManagement of Reactions

Delayed skin reactionDelayed skin reaction

Benadryl - 50 mg stat & Q6H X 3-4 daysBenadryl - 50 mg stat & Q6H X 3-4 days

Immediate skin reactionImmediate skin reaction

Epinephrine 0.3 mg IM or SCEpinephrine 0.3 mg IM or SC

Benadryl - 50 mg IMBenadryl - 50 mg IM

Observation, medical consultationObservation, medical consultation

Benadryl - 50 mg Q6H X 3-4 daysBenadryl - 50 mg Q6H X 3-4 days

Management of ReactionsManagement of Reactions

Bronchial constrictionBronchial constriction

Semi-erect position, O2 - 6 L/minSemi-erect position, O2 - 6 L/min

Inhaler or Epinephrine 0.3 mg IM or SCInhaler or Epinephrine 0.3 mg IM or SC

Benadryl - 50 mg IMBenadryl - 50 mg IM

Observation, medical consultationObservation, medical consultation

Benadryl - 50 mg Q6H X 3-4 daysBenadryl - 50 mg Q6H X 3-4 days

Mangement of ReactionsMangement of Reactions

Laryngeal edemaLaryngeal edema

Place supine, O2 - 6 L/minPlace supine, O2 - 6 L/min

Epinephrine 0.3 mg IM or SCEpinephrine 0.3 mg IM or SC

Maintain airwayMaintain airway

Benadryl - 50 mg IV or IMBenadryl - 50 mg IV or IM

Hydrocortisone - 100 mg IV or IMHydrocortisone - 100 mg IV or IM

Perform CricothyrotomyPerform Cricothyrotomy

Management of ReactionsManagement of Reactions

AnaphylaxisAnaphylaxis

Place supine, on flat surfacePlace supine, on flat surface

ABCs of CPR, ABCs of CPR, call for medical helpcall for medical help

Epinephrine 0.3 mg IV or IM (Q 5 mins)Epinephrine 0.3 mg IV or IM (Q 5 mins)

O2 - 6 L/min, monitor vital signsO2 - 6 L/min, monitor vital signs

After clinical improvement,After clinical improvement,

Benadryl and HydrocortisoneBenadryl and Hydrocortisone

Differential DiagnosisDifferential Diagnosis

Pyschogenic reaction (Syncope)Pyschogenic reaction (Syncope)

Overdose reactionOverdose reaction

HypoglycemiaHypoglycemia

Stroke (CVA)Stroke (CVA)

Acute adrenal insufficiencyAcute adrenal insufficiency

Cardiac arrestCardiac arrest

PREVENTIONPREVENTIONofof

SYSTEMIC COMPLICATIONSSYSTEMIC COMPLICATIONS

Prior to TreatmentPrior to Treatment

Complete review of medical statusComplete review of medical status

(including vital signs)(including vital signs)

Anxiety / Fear should be assessed and Anxiety / Fear should be assessed and managed before administering anestheticmanaged before administering anesthetic

Administration of AnestheticAdministration of Anesthetic

Place pt. supine or semi-supine positionPlace pt. supine or semi-supine position

Dry site, apply topical X 1 minDry site, apply topical X 1 min

Select appropriate drug for treatment (time)Select appropriate drug for treatment (time)

Vasoconstrictor unless contraindicated Vasoconstrictor unless contraindicated

Administration (cont.)Administration (cont.)

Weakest anesthetic in the minimum volumeWeakest anesthetic in the minimum volume

(compatible with successful anesthesia)(compatible with successful anesthesia)

Inject slowly (minimum of 60 sec / 1.8 ml)Inject slowly (minimum of 60 sec / 1.8 ml)

Continually observe -Continually observe -

Never leave patient alone after injectionNever leave patient alone after injection

Administration (cont.)Administration (cont.)

Use only aspirating syringeUse only aspirating syringe

Aspirate in two planes, before injectingAspirate in two planes, before injecting

Use sharp, disposable needles of adequate Use sharp, disposable needles of adequate diameter and lengthdiameter and length