Complications of

local anesthesia

Presented by:-Dr. Salabh Singh Parihar

What is “local anesthesia”?

Loss of sensation in a circumscribed area of the body caused bydepression of excitation in nerve endings or inhibition of theconduction process in peripheral nerves.

Complication

“Any deviation from the normally expected pattern during or after the securing regional analgesia.”

Classification

Primary or secondary

Mild or sever

Transient or permanent

Attributed to solution or needle insertion

TYPES OF LA COMPLICATIONS

Local complication

Systemic complication

Needle breakage

Prolonged anesthesia or paresthesia

Facial nerve paralysis

Trismus

Soft tissue injury

Hematoma

Local Complications

Pain during injection

Infection

Edema

Sloughing of tissues

Post anesthetic intraoral lesions

Systemic complications

Toxicity

Idiosyncrasy

Allergy

Anaphylactic reactions

KEEP IN MIND

A - Airway - clear adequate respiration

B - Bleeding - stopped achieve inlet to vessels

C - Circulation - fluid if needed

D - Drugs to treat the present condition

TOXICITYIt refers to the symptoms manifested as a results of over dosage orexcessive administration of the solution.

Cause: • Intravascular injection usually coupled with too rapid deposition of

solution

• Too large a volume

• Rapid absorption into bloodstream

Symptoms:(clinically)Talkativeness, restlessness, apprehension, excitement, convulsions,

lethargy, sleepiness, unconsciousness

Increase or decrease in BP, pulse rate and respiration, nausea and vomiting is also seen.

Prevention:• Aspiration must be performed before injecting.

• Smallest possible volume of drugs should be used.

• A vasoconstrictor should be employed with the local anesthetic.

Treatment:-

Mild stimulation - no t/m stop further injection

Moderate stimulation - I.V. inj. Of Barbiturates 0.2% solution of sodium thiopental oxygen inhalation

Convulsions phase - anticonvulsant I.V./I.M. coramine (150-450 mg I.V.), metrazol (100mg I.V.) oxygen inhalation

Depression phase - artificial respiration I.V. fluid

IDIOSYNCRASY

The term idiosyncrasy is defined as any reaction to a local anesthetic or drugthat cannot be classified as toxic or allergic.

Idiosyncrasy have no relation to the pharmacology of the drug and may vary in degree from day, to day even in the same patient.

THE TREATMENT FOR IDIOSYNCRASY TYPE OF EMERGENCY:

The patients airway must be maintained and adequate oxygenation assured.

• Steps should be taken to evaluate the circulation and support it by positional changes, drugs, or parenteral fluids.

• Precautions may also be exercised to protect the patient from injury to himself as a result of convulsive seizures, loss of consciousness or similar reactions.

ALLERGY• Allergy is a hypersensitive reaction that occurs through exposure to an antigen.

CAUSE:The primary cause of allergic reactions is a specific antigen-antibody reactionin a patient who has previously been sensitizing to a particular drug or chemical derivative thereof.

ALLERGYSYMPTOMS:1.Rashes2.Urticaria3.Mucous membrane congestion a. Rhinitis b. Asthmatic symptoms

PREVENTION:1. Adequate preanesthetic evaluation must be done.2. No drug or drugs should be used if the patient gives a history of previous allergic

reactions to them.

ANAPHYLACTIC REACTIONS

Anaphylaxis is a severe form of allergic reactions occurs suddenly &end fatally in which sudden violent loss of vasomotor tonus.

CLINICALLY

• Drop in B.P.• Weak rapid pulse• Death MANAGEMENT Benadryl 20 – 40 mg I.V. or I.M. Epinephrine 1:1000 concentration

LOCAL REACTIONS

• Infection

• Tissue irritation

FAINTING OR SYNCOPE

It is due to temporary cerebral ischemia as a results of dilation of the splanchnic B.P. & reduced cardiac output.

SIGN & SYMPTOMSPallorColdsweating nauseaLoss of consciousness

MANAGEMENT• Stop dental procedure

• Place patients in supine position with slight head down or elevate the legs to increase cerebral circulation.

or • Place the hands of the patient behind his head and bend him forward

until his head is in b/w the knee to (produce pressure on the splanchnic B.P. to replace the blood that drained from the head).

• Aromatic spirit (ammonia) held under the nose of the pt. for several breath.

MUSCLE TRISMUS

Inability to open the mouth normally.

Etiology: Injection in to muscles or ligaments Needle borne infectionContaminated / irritating solutionHematoma formation in the muscle

MANAGEMENTDepends upon the cause.

• It is due to trauma it slight muscle exercise & during therapy to relieve pain if present.

• If due to infection this needs antibiotics. Heat therapyWarm saline rinsesAnalgesicsMuscles relaxant

PAIN DURING INJECTION

Pain during or after the administration of a regional anesthetic is very common.

ETIOLOGY: Injection in to a muscle or ligament, parotid gland, TMJUsing a non isotonic solutionVery cold solution

Management:

Assure the patients

Analgesics

Contaminated solution

Too rapid injection resulting in tissue distention

Numerous needle puncture

EDEMA

It is usually a symptom.

ETIOLOGY

• Trauma• Allergy• Infection • hemorrhage

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

INFECTION

Contaminated non sterile needle or solution.

Carrying surface bacteria from non sterile mucous membrane in to the deeper structures with the tip of the needle are the causative factors.

Injection in to infected area.

MANAGEMENTAntibiotics

Anti inflammatory drugs

Use disposable syringe.

NEEDLE BROKEN

CAUSE:

• Unexpected movement – patient (if patient movement is opposite

to path of needle insertion)

• Multiple used needle

• Defective manufacture of needles

• smaller gauge – more likely to break

• On most occasious accidental breakage takes place at the hub.

• This enables the operator to remove the broken needle by grasping the portion remaining in view.

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

PROLONGED ANESTHESIA

ETIOLOGY: contamination of the anesthetic solution with alcohol or some other germicidal solution.

Needle trauma to nerve tissue.

Trauma & swelling of the soft tissue in proximity to the nerve.

MANAGEMENT

• Assure the patients.

• it takes some time to disappear.

HAEMATOMA & ECCHYMOSIS “effusion of blood into extra-vascular spaces”

Causes• Arterial & venous puncture – common in PSA & Inf. Alv. nerve blocks• Patients with bleeding disorders

Problem• Bruise – may / may not be visible extra-orally• Complications – pain & trismus • Swelling & discoloration

MANAGEMENT

• Knowledge of normal anatomy – proper technique

• Shorter needle – PSA, minimize the number of penetration

• Discard defective needles- barbed needles

• Ice pack

SLOUGHING & ULCERATION

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

MANAGEMENT

• Symptomatic – pain – analgesia

• Epithelial desquamation – resolve few days

• Sterile abscess resolve 7-10 days

SOFT TISSUE INJURYCauses:• 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 • Warning sticker

FACIAL NERVE PARALYSIS

Cause• LA solution into parotid gland – usually while giving Inferior Alveoler Nr. Block,

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

withdrawal

MANAGEMENT

• Reassure the patient

• Resolves after action of LA is over

• Eye patches to the affected – eye drops

• Contact lenses if any – removed

POST ANESTHETIC INTRAORAL LESION

Ulcers are developed in the mouth after 2 days of intraoral LA

Cause Trauma to the tissue by the needle, local aesthetic solutions cotton swab or ay other instruments may activate the latent form of the disease like herpes simplex, recurrent apthous stomatitis that was present in the tissues before injection

Problems Acute sensitivity in the ulcerated area

conclusion

The best way to avoid nearly all complications relating to administration of local anesthetics is to use the right technique and to have a good knowledge of the anatomy of the trigeminal nerve and the adjacent anatomical structures.

However, if complications occur, the dentist should know how best to manage them.

References Local Anesthesia- Stanley Malamed.

Monheim’s Local Anesthesia And Pain Control In Dental Practice.