Complications Of Local Anesthesia

• DrdDr. Abhishek ShahPart - I (PG)

COMPLICATIONS ASSOCIATED WITH LA

Are of two types

• LOCAL COMPLICATIONS

• SYSTEMIC COMPLICATIONS

LOCAL COMPLICATIONS

• Needle breakage• Persistent anesthesia and paresthesia• Facial nerve paralysis• Trismus• Soft tissue injury• Hematoma • Pain on injection• Burning on injection• Infection • Edema• Sloughing of tissue• Post anesthetic intraoral lesions

NEEDLE BREAKAGE

CAUSES:• Sudden unexpected movement by patient• Needle of smaller gauge• Previously bend needle

PREVENTION:o Use larger gauge needle

o Use long needles

o Don’t insert the needle into tissues to the hub unless it is absolutely essential for the success of technique

o Don’t redirect the needle once it is inserted into tissues

MANAGEMENT:

WHEN THE NEEDLE BREAKS 1.Remain calm and don’t panic2.Instruct the patient not to move3.If the fragment is visible try to remove it with

cotton pliers or with small hemostat.

• Shira RB , Emergencies in Dental Practice, ed 3, Philadelphia, 1979

• IF THE NEEDLE IS LOST AND CANNOT BE READILY RETRIEVED

1. Do not proceed with incision2. Calmly inform the patient and attempt to allay fear.3. Note the incident in patients record4. If the needle is superficial and is easily located through

radiological and clinical examination then removal with competent oral surgeon is possible

5. If the needle is located in the deeper tissue or is hard to locate permit it to remain with out an attempt at removal.

• PERSISTANT ANESTHESIA- PARATHESIA CAUSES• Trauma to any nerve• Injection of contaminated LA• Trauma to nerve sheath

• MANAGEMENT• It generally resolves within 8 weeks without

treatment only if damage to nerve is severe then the paresthesia will be permanent

• Nickel AA, Anesth Prog 37, 42-45,1990

FACIAL NERVE PARALYSIS CAUSES• Introduction of LA solution into the deep lobe of parotid gland EFFECTS• Loss of Motor Function to the Muscles of Facial Expressions.• Minimal or No Sensory Loss.• Unilateral Paralysis• Patient is unable to Voluntarily Close one eye.

MANAGEMENT• Reassure the patient • Advice the patient for periodically close the

eyelid• Contact lens should be removed• Record the incident on patients chart

TRISMUS Defined as Prolonged muscle spasm of the jaw muscles by

which the normal opening of mouth is restricted.

CAUSES• Trauma to muscles or blood vesicles in the infra temporal

space• Irritation of the tissues• Hemorrhage • Low grade infection• Excessive volume of local anesthetic solution

PREVENTION• Use sharp and sterile disposable needles• Clean the site of injection with an antiseptic solution• Practice atraumatic insertion• Avoid repeat injections• Use minimal effective volume• Hinton and associates reported onset of trismus 1-6 days post

treatment

MANAGEMENT • Heat therapy• Warm saline rinse• Analgesic ( Aspirin 325 mg)• Muscle relaxants ( Diazepam 10 mg Bid) • Physiotherapy • Chewing gums

HEMATOMA Effusion Of Blood Into Extravascular Spaces

CAUSES• Inadvertent nicking of blood vesicles

PREVENTION• Know the normal anatomy• Modify the injection technique• Use a short needle for PSA nerve block• Minimize the number of needle penetration• Never use a needle as probe in tissue

MANAGEMENT

IMMEDIATE: when swelling becomes evident direct pressure should be applied to the site of bleeding

INFERIOR ALVIOLAR NERVE BLOCK: pressure is applied to the medial aspect of ramus

INFRA ORBITAL NERVE BLOCK : pressure applied to the skin directly over the infra orbital foramen

MENTAL OR INCISIVE : pressure over mental foramen

BUCCAL NERVE BLOCK: pressure at the site of bleeding

PSA NERVE BLOCK: infra temporal space can accommodate a large volume of blood digital pressure can be applied to the soft tissue in the mucobuccal fold as far as distally as can be tolerated.

Subsequent :• Do not Apply Heat for at least 4 to 6 hours after incident • If soreness develops , advice analgesics • Discoloration usually resolves in 7 to 14 days• If limitation of movement of jaws develops , begin

treatment as described for trismus • Warm moist cloth 20 minutes hourly• Apply Ice to the region immediately on recognition of

hematoma• Time

PAIN ON INJECTION CAUSES• Careless injection technique• Dull needle• Rapid deposition of solution• Needle with barbs• Stacy GC et al, oral surg oral med 77, 585-588,1994

PREVENTION• Proper technique of injection• Use sharp needle• Use topical anesthetic prior to injection• Use sterile local anesthetic solution• Slow injection technique

BURNING ON INJECTION CAUSES• pH of the solution• Wahl and associates compared the pain on injection of

prilocaine plain to lidocaine with epinephrine (1:100,000) and found no difference.

• When bupivacaine with epinephrine (1:200,000) compared with prilocaine plain more pain was reported

Rapid injection of LA • Contamination of LA cartridges

• PREVENTION • Slow injection• LA should be at room temperature

INFECTION CAUSES• Contamination of needle prior to injection• Improper technique in handling the LA equipment

PREVENTION• Use disposable needles• Properly care for and handle needles• Properly care for and handle cartridges • Properly prepare the tissue

MANAGEMENT

• Antibiotics • Analgesics• Muscle relaxants• physiotherapy

EDEMA CAUSES• Trauma during injection• Infection• Allergy• Hemorrhage• Injection of irritating solution PREVENTION• Properly care for and handle LA solution• Use atromatic injection technique• Complete and adequate medical evaluation

MANAGEMENT

• Resolve in 1 to 3 days

• Following haemorrhage it will resolve over 7 to 14 days

• Edema produced by allergy is more life threatening type

If edema occurs in any area where it comprises breathing treatment consists of administration of epinephrine and corticosteroids.

SLOUGHING OF TISSUE Causes• Epithelial desquation1. Application of topical anesthetic for prolong period2. Heightened sensitivity of tissues to chemical agents3. Reaction in an area where topical anesthetic is applied

• Sterile abscess1. Secondary to prolong ischemia2. Always occur in the tissue of hard palate

PREVENTION• Use topical anesthetic as recommended• Allow the solution to contact the mucous

membrane for 1 to 2 min• When using vasoconstrictor for homeostasis

don’t employ overly concentrated solutions

MANAGEMENT• Management may be symptomatic• Topically applied ointment such as orabase to

minimize irritation

POST ANESTHETIC INTRAORAL LESSIONS

CAUSES• Recurrent aphthous stomatitis• Herpes simplex• Trauma to the tissue by needle and LA solution

MANAGEMENT• Primary management is symptomatic • Viscous lidocaine can be applied• A mixture of equal amount of diphenhydramine and milk of

magnesia rinse in the mouth effectively coats the ulceration• Orabase a protective paste provides a degree of pain relief.

SYSTEMIC COMPLICATIONS CLASSIFICATION OF ADVERSE DRUG

REACTIONS- TOXICITY1. Toxicity caused by direct extension of

pharmacological effects• Side effects• Over dose• Local toxic effects2. Toxicity caused by alteration in the recipient• Presence of disease• Emotional disturbances• Genetic aberrations • Idiosyncrasy 3. Toxicity caused by allergy to the drug

Toxicity of Local anesthetics

• Toxins are poison.• All drugs are poison when administered too

much• Methylparaban has been excluded from all L.A

Cartridges manufactured in USA from 1984.• Overdose is also a Synonym for toxic reaction

Because 99% of total toxicity is due to overdose.

LOCAL ANESTHETIC OVERDOSE

PRE DISPOSING FACTORS:

1. PATIENT FACTORS• Age• Weight• Sex• Presence of disease• Genetics• Mental attitude and environment

2. DRUG FACTORS

• Vasoactivity• Concentration• Dose• Route of administration• Rate of injection• Vascularity of injection site• Presence of vasoconstrictor

CLINICAL MANIFESTATION OF LOCAL ANESTHETIC OVERDOSE

SIGNS:MINIMAL TO MODERATE OVERDOSE LEVELS:o Apprehensiono Talkativenesso Excitabilityo Slurred speecho Generalized stuttero Muscular twitchingo Nystagmus, dysarthriao Sweating , vomitingo Elevated BP, heart rate and respiratory rate

MODERATE TO HIGH BLOOD LEVELS:o Generalized tonic clonic seizure, followed byo Generalized CNS depressiono Depressed BP, heart rate and respiratory rate

SYMPTOMS:o Light headednesso Restlessnesso Nervousnesso Numbnesso Metallic tasteo Visual disturbanceso Auditory disturbances (tinnitus) o Drowsinesso Loss of consciousness

ALLERGIC REACTIONS• 1% of all reactions occuring during administration of LA

are allergic in nature.• Caused by antigen – antibody reaction leading to

release of histamine or histamine like substances.• Most commonly methylparaben has been implicated in

production of allergic reactions.

• Signs and Symptoms:• Fever• Edema• Urticaria• Dermatitis• Bronchospasm• Systemic Anaphylaxis

Prevention:• Medical History Questionnaire – -Describe your Reaction -How was your reaction treated -What position were you in at the time of the reaction -What is the name, address, and telephone number of a Doctor in whose office this reaction occurred• Consultation • Allergy Testing – though no form of allergy testing is 100% reliable• Alternative L.A. solution• Alternative Techniques of Pain Control

Treatment:• Bronchospasm- 1. P-A-B-C-D 2. Administer Oxygen3. Administer Epinephrine or Other Bronchodilator such as

Albuterol via inhalation4. Adm AntiHistamines (50 mg Diphenhydramine)5. Medical Consultation

• Skin Reaction- 1. Oral Histamine Blockers2. Observation3. Medical Consultation4. If skin reaction is Immediate , administer epinephrine.

IDIOSYNCRASY

• Any reaction to LA that cannot be classified as toxic or allergic is often called idiosyncrasy.

• TREATMENT – • Purely symptomatic.• Aimed at maintenance of patent airway and

cardiovascular support.

CONCLUSION

• Local anesthesia is required for almost all the procedures performed in present day dentistry. Hence we as the dentists should be aware of various techniques, adverse effects, actions and indications along with the pharmacological aspects so that we can use it judiciously according the patients condition.