Local anesthetic complications can be classified as local or systemic. Local complications include prolonged anesthesia, needle breakage, hematoma, and soft tissue injury from needle trauma. Systemic complications include toxicity from overdose, idiosyncratic reactions that cannot be predicted, allergic reactions, and potentially life-threatening anaphylaxis. Proper technique, using the minimum effective dose, and aspirating before injection can help prevent complications. Complications are generally managed through reassurance, analgesics, antibiotics as needed, and supportive care until resolution.

2. Complications
of
local
anesthesia
Presented by:-
Dr. Salabh Singh Parihar

3. What is “local anesthesia”?
Loss of sensation in a circumscribed area of the body caused by
depression of excitation in nerve endings or inhibition of the
conduction process in peripheral nerves.

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

5. Classification
Primary or secondary
Mild or sever
Transient or permanent
Attributed to solution or needle insertion

6. TYPES OF LA
COMPLICATIONS
Local complication
Systemic complication

7. Needle breakage
Prolonged anesthesia or paresthesia
Facial nerve paralysis
Trismus
Soft tissue injury
Hematoma
Local Complications

8. Pain during injection
Infection
Edema
Sloughing of tissues
Post anesthetic intraoral lesions

9. Systemic complications
Toxicity
Idiosyncrasy
Allergy
Anaphylactic reactions

10. 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

11. TOXICITY
It refers to the symptoms manifested as a results of over dosage or
excessive administration of the solution.
Cause:
• Intravascular injection usually coupled with too rapid deposition of
solution
• Too large a volume
• Rapid absorption into bloodstream

12. 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.

13. 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

14. IDIOSYNCRASY
The term idiosyncrasy is defined as any reaction to a local anesthetic or drug
that 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.

15. 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.

16. 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 reaction
in a patient who has previously been sensitizing to a particular drug or chemical
derivative thereof.

17. ALLERGY
SYMPTOMS:
1.Rashes
2.Urticaria
3.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.

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

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

20. LOCAL REACTIONS
• Infection
• Tissue irritation

21. FAINTING OR SYNCOPE
It is due to temporary cerebral ischemia as a results of dilation of the
splanchnic B.P. & reduced cardiac output.
SIGN & SYMPTOMS
Pallor
Cold
sweating
nausea
Loss of consciousness

22. 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.

23. MUSCLE TRISMUS
Inability to open the mouth normally.
Etiology:
Injection in to muscles or ligaments
Needle borne infection
Contaminated / irritating solution
Hematoma formation in the muscle

24. MANAGEMENT
Depends 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 therapy
Warm saline rinses
Analgesics
Muscles relaxant

25. 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, TMJ
Using a non isotonic solution
Very cold solution

26. Management:
Assure the patients
Analgesics
Contaminated solution
Too rapid injection resulting in tissue distention
Numerous needle puncture

27. EDEMA
It is usually a symptom.
ETIOLOGY
• Trauma
• Allergy
• Infection
• hemorrhage

28. 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

29. 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.

30. MANAGEMENT
Antibiotics
Anti inflammatory drugs
Use disposable syringe.

31. 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

32. • 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

33. 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.

34. MANAGEMENT
• Assure the patients.
• it takes some time to disappear.

35. 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

36. MANAGEMENT
• Knowledge of normal anatomy – proper technique
• Shorter needle – PSA, minimize the number of penetration
• Discard defective needles- barbed needles
• Ice pack

37. 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

38. MANAGEMENT
• Symptomatic – pain – analgesia
• Epithelial desquamation – resolve few days
• Sterile abscess resolve  7-10 days

39. 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
• Warning sticker

40. 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

41. MANAGEMENT
• Reassure the patient
• Resolves after action of LA is over
• Eye patches to the affected – eye drops
• Contact lenses if any – removed

42. 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

43. 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.

44. References
Local Anesthesia- Stanley Malamed.
Monheim’s Local Anesthesia And Pain Control In Dental Practice.