this ppt showed in detail about complication of various nerve blocks in dental extraction LOCAL COMPLICATIONS Needle breakage Pain on injection Burning on injection Persistent anaesthesia or paresthesia Trismus Hematoma Sloughing of the tissue / soft tissue injury Facial nerve paralysis

1. SankalchandPatel University
Faculty of Dental Sciences
Narsinhbhai Patel Dental College and
Hospital
Dept. of oral and maxillofacial surgery
Complications of
LA
Dr Anil Managutti
Prof & Head
Dept of Oral and Maxillofacial
Surgery
9727756155
dranilman12@rediffmaail.com

2. Complications of Local
Anaesthesia

3. Complications
• Definition
– An anaesthetic complication may be defined as
any deviation from the normal expected pattern
during or after securing regional anaesthesia
– 2 types
• Local
• Systemic

4. • LOCAL COMPLICATIONS
1. Needle breakage
2. Pain on injection
3. Burning on injection
4. Persistent anaesthesia or paresthesia
5. Trismus
6. Hematoma
7. Sloughing of the tissue / soft tissue injury
8. Facial nerve paralysis

5. • SYSTEMIC COMPLICATIONS
– Toxicity
– Idiosyncracy
– Allergy
– Anaphylactoid reaction
– Syncope

6. • Classification
– Primary / secondary
• Primary – caused & manifested at time of anaesthesia
• Secondary – manifested later
– Mild / severe
• Mild – exhibit slight change from normal expected
pattern
- reverses itself without treatment
• Severe – manifests itself – pronounced deviation
- requires specific treatment

7. – Transient / permanent
• Transient – is one that is severe at occurrence – no
residual effects
• Permanent – residual effect; lasts for a life time even
though it is mild
Complications could be a combination of any of the above
mentioned types
Majority are either Primary Mild & Transient or Secondary
Mild & Transient

8. • Complications
– Attributed to solutions – toxicity, allergy,
idiosyncrasy, anaphylactoid reaction, local irritation
– Attributed to technique / needle – syncope,
muscle trismus, pain, edema, hematoma

9. Needle breakage
• Cause –
– Unexpected movement – patient (if patient
movement is opposite to path of needle insertion)
– Multiple used needle
– Defective manufacture of needles/barbed needles
– smaller gauge – more likely to break

10. • Prevention
– Correct gauge – 25 gauge
– Long needles – prevent penetration till hub
– Not to redirect when in tissue
• 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

11. • Precautions
– Avoid bony contact
– Avoid heavy pressure
– Avoid movement of needle and patient

12. Pain on injection
• Causes –
• Careless injection technique
• Multiple used needle
• Rapid deposition
• Problems –
– Pain – patient anxiety – unexpected movements
• Prevention –
– Proper technique – sharp needles
– Enter topical anaesthetics
– Inject slowly – solution sterilized
– Check temperature of solution

13. Burning on injection
• Causes
– Due to pH of solution  5 (LA) – 3 (LA+VC)
– Rapid injection
– Contamination
– Warm solution
• Problems
– pH  disappears upon LA action – no residual
effect
– Contaminated solution  other complications –
trismus, edema, paraesthesia

14. • Prevention
– Slow injection – 1ml / minute
– Cartridge stored at room temperature – away from
containers with alcohol / other agents

15. Persistent anaesthesia / paresthesia
• Causes
– Direct trauma to nerve – bevel of needle
– LA solution containing neurotoxic substance –
alcohol
– Injection of wrong solution
– Hemorrhage / infection – near to nerve
• Problem
– Persistent anaesthesia – usually rare
– Biting / thermal / chemical insult – without patient
awareness
– When lingual nerve is involved – taste impaired

16. • Prevention
– Proper care & handling of dental cartridge
– Adherence to injection protocol
• Management
– Usually resolve in 8 weeks
– Periodic recall & check up of patients
– Persistence – consult neurosurgeon
– TENS
– Recall patient every 2 months for check up

17. Trismus
• Definition
– “difficulty in opening the jaws due to muscle spasm”
• Causes
– Trauma – muscle / blood vessel
– Irritating solution
– hemorrhage
– Infection
– Multiple needle punctures
– LA have been known to have slight myotoxicity
– Excessive volume – distension of tissues
• Problems
– Pain / hypomobility

18. • Prevention
– Use of sharp, sterile, disposable needle
– Aseptic technique
– Practice atraumatic methods
– Avoid repeated injections
– Use minimum volume
– Control infection

19. • Management
– Heat therapy
• Warm saline rinses, moist hot packs
– Analgesics
• Aspirin, Codeine (30-60mg), muscle relaxants
– Initial physiotherapy
• Thrice a day
– Antibiotic regime
• Possibility of infection

21. Hematoma
• “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
• Prevention
– Knowledge of normal anatomy – proper technique
– Shorter needle – PSA, minimize the number of penetration
– Discard defective needles- barbed needles

22. • Management
– Immediate – apply firm pressure  5-10minutes
• Inf. Alv. Nr. Block – medial aspect of ramus
• Infra orbital, Mental, Incisive block – directly over
foramen
• PSA – pressure on soft tissue with finger as
posteriorly as tolerated by patient – medial superior
direction
• Patient to be reviewed after 24 hours, advice
analgesics, cold application upto 4-6 hours, warm-
pack application next day

23. Infection
• Comparitively rare complication
• Instrument needle ,solution to be as aseptic as
possible
• Area & operative hands – cleaned
• Avoid passing needle through infected area
• Use disposable syringes

24. Edema
• Causes
– Trauma during injection
– Infection, hemorrhage
– Allergy (Angioedema)
– Injection of irritating solution
• Problems
– Pain & dysfunction
– Airway obstruction

25. • Prevention
– Proper care & handling of armamentarium
– Atraumatic injection technique
– Complete medical evaluation prior to injection
• 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 /
Cricothyroidectomy

26. Sloughing of tissue
• 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
• Prevention
– Topical – for not more than 1-2 minutes
– VC – minimal concentration in solution

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

28. 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

29. Facial nerve paralysis
• Cause
– LA solution into parotid gland – usually while
giving Inf Alv Nr. Block, Akinosis technique
• 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

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

32. Systemic complications
• Toxicity / toxic overdose
– “Signs and symptoms that result from an overly high blood
level of a drug in various target organs and tissues”
– Predisposing factors
• Age – any age
• Weight – greater the body weight greater is the amount of dose
tolerated before overdose reaction
• Sex – during pregnancy – renal function disturbed – females more
affected at this time
• Diseases – hepatic & renal dysfunction reduced breakdown
• Congestive heart failure – less liver perfusion
• Genetics – pseudocholinesterase deficient – toxicity - Ester LA

33. • Drug factors – Vasoactivity – vasodilation – increase in
blood concentration
• More concentration – greater risk
• Dose- smaller dose should always be preferred
• Route of Administration – Intravascular – increased
toxicity
• Rate of injection – slower rate preferred
• Vascularity of injection site – more vascular – greater
absorption
• Presence of Vasoconstrictor – with VC less absorption

34. – Causes of toxicity –
• Biotransformation usually slow
• Drug – slowly eliminated by kidney
• Too large a total dose
• Absorption from injection site - rapid
• Accidental intra-vascular injection
– Symptoms –
• CNS – cerebral cortical stimulation – talkative, restless,
apprehensiveness, convulsions
• Cerebral cortical depression – lethargy, sleepiness,
unconsciousness
• Medullary stimulation – increased B.P, Pulse rate,
Respiration

35. – Medullary depression – mild fall in B.P– severe cases drops to
0 , Pulse , Respiration – similar effect
• Treatment
– Mild overdose reaction – slow onset reaction – > 5 mins
administer Oxygen (prevent acidosis), monitor vital signs, in
case of convulsions – anti-convulsants (diazepam/midazolam
infusion)
– Slower onset - >15 mins – same procedure
– Severe overdose reaction – rapid onset – 1 minute –
unconsciousness with or without convulsion, patient in supine
position, convulsions – protect hand, leg, tongue, BLS,
administer anti-convulsant,use of vasopressor(phenyl ephrine)
i.m if hypotensiom presists.
– post seizure – CNS depression usually present

36. Idiosyncrasy
• “It is an adverse response that is neither an
overdose nor an allergic reaction”
• Common cause – some underlying
pathology/psychological /genetic mechanism
• Psychotherapy may be helpful
• Treatment – symptomatic ..remember ABC’s!

37. Syncope
• “transient loss of consciousness that is caused due to cerebral
ischemia (neurogenic shock)”
• Anxiety – increased blood supply to muscles, sitting position
2mm Hg, less pressure – cerebral arteries
• Clinically pallor, light headedness, dizziness, tachycardia &
palpitation – may further lead to Unconsciousness
• Treatment – discontinue procedure, supine position-
(trendelenburg position), deep breathing, O2 administration if
required, BLS

38. Allergy
• “hypersensitive state acquired through exposure to a particular
allergen reexposure to which produces a heightened capacity to
react”
• 1 % of all reaction in LA is allergy
• Predisposing factors
– Hyper sensitivity to ester more common-procaine
– Most of patients allergic to methyl paraben
– Recently allergy to sodium meta bi sulfide is also increasing
Precautions---
Ho of allergy to be recorded
Ho any asthmatic attack to be noted.
Always better to test the patient for allergy before treatment.

39. – Consultation and allergy testing
• Refer doubtful cases for allergic skin test – sub cutaneous
test most sensitive.
• Informed consent that includes cardiac arest end death to
be included.
– Signs and symptoms of allergy.
• Dermatological------ urticaria –wheal and smooth elevated
patch seen, ------angio oedema—localised swelling – face
hands, common
• Respiratory– broncho spasm, respiratory distress,
– dysnea, wheezing, flushing, tachycardia etc.

40. –Laryngeal edema – type of angio
neurotic oedema- life threating.
•Edema upper air way – laryngeal edema
• Lower air way affect bronchioles- small.

41. –Management
•skin reactions-
–Delayed – non life threatening - oral
histamine blockers- 50 mg diphenhidramine,10
mg chlorpheniramine 3-4 days.
–Immediate reaction—with conjunctivitis
rhinitis- vigorous management.
– 0.3 mg epinephrine. IM
– 50 mg diphenhydramine Im
– medical help summoned.

42. – Observe patient for minimum of 60 min
– Oral histamine blockers for 5 days.
– Respiratory reaction –
• patient in comfortable position.
• administer - oxygen
• Admn epinephrine- bronchodilator
• Observe for 60 min , advise anti histamines to prevent relapse.
• Histamine blockers Im
– Laryngeal edema-
• Patient position ,oxygen, broncho-dilator, iv anti histamines.
• If condition not improving cricothyrotomy - achieve patent air
way if necessary give artificial ventilation.

43. • Patient with confirmed allergy status-
– if patient allergic to any one type of anesthetic
ester / amide use the other.
– Use histamine blocker like diphenhydramine as
anesthetic.
– General anesthesia
– alternative method of pain control –
• electric anesthesia / hypnosis.