1. LOCAL ANAESTHESIA
Local and Systemic
Complications of LA
Dr. Adel I. Abdelhady
BDS, MSC, (EG) PhD (EG,USA)
Oral and Maxillofacial Surgery Dept.
College of Dentistry, Dammam University, KSA. .
2. Unannounced Quiz
What is the LA?
The lipid solubility determine the……….
The degree of protein binding of a local
anesthetic agent determines the…………
The pKa of LA determines
its……………
3. OBJECTIVS
The student shall be able to explain the signs
and symptoms of side effects, and Localized and
systemic complications , how to diagnose and the rational
of their treatment.
Systemic complications, how to diagnose and manage
Doctor factor (wrong technique) and how to avoid
Vasoconstrictor
LA
Needle
Patient factor
4. Factors influencing injection
discomfort?
The needle:
Sharp & small gauge
The syringe:
Aspirating to avoid local and systemic effects
The cartridge:
Smooth bung to avoid judder and allow steady injection
The solution:
Temperature: >15 – 37< is not detected by the patient.
pH: (LA with VC is acidic (3.2)…..Painful, LA without VC is
less acidic (6.8)……….Painless
Rate of injection: faster injection is painful.
8. Needle Breakage
Prevention
Use large needles
Use long needles for deep injection,>18mm
Never insert to hub
Redirect only when adequately withdrawn
14. Management of failed local
anaesthesia
•
•
•
•
•
Check anatomical landmarks
Repeat injection
Consider alternate or additional technique
Consider whether anxiety may be contributory
Settle pain and inflammation and try again about
a week later
16. Pain during injection
Pain during injection:
Intraepithelial injection leading to ballooning
Subperiosteal injection cause discomfort due to
injection into noncompliant tissues
Too rapid injection a rate of 30 sec. per cartridge
is ideal
25. Hematoma
Due to needle accidentally penetrate a b.v. leading to effusion of
blood into extravascular spaces
Prevention
Care with needle placement
Minimize number of injections
Don't probe with needle
Modify technique
o
short needles
o
penetration depth
o
When hematoma is large prescribe antibiotics to prevent
infection
30. Cartridge failure
L A cartridge may fail when subjected to high
pressure during intraligamentary or palatal
injection
To prevent this rate of injection should be slow
37. Complications of LA
Systemic adverse effects complications:
Toxicity (due to LA & VC)
Methaemoglobinaemia:
General NS toxicity
Cardiovascular Toxicity (Haemoglobin contains iron in
Ferric not Ferrous state leading
Drug interactions
to poor oxygenation and
Allergic effects
cyanosis (Treated by IV 1%
Fainting/syncope
methylene blue 1.5 mg/kg. oIdiosyncrasy
toluidine (oxidise Iron) is a
metabolic product of Prilocaine.
Articaine, Benzocaine?
38. SYSTEMIC COMPLICATION
Fainting
or syncope
Fainting or syncope frequently occurs because of
patient frightened at the thought of receiving an
injection
Predisposing factors:
1-Psychogenic factors: fear , anxiety and sight
of unpleasant object as blood or surgical instrument
2-Non-psychogenic: factors as pain especially sudden
unexpected, sitting in waiting area for a long period,
hunger causing low glucose supply or exhaustion
,poor physical condition
39. Fainting
Clinical features
1-Pre-syncope period :
The patient feels faint and may feel nauseating.
Paleness and coldness of hand, cold sweating
over the forehead and hands, hypotension ,
tachycardia and deep irregular respiration
40. Syncope
Loss of consciousness:
Hypotension , bradycardia and shallow irregular
respiration. Possible muscular twitches (tremors) or
convulsive movements of the extermities.
Progression may occur into muscular relaxation and
apnoea
2-Post-syncope period
After regaining consciousness the patient feels weak,
nauseating and mentally confused for few minutes.
41. Patho-physiology
Stress causes
Management
secretion of adrenalin into the circulation this
cause peripheral vascular resistance and blood flow to the
muscle to prepare body to response to this stressful condition
1-Stop any dental procedure
2-Place patient in supine or trendelenberg position to facilitate
venous return to the heart
3-Maintain patient airway , respiratory stimulants by aromatic spirit
of ammonia
4-Oxygen administration might be needed
5-Keep the patient in this position under observation
6-For persistent bradycardia give atropine 0.4 mg i.v
43. Cause of Overdose Levels
Total dose is too large
Absorption is too rapid
Intravascular injection
Biotransformed too slowly
Eliminated too slowly
44. Manifestations and management of LA
toxicity a
Manifestations
•Mild toxicity:
Talkativeness, anxiety,
slurred speech, confusion
Moderate toxicity:
Stuttering speech,
nystagmus, tremors,
headache, dizziness, blurred
vision, drowsiness
Management
• Stop administration of all local
anaesthetics
• Monitor vital signs
• Observe in office for 1 hr
• Stop administration of all local
anaesthetics
• Place in supine position
• Monitor vital signs
• Observe in office for 1 hr.
45. Manifestations and management of LA toxicity b
Manifestations Management
Sever toxicity:
seizure, cardiac
dysrhythmia or
arrest.
• Place in supine position
• If seizure, protect from nearby objects and
suction oral cavity if vomiting occurs
• Have someone summon medical assistance
• Monitor vital signs
• Administer oxygen
• Start IV
• Administer diazepam 5-10 mg slowly or
midazolam 2-5 mg slowly
• Institute BLS if necessary
• Transport to emergency care facility
46. General Principles
No drug exerts a single action
No drug is non-toxic
Potential toxicity is user dependent
Adverse Drug Reactions
Side effects
Overdose
47. Adverse Drug Reactions
Altered recipient
Disease process
Emotional disturbances
Genetic aberrations
Idiosyncrasy
51. Adverse Drug Reactions
Allergic reaction
Immediate - anaphylaxis
Delayed - contact dermatitis
Not dose related
May be systemic or localized
Unrelated to pharmacological effects
Exaggerated immune system response
52. Intravascular Injection
Occurrence varies with type of injection:
Nerve Block
% positive aspirate
Inf. alveolar
11.7
Mental/Incisive
5.7
Post. sup. alv.
3.1
Ant. sup. alv./ Buccal
<1
55. Management - v/c overdose
Stop dental treatment
Sit patient up
Reassure patient, administer O2
Monitor BP and pulse until fully recovered
56. Allergic Reactions
Type Mechanism Time Clinical Example
I Antigen induc. sec/min Angioedema,
Anaphylaxis
IV Cell mediated 48 hrs
Contact dermatitis
57. Allergens in Local
Esters - usually to the Para-amino-benzoic-acid
product
Na bisulfite or metabisulfite - found in
anesthetics as perservative for vasoconstrictors
Methylparaben - no longer used as perservative
in dental cartridges
58. Management of Allergy Pts.
If the patient gives a history of allergy to local
anesthetics - Assume that an allergy exists
Elective procedures
Postpone until work-up is completed
61. Anaphylactic shock
Anaphylactic shock is anaphylaxis associated with
systemic vasodilation which results in
low blood pressure. It is also associated with severe
vasoconstriction of the bronchioles to the point where
the individual is unable to breathe
Smooth muscle spasms (GI crampy abdominal pain,
diarrhea, and vomiting )
Respiratory distress shortness of breath, wheezes or
stridor
Cardiovascular collapse
62. Management of Reactions
Delayed skin reaction
Benadryl - 50 mg stat & Q6H X 3-4 days
Immediate skin reaction
Epinephrine 0.3 mg IM or SC
Benadryl - 50 mg IM
Observation, medical consultation
Benadryl - 50 mg Q6H X 3-4 days
63. Management of Reactions
Bronchial constriction
Semi-erect position, O2 - 6 L/min
Inhaler or Epinephrine 0.3 mg IM or SC
Benadryl - 50 mg IM
Observation, medical consultation
Benadryl - 50 mg Q6H X 3-4 days
64. Mangement of Reactions
Laryngeal edema
Place supine, O2 - 6 L/min
Epinephrine 0.3 mg IM or SC
Maintain airway
Benadryl - 50 mg IV or IM
Hydrocortisone - 100 mg IV or IM
Perform Cricothyrotomy
65. Management of Reactions
Anaphylaxis
Place supine, on flat surface
ABCs of CPR, call for medical help
Epinephrine 0.3 mg IV or IM (Q 5 mins)
O2 - 6 L/min, monitor vital signs
Benadryl and Hydrocortisone
67. References
1.
2.
SF Malamed: Pain and anxiety control for
the conscious dental patient, 1997.
Meechan, et al., Hand book of local
anaesthesia, 1998.
68.
69. Suggested maximum dosage of local
anaesthetics
Drug
Common
brand
Concentration
Percentage
Maximum
number
of 1.8 ml
cartridges
Lidocaine
Xylocaine
2%
10
Lidocaine +
Epin.
Xylocaine with
epinephrine
2% lidocaine
1:100000 epinephrine
10
Mepivacaine
Carbocaine
3%
6
Mepivacaine +
norad.
Carbocaine with
neo-cobfrin
2% mepivacaine
1:20000 levonordefrin
8
Prilocaine
Citanest
4%
6
Bupivacain +
Adren.
Marcaine with
epinephrine
0.5% bupivacaine
1: 200 000
10
Etidocaine
Duranest with
1.5% etidocaine
15