Local complication of local anaesthesia

..

1. Local Complications of Local
Anesthesia
Dr. Sairankhurshed
B.D.S., M.Sc. Oral Surgery

2. Local complications of local anesthesia
1.Needle breakage
2.Prolonged anesthesia or
paresthesia
3.Facial nerve paralysis
4.Trismus
5.Soft tissue injury
6.Hematoma
7. Pain on injection
8. Burning on injection
9. Infection
10. Edema
11. Sloughing of tissues
12. Post-anesthetic intraoral
lesions

3. 1. Needle breakage
Needlebreakageintheoralcavityafterlocal
anesthesiaisararecomplication.

5. Why an anesthetic needle may be broken during
an injection?
1)Defects of the injection needle itself
2)Its reuse after bending the tip of the needle.
3)Short needles are used
4)Narrower needles (30 gauge instead of 27 or 25)
5)Changing direction of the needle when inserted into the tissues
6)sudden unexpected movement by the patient while the needle is
still embedded in tissue
7)forceful contact with bone

6. TABLE 17-1 Summary of Reports of Broken Dental
Needles
Inferior alveolar
nerve block
Posterior superior
alveolar nerve
block

7. 1.Donotuseshortneedlesforinferioralveolarnerveblock
2.Donotuse30gaugeneedlesforIANB.
3.Donotbendneedleswheninsertingthemintosofttissues.
4.Donotinsertaneedleintosofttissuetoitshubunlessitis
absolutelyessentialforthesuccessoftheinjection.
4.Observeextracautionwheninsertingneedlesinyoungerchildrenor
extremelyphobic.
Prevention

8. Management
Immediate
referral of the
patient to an
appropriate
specialist ( oral
and
maxillofacial
surgeon) for
evaluation and
possible
attempted
retrieval.
locating the
retained
fragment
through
panoramic and
computed
tomographic
(CT) scanning.
A surgeon in
the operating
theater then
removes the
retained
needle
fragment while
the patient is
under general
anesthesia

9. 2. Prolonged anesthesia or paresthesia
•Prolongedanesthesiaorparesthesiamayoccurfollowingdental
localanestheticblocks.Thismaybetemporary,whereaftera
fewdays,weeks,ormonths,sensationreturnsoritmaybe
permanent.
•Thiscomplicationmostlyinvolveslingualorinferioralveolar
nerve.

10. •Paresthesiais defined as persistent anesthesia
(anesthesia well beyond the expected duration), or
altered sensation well beyond the expected duration of
anesthesia.
•A patient's clinical responseto this can be profuse and
varied, including sensations of numbness, swelling,
tingling, and itching.

11. Nerve may
be
damaged
during
injection
by direct
injury.
Hemorrhage
into or
around the
neural
sheath is
another
cause.
Neurotoxicity
of the local
anesthetic is
another
theory for
nerve
damage.
Procaine and
tetracainecause
more damage
than
bupivacaine or
lidocaine.
Injection of
local
anesthetic
solutions
contaminat
ed by
alcohol or
sterilizing
solutions
near a nerve
produces
irritation,
resulting in
edema and
increased
pressure in
the region of
the nerve.
Causes

12. I.Paresthesia,duetoanumbfeelingthepatientmayhave
discomfortsuchastonguebiting,drooling,lossoftaste(if
involvelingualnerve),andspeechimpediment.
II.Hyperesthesia??
III.Dysesthesia??
Problems

13. Strict adherence to injection protocol and proper care and handling
of dental cartridges help minimize the risk of paresthesia.
Deposit a drug (e.g., local anesthetic) as close to a nerve as possible
without actually contacting it.
Avoiding high concentration of anesthetic agent for inferior alveolar
nerve blocks (use 2% lidocaineas standard).
Prevention

14. Most paresthesiasresolve within approximately 8 weeks
without treatment.
•Reassurethe patient and explain that paresthesiais not
uncommon after local anesthetic adminstration.
•Examinethe patient (follow up).
•The use of a low daily dose of multivitamin B, to regaining nerve
healing and function, has been recommended.
Management

15. 3. Facial nerve paralysis
The seventh cranial nerve carries motor impulses to the
muscles of facial expression, of the scalp and external ear, and
of other structures.
Based on the time elapsed, from the moment of the injection
to the onset of the symptoms,the paralysis could be either
immediate or delayed.

16. Branches of facial nerve

17. Anatomical location of facial nerve
The facial nerve trunk liesapproximately 1 cm above and parallel to
the upper border of thedigastric musclenear its insertion at the
mastoid tip.

18. Cause Transient facial nerve paralysis
It is commonly caused by
the introduction of local
anesthetic into the
capsule of the parotid
gland, which is located at
the posterior border of the
mandibular ramus
Facial nerve palsy is a
complication of which
techniques??

19. Itlastsnolongerthanseveralhours,dependingon???
1.Cosmetic:thepatient’sfaceappearlopsided.
2.Thepatientisunabletovoluntarilycloseoneeye.Theprotective
lidreflexoftheeyeisabolished.
Problems

21. 1.Reassurethepatient.
2.Aneyepatchshouldbeappliedtotheaffectedeyeuntilmuscle
tonereturns.Ifresistanceisofferedbythepatient,advisethe
patienttomanuallyclosetheaffectedeyelidperiodicallytokeep
thecornealubricated.
Prevention?
Management

22. 4. Trismus
•Trismus, is defined as a prolonged, tetanic spasm of the
jaw muscles by which the normal opening of the mouth
is restricted.

23. •Trauma to muscles or blood vesselsin the infratemporalfossa is the
most common causative factor in trismus.
•Local anesthetics have been demonstrated to be slightly myotoxic
to skeletal muscles. The injection of local anesthetic solution
intramuscularly or supramuscularlyleads to a rapidly progressive
necrosis of exposed muscle fibers
Causes

24. Other causes of trismus
•Multiple needle penetrations correlate with a greater incidence of
post-injection trismus
•Excessive volumes of local anesthetic solution deposited into a
restricted area produce distention of tissues.
•Hemorrhage
•infection

25. 1.Useofsharp,sterile,disposableneedle.
2.Useaseptictechnique.Contaminatedneedlesshouldbechanged
immediately.
3.Practiceatraumaticinsertionandinjectiontechnique.
4.Useminimumeffectivevolumesoflocalanesthesia.
5.Avoidrepeatinjectionsandmultipleinsertionsintothesame
area??
Trismusisnotalwayspreventable.
Prevention

26. •Heat therapy (applying hot, moist towels to the affected area for
approximately 20 minutes every hour).
•Warm saline rinses.
•Analgesics.
•If necessary muscle relaxants (Diazepam 10 mg).
•Physiotherapy(for 5 minutes every 3 to 4 hours).
•Chewing gum (providing lateral movement of the
temporomandibularjoint).
Management

27. 5. Soft tissue injury
Self-inflicted trauma to the lips and tongue is
frequently caused by the patient inadvertently
biting or chewing these tissues while still
anesthetized.

29. Problem
•Trauma to anesthetized tissues can lead to swellingand significant
painwhen the anesthetic effects resolve.
•The possibility of infectionwill develop in most instances.

30. Infection of lower lip

31. •Alocalanestheticofappropriatedurationshouldbeselectedif
dentalappointmentsarebrief.
•Acottonrollcanbeplacedbetweenthelipsandtheteethif
theyarestillanesthetizedatthetimeofdischarge.
•Warnthepatientandtheguardianagainsteating,drinkinghot
fluids,andbitingonthelipsortonguetotestforanesthesia.
Prevention

32. 1.Analgesics ?
2.Antibiotics?
3.Warm saline rinses to aid in decreasing any swelling if
present.
4.Petroleum jelly or other lubricant
( to cover a lip lesion and minimize irritation).
Management

33. 6. Hematoma
•The effusion of blood into extravascular spaces can be caused by
inadvertent nicking of a blood vessel (artery or vein) during
administration of local anesthetic.
•A hematoma that develops subsequent to the nicking of an artery
usually increases rapidly in size ?
(because of the significantly greater pressure of blood within an artery).
Nicking of a veinmay or may not result in the formation of a
hematoma.

34. •Why hematoma rarely develops after a palatal
injection?
✓Because of the density of tissue in the hard palate and
its firm adherence to bone.
•While large hematoma developed after a posterior
superior alveolar or inferior alveolar nerve block?
✓The tissues surrounding these vessels more readily
accommodate significant volumes of blood. The blood effuses
from vessels until extravascular exceeds intravascular pressure,
or until clotting occurs.

35. •Trismus
•Pain
•Swelling
•Discoloration of the region
•Usually subside gradually over 7 to 14 days.
Complications
or problems

36. 1.Knowledge of the normal anatomy. Certain techniques are
associated with a greater risk of visible hematoma. (e.g.,ThePSA
nerve block is the most common, followed by the IANB then the
mental/incisive nerve block )
2.Minimize the number of needle penetration.
3.Use a short needle for the PSA nerve block to decrease the risk
of hematoma.
Hematoma is not always preventable
Prevention

37. ❖Immediate
•Whenswellingbecomesevidentduringorimmediately
afteralocalanestheticinjection,directpressureshould
beappliedtothesiteofbleedingfornotlessthan2
minutes.
Management

38. •Inferior alveolar nerve block
Hematoma will be visible
intraorallyincluding tissue
discoloration and probable
swelling on medial aspect of
ramus
Pressure is applied to
the medial aspect of
mandibular ramus

39. Anterior superior alveolar nerve block.
Pressure is applied to
the skin directly over
the infraorbital
foramen
Discoloration of the
skin below the lower
eyelid

40. ❑Hematoma is unlikely to occur with anterior superior
alveolar (ASA) nerve block?
✓because the technique described requires application
of pressure to the injection site throughout drug
administration and for a period of at least 1 to 2
minutes.

41. Incisive (Mental) nerve block
•Pressure is applied directly??
Over the mental foramen externally or intraorallyin the
mucous membrane
•Discoloration?
The skin of the chin and/or swelling in the mucobuccalfold

42. •Minimizes the risk of hematoma
formation during incisive (but not
mental) nerve block???

43. •Buccalnerve block or any palatal injection
Hematoma usually
are visible only
within the mouth
Place pressure
at the site of
bleeding

44. Posterior superior alveolar nerve block
•In this technique of anesthesia the largest and most esthetically
unappealing hematoma may occur. A colorless swelling will appear
on the side of the face around the temporomandibularjoint area
few minutes after injection is completed
•So how can you treat it?

45. 1-Itisdifficulttoapplypressuretothesiteofbleeding,why?
2-Bleedingnormallyceaseswhenexternalpressureonthevessels
exceedsinternalpressure,orwhenclottingoccurs.
3-Digitalpressurecanbeappliedtothesofttissueinthe
mucobuccalfoldasfardistallyascanbetoleratedbythepatient
withoutelicitingagagreflex
4-Ifavailable,iceshouldbeappliedextra-orallyto???

46. Do not apply heat to the area for at least 4 to 6 hours after the
incident of hematoma?
✓Heat produces vasodilation, which may further increase the size of
the hematoma if applied too soon.
✓Heat may be applied to the region beginning the next day. It
serves as an analgesic, and its vasodilatingproperties may
increase the rate at which blood elements are resorbed.
✓The patient should apply warm moist heat to the affected area for
20 minutes every hour.
Instructions

47. •Ice may be applied to the region immediately on recognition
of a developing hematoma?
✓It acts as both an analgesic and a vasoconstrictor, and it may
aid in minimizing the size of the hematoma.
✓With or without treatment, a hematoma will be present for 7
to 14 days.

48. 7.Ocular complications
•Diplopia (double vision)
•Blurred vision
•Amaurosis(temporary blindness)
•Mydriasis(papillary dilatation)
•Retrobulbarpain
•Miosis (papillary
restriction)
•Enophthalmos (recession of
the eyeball within the
orbit. have also been
reported after maxillary
and mandibular anesthesia.

49. Ocular complications
❑Prevention:
•Aspiration before injection
•inject slowly
❑Treatment:
1-Reassure the patient (this complication transient)
2-Cover the affected eye with gauze dressing
3-Referee the patient to an ophthalmologist for evaluation if last
more than 6 hours

50. Diplopia (double vision)

51. 8. Pain on injection
Causes:
I.Carelessinjectiontechnique.
II.Dullneedlebecauseofmultipleinjection.
III.Rapiddepositionoflocalanestheticsolution.

52. Problem
Increases patient anxiety
Sudden unexpected movement
Increasing the risk of needle breakage
Traumatic soft tissue injury to the patient
Needle-stick injury to the administrator.

53. •Prevention
1.Propertechniqueofinjection.
2.Usesharpneedles.
3.Usetopicalanesthesia.
4.Injectthesolutionslowly.
5.Makecertainthattemperatureofthesolutioniscorrect(A
solutionthatistoohotortoocoldmaybemore
uncomfortablethanoneatroomtemperature).

54. 9. Burning on injection
Causes:
I.TheprimarycauseisthePHofthesolutionbeinginjected,
solutionswithvasoconstrictorsaremoreacidic,theycause
morepainthansolutionswithoutvasoconstrictors.
II.Rapidinjection,especiallyinthedenser,moreadherent
tissuesofthepalateproducesmoreburningsensation.
III.Contaminationofthelocalanestheticcartridge.

55. 10.Infection
Infection subsequent to local anesthetic administration is an
extremely rare occurrence since sterile disposable needles
and glass cartridges have been introduced.
The major cause of post injection infection: is contamination
of the needle before administration of the anesthetic.
Contamination of a needle always occurs when the needle
touches mucous membrane in the oral cavity.
improper tissue preparation for injection are other possible
causes of infection.

56. 11. Sloughing of tissues
•Prolongedirritationorischemiaofgingivalsofttissuesmaylead
toepithelialdesquamationandsterileabscess.
•Causes:
1-Epithelialdesquamationcanbecausedeitherbecauseof
applicationoftopicalanesthesiaforprolongedperiodorbecause
highsensitivityofthetissuestoeithertopicalorinjectablelocal
anesthetic.

57. 2.Sterileabscesscanbecausedsecondarytoprolongedischemia
resultingfromtheuseoflocalanestheticwithvasoconstrictor,
usuallydevelopsonthehardpalate.
Management:
Usually,noformalmanagementisnecessaryforepithelial
desquamationorsterileabscess.Becertaintoreassurethe
patientofthisfact.

58. Management if symptomatic:
•For pain, analgesics such as aspirin or other NSAIDs and a
topically applied ointment (Orabase) are recommended to
minimize irritation to the area.
✓Epithelial desquamationresolves within a few day
✓Sterile abscess may run 7 to 10 days.

59. 12.Post anesthetic Intraoral Lesions
•Patients occasionally report that approximately 2 days after an
intraoral injection of local anesthetic, ulcerations developed in
their mouth, primarily around the site(s) of the injection.
✓Recurrent aphthousstomatitis or herpes simplex can occur intra-
orally after a local anesthetic injection .

60. ✓Cause of Post anesthetic Intraoral Lesions:
Trauma to tissues bya needle, a local anesthetic solution, a cotton
swab, or any other instrument (e.g., rubber dam clamp, handpiece)
may activate the latent form of the disease process that was present
in the tissues before injection

61. Systemic complications of local
anesthesia
Lec-9
3
rd
stage

Dr. Sairan khurshed
B.D.S., M.Sc. Oral Surgery

62. Systemic complications of local anesthesia
Overdose Allergy

63. 1.Overdose
Overdose reactions are those clinical signs and symptoms that
manifest as a result of over administration of a drug, which leads to
elevated blood levels of the drug in its target organs (places in the
body where the drug exerts a clinical action).

64. Signs and symptoms Overdose Levels:
It includeagitation, confusion, dizziness, drowsiness, dysphoria,
auditory changes, tinnitus, perioral numbness, metallic taste, and
dysarthria. Without adequate recognition and treatment, these signs
as symptoms can progress to seizures, respiratory arrest, and/or
coma.

65. Undernormalconditions,bothconstantabsorptionoflocal
anestheticfromthesiteofdepositionintothecardiovascularsystem
andconstantremovalofthedrugfromthebloodbytheliveroccur.
Localanestheticlevelsinthebloodremainlowandbelowthe
thresholdforoverdose.

66. Predisposing Factors for over
dose
Patient
Factors
Drug
Factors

67. 1.Age
2.Weight
3.Other drugs (Antidysrhythmic, Trycyclic antidepressant).
4.Sex
5.Presence of disease
6.Genetics ( Genetic deficiency in the enzyme serum
pseudocholinesterase).
7.Mental attitude and environment
Patient Factors:

68. Age
The functions of absorption, metabolism, and excretion may be
imperfectly developed in very young persons and may be diminished in
older-old persons, thereby increasing the half-life of the drug, elevating
circulating blood levels, and increasing the risk of overdose.
Weight:
Maximum recommended doses (MRDs) of local anesthetics normally
are calculated on the basis of milligram of drug per kilogram or pound
of body weigh

69. Sex
During pregnancy, renal function may be disturbed, leading to impaired
excretion of certain drugs, their accumulation in the blood, and
increased risk of overdose.
Presence of Disease
Hepatic and renal dysfunction impairs the body's ability to break down
and excrete the local anesthetic, leading to an increased anesthetic
blood level and increasing the risk of overdose.

70. Genetics
✓A genetic deficiency in the enzyme serum pseudocholinesterase .
This enzyme, produced in the liver
✓It is responsible for biotransformation of the ester local anesthetics.
A deficiency in this enzyme can prolong the half-life of an ester
local anesthetic, thereby increasing its blood level.
Mental Attitude and Environment
The apprehensive patient (experiencing pain when gentle pressure is
applied) is more likely to receive a larger dose of local anesthetic,
which would lead to increase risk of local anesthetic overdose.

71. I.Vasoactivity
II.Concentration
III.Dose
IV.Route of administration
V.Rate of injection
VI.Vascularity of the injection site
VII.Presence of vasoconstrictors
❖Drug Factors:

72. Vasoactivity:
All local anesthetics used by injection in dentistry are vasodilators. This
leading to an increased rate of drug absorption from the site of
injection into the cardiovascular system.
This causes two undesirable effects:
1- A shorter duration of clinical anesthesia
2- An increased blood level of the local anesthetic.

73. Dose:
The larger the volume of a local anesthetic administered, the higher the
resulting circulating blood level.
Concentration:
The greater the concentration (percent solution injected) of the local
anesthetic administered it cause greater the circulating blood volume of
the drug in the patient.

74. Route of Administration Local anesthetics:
A factor in local anesthetic overdose in dentistry is “inadvertent”
intravascular injection. Extremely high drug levels can be obtained
in a short time, leading to serious overdose reactions.
Rate of Injection
Slow (60-second or more) injection of LA produces significantly lower
levels in the blood, with a lesser risk that a severe overdose reaction will
develop.

75. Presence of Vasoconstrictors:
The addition of vasoconstrictor to a local anesthetic produces a
decrease in the perfusion of an area and a decreased rate of systemic
absorption of the drug. This, in turn, decreases the clinical toxicity of
the local anesthetic
Vascularity of the Injection Site:
The greater the vascularity of the injection site, the more rapid the
absorption of the drug from that area into the circulation.

76. 2. Allergy
Allergy is a hypersensitive state, acquired through
exposure to a particular allergen (a substance capable of
inducing altered bodily reactivity), re-exposure to which
produces a heightened capacity to react.

77. I.Fever
II.Angioedema
III.Urticaria
IV.Dermatitis
V.Depression of blood-forming organs
VI.Photosensitivity
VII.Anaphylaxis
Clinical manifestations of allergy vary and
include the following:

78. Overdose reactions are dose related .
a large enough amount of the drug must be administered to result in
excessive blood levels in the drugs target organ(s).
Difference between overdose and allergy reaction
By contrast, allergic reactions are not dose related. Whereas a
minuscule amount (e.g., 0.1 mL or less) of a drug to which the patient is
allergic can provoke life-threatening anaphylaxis.

79. 1. Preliminary medical evaluation should be completed before
administration of any local anesthetic.
2. Anxiety, fear, and apprehension should be recognized and
managed before administration of a local anesthetic.
3. All dental injections should be administered with the patient
supine or semi-supine.
Systemic complications are frequently
preventable by:

80. 4. Topical anesthetic should be applied before all injections for a
minimum of 1 minute.
5. The weakest effective concentration of local anesthetic solution
should be injected at the minimum volume compatible with
successful pain control.
6. The anesthetic solution selected should be appropriate for the
dental treatment (duration of action).

81. 7. Vasoconstrictors should be included in all local anesthetics unless
specifically contraindicated(e.g.,cardiovascular disease).

8. Needles should be disposable, sharp, rigid, capable of reliable
aspiration
9.Aspirating syringes must always be used for all injections.

10. Injection should be made slowly, over a minimum of 60 seconds
11. Observe the patient both during and after local anesthetic
administration for signs and symptoms of undesirable reaction.