local anesthesia complications Flashcards
other complications
1) intravascular injection
2) tissue blanching
3) postoperative discomfort
4) auricular disturbances
5) ocular disturbances
6) excessive spread of analgesia
symptoms
1) persistent numbness
- analgesia, dysesthesia, pruritis, hypoesthesia, hyperesthesia
2) causes
- electric shock
- alcohol or sterilizing solution may be toxic to nerve
initial response of paresthesia
1) always speak directly doctor to patient
2) sympathy, reassurance, document conversation
3) follow up exam
- determine degree (diagram geography and extent)
- inform patient: solution is waiting it out
- many instances self resolve in a few days, weeks, months
- permanent loss is rate
4) reexamine at 1 month intervals
special pencil
1) marking where the paresthesia is
when injury does occur
1) you can pass the lingual nerve and possibly amage it?
2) 94% recover in 2-12 weeks
- 5% in 9 months
- up to 10% of remaining injuries will never recover
hematoma
1) definition
- effusion of blood into extravascular spaces
2) presentation
- may be apparent during or after treatment as swelling/bruising
3) may be confused with edema, may cause trismus, develop infection, may cause paresthesia
hematoma treatment
1) pressure, ice for first several hours
2) follow on treatments
- heat to carry away / absorb trapped blood and byproducts
- APAP first 24 hours
- NSAIDS post 24 hours
trismus
1) jaw muscles are sore
2) limited range of motion
3) caused by injection into muscle and hematoma involving muscles of mastication, low grade infection, multiple injections
trismus treatment
1) on initial exams, record ROM for later comparison
2) open until it hurts, then go a little further
3) heat, warm saline rinses, analgesics, self-physiotherapy
4 )if no relief in 48 hours, prescribe antibiotics
facial nerve paralysis
1) paresis of muscles of facial expression
2) muscle droop, inability to close eyelid, other
3) causes
- anesthetizing the motor component of a facial nerve
- usually associated with infraorbital nerve block, MX cuspid infiltrations, PSA, all mandibular block techniques
facial nerve paralysis management
1) tape the eye, and use gauze
2) reassure patient that it is temporary
edema
1) swelling and looks like hematomas
2) can occur with or without pain
edema management
1) when produced by trauma, it self resolves
2) if edema threatens to compromise airway, treat as an emergency
- ABC
- call 911
- antihistamines, epi pen
3) if edema is infection, treat with antibiotic
- fluctuant is drainable
- cellulitis is not drainable
infection
1) post injection pain and swelling, sometimes leading to trismus
2) contaminated needle from oral mucosa contact
3) needle passing through existing infected tissue
4) osteomyelitis from intraosseous injections
needle breakage
1) can cause trismus for life
2) use larger gauge
- 25 and 27 gauge
3) never insert to the hub
4) do not bend, force needle
5) be aware of sudden patient movement
needle breakage management
1) remain calm
2) instruct patient to hold still and keep mouth open
3) extract with hemostat (no no proceed with incision and probing)
4) keep the fragments
comfort matters
1) painless injection and painless visit
- how patients judge you
three types of injection pain
1) needle stick
2) needle advancement
3) anesthetic deposition
gate theory
1) if a large nerve is stimulated, it closes the gate and inhibits the small nerve sensation
- pressure, movement, vibration
- overrides sensation of pain
warming
1) if the anesthetic is cold, they can feel the temperature change
injection speed
1) 2 ml over 60 seconds or rapidly over 15 seconds
- significantly more comfortable going slower
- also improve IA block sucess
needle size
1) for pain, it doesnt matter
2) matters for deflection
- 30 gauge deflects the most
injection pain
1) inject - wait - inject with anesthetic of choice
2) plain - then - vasoconstrictor
—
pros
1) perceived as making 2nd injection more comfortable
2) plain 1st helps address acidity of anesthetic
—
cons
1) both types require two needle sticks vs one
2) inject - wait - inject shallow
3) plain - then- vaso - ???
topical anesthetic
1) hurricane, EMLA, compounded
2) pros
- perceived as making needly stick more comfy, placebo and sense of care
3) cons
- 1-2 minutes
- analgesia very shallow (1-2 mm)
- tastes awful
buffer local anesthetic
1) dental anesthetic is highly acidic
- formulated with HCl
- preservative and vasoconstrictors add to acidity
- acidity extends shelf life
2 )if buffering, you can raise pH to 7.4 and cause H+ to fall off
- create 8000x more active form of anesthetic
- reduce injection pain (CO2 shuts down impulse)
- possibly help anesthetize inflammed tissue
iatrogenic damage
1) chewing on self
2) watch me stickers
top ten
1) facial nerve paralysis
2) needle breakage
3) injection pain, burning on injection
3 principles concerning effects of drugs
1) hepatic dysfunction
2) congestive heart failure
- decrease perfusion
3) renal dysfunction - impairs excretion
5 causes of elevated blood levels in LA
1) overdose
2) intravascular injection
3) absorptions rapid
4) slow biotransformation
5) slow removal
prepare
1) review med history
2) choice of anesthetic
3) calculate MRD
4) volume of LA administered
5 )LA administered to all four quadrants at one time
6) never get close to MRD
overdose of local anesthetic
1) mild - talkative, excited, irritable, sweating, elevation of vitals
2) moderate to severe
- seizure
- shut down CNS depression of BP, HR, RR
systemic toxicity treatment
1) GET THEM ON OXYGEN ASAP
2) ABCs
3) call 911
vasopressors
1) epinephrine or levonordefrin
2) benefits
- inhibit local vasoconstriction
- limit systemic uptake
- lower toxicity (safer)
- reduce bleeding
- increase depth of numbness
epinephrine sensitivity
1) tachycardia, palpitations, sweating, nervousness, all symptoms of anxiety
2) signs of allergy
- skin reactions, sneezing, redness of eyes,
- dyspnea, and anaphylaxis
vasopressors require anti-oxidant / preservative in formulation
1) sodium metabisulfite
2) potassium metabisulfite
3) allergic reactions to preservatives (rare)
- respiratory reactions in asthmatics
- individuals with sulfa drug allergies are OK
- individuals with food allergies to sulfites: rash, hives, anaphylaxis, use plain anesthetics
at risk groups
1) HTN >200/115
2) pregnancy
3) uncontrolled hyperthyroidism
4) significant cardiac dysrhythmias
5) severe cardiovascular disease
- daily angina
recommendations for at risk groups
1) maximum dose with at risk adult 0.04 mg
2) aspirate multiple times
3) use mepivacaine?
drug interactions
1) tricyclic antidepressants
2 )cocaine!
pregnant and nursing patient
1) 1st trimester
- week 0-12
- avoid LA
- active infection may present higher risk than using LA
2) 2nd trimester
- week 13-24
- optimum time for dental treatment
- most obstetricians recommend no epinephrine
