The Trials and Tribulations of Local Anaesthesia: Tips on ... · The Trials and Tribulations of...

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The Trials and Tribulations of Local Anaesthesia: Tips on success and potential pitfalls [email protected] Professor Oral Surgery Kings College London President British Association of Oral Surgeons

Transcript of The Trials and Tribulations of Local Anaesthesia: Tips on ... · The Trials and Tribulations of...

The Trials and Tribulations of Local Anaesthesia: Tips on success and potential pitfalls

[email protected] Professor Oral Surgery Kings College London

President British Association of Oral Surgeons

AIMS; o To provide an overview of the patients perspective of dental LA o To discuss commonly used dental LA's and their potential side-effects. o To highlight problems with common dental LA injection techniques o To create awareness of different LA delivery protocols for common dental

procedures. OBJECTIVES; o Summarise the unwanted side effects of LA's o Minimise the risk of neurological damage. when giving LA's o Update the developing alternative LA injection techniques "

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TO STAY OUT OF JAIL!

• An update on pain • The patients perspective • Systemic issues for LA • Complications of LA • Failed LA • Avoiding LA nerve injuries • Update on LA techniques

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Outline

• An update on pain • The Patients perspective • Systemic issues for LA • Complications of LA • Failed LA • Avoiding LA nerve injuries • Update on LA techniques

Kings College London-Tara Renton

Outline

IASP definition of pain

An unpleasant sensory and emotional experience associated with actual or potential tissue damage, or described in terms of such damage

IASP definition of pain

An unpleasant sensory and emotional experience associated with actual or potential tissue damage, or described in terms of such damage

Pain is complex

• The great protector….. Sensory feedback for all cranial functions Brains- Consciousness + neural regulation Breathing Sight Smell Taste The face…the organ that underpins communication

Trigeminal nerve

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Trigeminal nerve

Your patient is programmed to run for the hills!!!!!!!!

4 types of pain

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• Nociceptive healthy feeling pain ‘pain’

• Inflammatory pain health short lived after insult

• Neuropathic pains

• Dysfunctional pain

Clifford J. Woolf. What is this thing called pain? J Clin Invest. Nov 1, 2010; 120(11): 3742–3744.

Operative pain

&Dentine

sensitivity

Healthy

nociceptive

pain

Clifford J. Woolf. What is this thing called pain? J Clin Invest. Nov 1, 2010; 120(11): 3742–3744.

Pulpitis reversible

+irreversible

Periapical

periodontitis

Healthy

inflammatory

pain/infection/t

Trauma

Chronic

neuropathi

c pain

Posttraumatic

neuropathy

PDAP/ PHN Dysfunctional

pain Fibromyalgia

PIFP

TMD arthromyalgia?

o Nociception

o Sensation/perception

o Behaviour

o Suffering

Social / Cultural

Age, gender, race, peer

support, familial expectation

Emotional / psychologic

al

Depression, anxiety,

stress, fear, anger

Cognitive / Conceptual

Memories past experience, secondary gain, threat perception

Bio psycho

social Model

Pain Process

Pain process

Depends upon the patient Nociception

Sensation

Behaviour

Suffering

Nociception

Sensation

Behaviour

Suffering

Management depends upon the patient

Nociception

Sensation

Behaviour

Suffering

Management depends upon the patient

But is painless dental surgery really possible???

Are we a Magician or Dental surgeon?

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LA blocks nociception

LA prevents any action potential and blocks nociceptive pain

Is NOT enough! +

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Perioperative dental pain is not managed well

• 73.4% of patients report pain during dental treatment

• A population study with 1086 individuals has shown that 42.5% reported pain during dental treatment

• Pain intensity was reported as mild, uncomfortable, moderate, severe or very severe by 20%, 35.1%, 33.3%, 8.2% and 3.4% of patients, respectively In some cases, severe pain was reported by 25% of patients.

• As to dental experience involving severe pain, 60% of a representative sample of general population aged 15 years or more have reported pain at least once

Locker D, Shapiro D, Liddell A. Negative dental experiences and their relationship to dental anxiety. Community Dent Health. 1996;63(1):86-92. [ Links ] Maggirias J, Locker D. Psychological factors and perceptions of pain associated with dental treatment. Community Dent Oral Epidemiol. 2002;30(2):151-9. [ Links ] Siviero M, Nhani VT, Prado EFGB. Análise da ansiedade como fator preditor de dor aguda em pacientes submetidos à exodontias ambulatoriais. Rev Odontol UNESP. 2008;37(4):329-36.

Lack of empathetic treatment

10-15% of patients felt poorly cared for

Adult Dental Health Survey 2009

How can we maximise patient comfort and minimise pain?

– Clinician Caring, Communication

• Correct diagnosis

• Patient relationship

• Empathy works

– Manage patients expectations

• Education pre and post op

• Frank consent

• Allow some patient control

– Anxiolysis -assess and manage

– Surgical technique – LA, analgesics

– Post op advice

• Accessibility for patient contact

• Analgesics clear advice Copyright www.orofacialpain.co.uk/newhome

Nociception

Sensation

Behaviour

Suffering

• An update on pain • The Patients perspective • Systemic issues for LA • Complications of LA • Failed LA • Avoiding LA nerve injuries • Update on LA techniques

Outline

Patient perspective - anxiety

• Common

• The dental anxiety was measured by Modified Dental Anxiety Scale. (MDAS).

Fotedar S, Bhardwaj V, Fotedar V. Dental anxiety levels and factors associated with it among patients attending a dental teaching institute in Himachal Pradesh. SRM J Res Dent Sci 2016;7:153-7

Anxiety is determinant for pain during dental care and pain is related to local anaesthetic procedures. There are evidences that dentists' attitudes are determinants for pain.

Vassend O. Anxiety, pain and discomfort associated with dental treatment. Behav Res Ther. 1993;31(7):659-66.

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Patient perspective Phobia • an extreme or irrational

fear of or aversion to something.

Dental phobia is the most common phobia

Fear of pain • Melanocortin 1 receptor def –Mu

opoid receptor def

• Need 20% 20% more anaesthetic

• Melanocortin-1 Gene for Red Hair

2002 “It does appear that redheads have a

significantly different pain threshold and

require more anaesthetic to block out certain

pains,”

2010 Danish study suggests red headed

people feel the cold more but could handle

eating hot food

Our role models don’t help!

There aren't many people (if any) who actually enjoy going to the dentist – but at least one in 10 are absolutely terrified of the experience. These people suffer from extreme dental anxiety – which is more common in women than men – and the British Dental Health Foundation (BDHF) says they're often particularly frightened of having a tooth drilled (30%) or a local anaesthetic injection (28%).

And patients like this are rare!

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Strategies to manage fearful anxious patients

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Reassurance Control Distraction Sedation oral, inhalational and IV indication for sedation need Hypnosis Acupuncture

Patient website Here are 10 ways to deal with your dental fears:

• 1. Find an understanding dentist. Ask friends and family if they can recommend one or look for someone who advertises themselves as an expert with anxious patients. You can search for your local dentists on the NHS’s online directory.

• 2. Relaxation methods including breathing techniques, muscle relaxation, self-hypnosis and visualisation can help.

• 3. Taking a friend and listening to music might help you relax.

• 4. Tell your dentist about your fears, and before treatment begins, agree a signal with him/her that means ‘stop’ in case you need a break.

• 5. The dental wand (a computer-driven injection system) is great for anyone with a needle phobia. A numbing gel can also be used to numb your gums before an injection.

• 6. If you're extremely nervous, ask your dentist to refer you to an NHS sedation clinic. Some people find inhalation sedation helpful, but truly terrified patients may prefer intravenous sedation (through an injection), which won’t knock you out – you’ll be awake and able to talk – but will deeply calm and relax you 7. Take a squashy object to hold and squeeze during treatment.

• 8. Concentrate on the external sounds in the dental surgery and things like the weight of your body on the chair, the texture of the armrest, etc. The idea is to focus outwardly to help you relax.

• 9. Ask the dentist to leave the chair upright if possible – some people feel more vulnerable lying down, which can increase anxiety.

• 10. Contact a support network such as Dental Phobia.

• http://home.bt.com/lifestyle/scared-of-the-dentist-10-ways-to-beat-your-phobia-11364013397424

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We can get it wrong! Showing videos as patient information to patients with previous negative dental experience …… Significantly increases anxiety !

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Psychological factors driving pain Sullivan MJ et al. Catastrophizing and perceived injustice: risk factors for the transition to chronicity after

whiplash injury. Spine (Phila Pa 1976). 2011 Dec 1;36(25 Suppl):S244-9 Dec;92(12):2041-56. Review

Lajnert V, et al Depression, somatization and anxiety in female patients with temporomandibular disorders

(TMD). Coll Antropol. 2010 Dec;34(4):1415-9

Alternative and holistic management of pain Bauer B et al. Effect of the combination of music and nature sounds on pain and anxiety in cardiac

surgical patients: a randomized study. Altern Ther Health Med. 2011 Jul-Aug;17(4):16-23.

Louw A, et al.The effect of neuroscience education on pain, disability, anxiety, and stress in chronic

musculoskeletal pain. Arch Phys Med Rehabil. 2011

Reduced pain in two ways -- either by giving them a placebo, or a difficult memory task. lacebo. But

when they put the two together, "the level of pain reduction that people experienced added up. There was no interference between them, Jason T. Buhle, Bradford L. Stevens, and Jonathan J. Friedman and Tor D. Wager.Distraction and Placebo: Two Separate Routes to Pain Control. Psychological Science, 2012

Placebos, Lacebos decrease Anxiety, stress and pain

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ANXIETY FEAR STRESS PAIN THRESHOLD PAIN EXPERIENCE

Minimising pain during injection Distraction techniques

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Care in your LA technique!

• Reassurance/ warnings • Give your patient feeling of control • Distraction • Topical LA • Place finger tip near region where your about

to inject • Warm LA cartridges • Slow = painless • Avoid showing patient the syringe!

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A key factor in patient satisfaction is a sense that the caregiver is doing their best and is genuinely concerned that therapy is adequate.

(Bucknall, Manias, & Botti, 2007).

• An update on pain • The patients perspective • Systemic issues for LA • Complications of LA • Failed LA • Avoiding LA nerve injuries • Update on LA techniques

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Outline

Get the diagnosis right

LA Systemic complications

• 2731 patients dental LA in Germany • 45.6% pts had medical risk factors (mostly cardiovascular) • Overall 4.5% complications (5.7% in risk pts) non risk patients 3.5% • Most common dizziness, tachycardia, agitation, bronchospasm • Severe seizures, bronchospasm (0.07%) • Less complications with Articaine 4% I:100K epinephrine compared

with Articaine 4% I:200K epinephrine • Dose of anaesthesia variable

• Adverse effects are usually caused by high plasma concentration

of LA drug resulting from

– Inadvertent intravascular injection

– Excessive dose or rate of injection

– Delayed drug clearance

– Medically compromised patients

– Drug interactions

LA Systemic effects Avoid high dose

Incidence of Adverse Reactions

• Over 800 million dental local anaesthetic injections are given annually worldwide

• The adverse reaction rate is 1:1,000,000

• Mortality (death) rate from dental local anaesthetic injections has been

stated at 0.000002%*

• Allergies are very rare and can often be psychosomatic

“A study by Dundee Dental School showed that of 27 cases of “local anaesthetic

allergies”, only one was caused by the anaesthetic injection (and this was a

sulphite allergy, not a drug allergy)”

* Harris SC (1957) Aspiration before injection of dental local anaesthetics J Oral Surg;15:299-303

LA complications

LA COMPLICATIONS = CONCENTRATION & DOSE of LA

VS SIZE & HEALTH of patient

The one tenth of a cartridge per kilogram rule

OR 1 cartridge per 10Kg

Maximum doses

Drug Max dose 1/10th cartridge

2% lidocaine 4.4mg/kg 3.6 - 4.4mg

2%

mepivacaine

4.4mg/kg 4.0mg

3%

mepivacaine

4.4mg/kg 6.0 mg

3% prilocaine 6.0mg/kg 6.6mg

4% prilocaine 6.0mg/kg 8.0mg

4% articaine 7.0mg/kg 6.8 - 8.0mg

LA complications

Adult toxic doses Lignocaine and epinephrine 11 Cartridges Prilocaine and felypressin 4 Cartridges Articaine and epinephrine 7 Cartridges Bupivicaine with epinephrine 10 Cartridges Very difficult to reverse due to high protein binding capacity

Overdose Systemic effects Lidocaine

• When plasma levels are usually 3-5 mcg/mL

• Toxicity may be observed at 6 mcg/mL, but more likely above10 mcg/mL

• Additional factors increasing toxicity are;

– Site of injection

– Hepatic, cardiac and renal failure

– Speed of injection

– Hypo proteinaemia

– Acidosis

• Potential Drug interactions

Overdose Lidocaine toxicity • At serum levels patients may complain of; • 1-5 mcg/mL

– Tinnitus – Lightheadedness – circumoral numbness – Diplopia – metallic taste – may complain of nausea and/or vomiting, or they may become more talkative.

• 5-8 mcg/mL – nystagmus, slurred speech, localized muscle twitching, or fine tremors may be noticed.

Patients also have been noted to have hallucinations at these levels.

• 8-12 mcg/mL – focal seizure activity occurs; this can progress to generalized tonic-clonic seizures. Respiratory

depression occurs at extremely high blood levels (20-25 mcg/mL) and can progress to coma.

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Be careful with ‘small’ patients Kids &

older frail patients!

Ageing patient

• Ageing men lose muscle mass, typically about 0.5- 1.0% per year after the age of 40.

• By the age of 50 up to roughly a 5-10% loss in muscle mass.

• Additionally, this loss in muscle mass is typically accompanied by an increase in fat mass, especially abdominal fat.

The term for the age-related decline in muscle mass is sacropenia. According to one study, approximately one in every two men over the age of 60 suffer from moderate sacropenia.2 Sacropenia causes a decrease in metabolism and a loss in functional strength.

Be careful with kids!

Child of 5 years -weighs 18 - 20kg- maximum dose 88mg (2 x 2.2ml Lidocaine cartridges)

Lidocaine toxicity symptoms - KIDS At serum levels patients may complain of;

• 1-5 mcg/mL

– Tinnitus

– Lightheadedness

– circumoral numbness

– Diplopia

– metallic taste

– may complain of nausea and/or vomiting, or they may become more talkative.

• 5-8 mcg/mL

– nystagmus, slurred speech, localized muscle twitching, or fine tremors may be noticed. Patients also have been noted to have hallucinations at these levels.

• 8-12 mcg/mL

– focal seizure activity occurs; this can progress to generalized tonic-clonic seizures. Respiratory depression occurs at extremely high blood levels (20-25 mcg/mL) and can progress to coma.

Goodson and Moore have documented catastrophic consequences of this drug interaction in pediatric patients receiving procedural sedation, along with excessive dosages of local anesthetics. Goodson JM, Moore PA. Life-threatening reactions after pedodontic sedation: an assessment of narcotic, local anesthetic and antiemetic drug interactions. J Am Dent Assoc. 1983;107:239–245.

Minimise toxicity

– Avoid injection intra-vascularly (USE ASPIRATION) and intraosseously

– Be aware of increased vascularity of inflamed tissue

– Observe clinical reactions: • Talk to the patient and monitor ECG/blood pressure to realize early

symptoms of central-nervous and cardiovascular toxicity

• Stop injection immediately when early symptoms are realized

• Consider the time course for development of toxic signs (5-10 min)

• Long acting and potent substances: dangerous! Bupivacaine („Fast in, slow out“)

Tips to Avoid LA systemic problems by not……

• Risk factors LA overdose – All 4 quadrant treatment (staged treatment for elderly patients) – Plain LA (no vasoconstrictor) – Full cartridge injections (should commonwealth move to 1.8ml cartridges?) – Exceeding maximum dose

• Prevent overdose – Aspirate – Slow injection – Dose vs Size of patient – Excretion

Medical Modifiers for LA

Medical Modifiers Pregnancy

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• Slow low volume injection Lidocaine +epinephrine OK

• Aspirate!

Medical Modifiers Hypertension

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Hypertension Systolic >200 <6 months MI or stroke or bypass Uncontrolled Hyperparathyroidism Brittle angina No issues with hypertension as long as infiltration or blocks with aspiration BUT

Medical Modifiers Haemorrhagic disorders

• Avoid block if possible

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Systemic effects of epinephrine occur at normal

doses?

blood glucose epinephrine

K+

Medical modifier Diabetes epinephrine effects

Avoided with aspiration...legal requirement!

Medical Modifiers Renal Excretion

• Keep in mind that both liver and renal functions decline 50% by age 65.

• Also, beta blockers reduce hepatic blood flow, and this may prolong the elimination of amide local anaesthetics.

• Articaine is the exception because it has an ester side chain and is inactivated in serum by plasma cholinesterases.

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Montamat SC, Cusack BJ, Vestal RE. Management of drug therapy in the elderly. N Engl J Med.1989;321:303–309

Medical Modifiers Poor Clearance or compromised hepatic function

• Aspiration

• Slow low volume injection Lidocaine + epinephrine OK (>8 seconds application)

• Aspirate!

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Essentially if the patient can walk into dental surgery………

There is no contraindication to use epinephrine (with aspiration) but…. Recreational use of cocaine by patients can increase the risk of blood pressure and cardiac arrhythmias with injectable anaesthetics.

Medical modifiers Cardiac

Finder RL, Moore PA. Adverse drug reactions to local anesthesia. Dent Clin North Am Oct. 2002; 46(4):747-57.

Medical Modifiers Drug interactions • Lidocaine can interact with CNS depressants

• Lidocaine can interact with H2 Blocker (PPIs)

• Epinephrine – Propranolol is the only nonselective beta-blocker reported to have the

potential to cause severe hypertension and reflex bradycardia in the presence of epinephrine. A significant risk does not appear to be associated with the use of epinephrine and cardio selective beta-blockers.

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Medical Modifiers Methaemoglobinemia Methaemoglobinemia has been frequently reported in association with benzocaine use; lidocaine and prilocaine have also been implicated. At low levels (1-3%), methaemoglobinemia can be asymptomatic, but higher levels (10-40%) may be accompanied by any of the following complaints:

• Cyanosis • Cutaneous discoloration (gray) • Tachypnea • Dyspnea • Exercise intolerance • Fatigue • Dizziness and syncope • Weakness

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Myths Modifying factors-medical complications

You should avoid the use of adrenaline containing local anaesthetic in:

• Patients on Mono amine oxidase inhibitors

• All hypertensive patients

• All patients who have angina or had an MI

• All patients with liver disease

• Bilateral ID blocks are dangerous

• Citanest may induce labour in pregnant females

Barker SJ, Tremper KK, Hyatt J. Effects of methemoglobinemia on pulse oximetry and mixed venous oximetry. Anesthesiology. 1989;70:112–117. Becker DE, Reed KL. Local anesthetics: review of pharmacological considerations. Anesth Prog.2012;59:90–102

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Keep it simple Aspiration prevents most LA adverse events No brainer!

Standard Self-Aspirating

•The withdrawal by negative pressure of fluid from any cavity of the body

•A vital step when injecting an anaesthetic

•A legal requirement in UK

•Vasovagal • Allergy

• Other

Causes for Patient collapse

Signs of anaphylaxis

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Breathlessness- asthma symptoms bronchospasm throat swelling Rash-Urticaria itching Patient distress and awareness of feeling unwell Angioneurotic edema Abdominal cramping Irregular heart beat Hypotension Patient collapse

Anaphylaxis Patient collapse

Adult collapse = presumed cardiac arrest

• 1:1000 Units Epinephrine IM

• Oxygen

Get the defibrillator there

ASAP!

Every minute delay = 7% increase in

mortality rate

Systemic issues and LA

Causes of Allergy

Allergy may be due to

– Bung (Latex)

– Preservative

– Antiseptic

– Vasoconstrictor

– Local anaesthetic agent

LA complications

Esters are highly allergenic No documented allergy to amides Pt likely to be allergic to bisulphate preservative (needed for vaso-constricture). Least allergenic LAs are Mepivicaine or plain Prilocaine

What Causes Adverse Reactions?

71

LA Complications Adjuvant agents

•Sodium Metabisulphite, an ingredient added to buffer pH of adrenaline-

containing solutions •Citanest® brands do not contain sodium metabisulphite as Octapressin does not

need buffering

•Plain anaesthetics do not need buffering (Scandonest Plain)

•Latex allergy to parts of the cartridge bungs/ membranes •Products that contain natural rubber can be untreated or treated to reduce the risk

of allergy

•Treated latex is heated to >160°C to denature proteins that cause allergic

reaction

•Not certain it will prevent a reaction if the allergy is severe enough

All UK LA agents now Latex free?

Local anaesthetics NOT all latex free The product has not been tested for presence of latex – it is assumed, therefore, to contain latex UK Medicines Information (UKMi) pharmacists for NHS healthcare professionals Date prepared: January 2012

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Brand name Ingredients Presentation Company Ref

Lidocaine

Xylocaine* Lidocaine 2% with

adrenaline 1:80,000

2.2mL standard and 2.2mL

self-aspirating cartridge

Dentsply 10

Emla cream Lidocaine 2.5% and

prilocaine 2.5%

5g tube (with or without

dressings) AstraZeneca

11

Xylocaine spray Lidocaine 10% spray 50mL bottle 11

Tetracaine

Ametop gel Tetracaine 4% 1.5g tube Smith & Nephew

Healthcare

12

• An update on pain • The patients perspective • Systemic issues for LA • Complications of LA • Failed LA • Avoiding LA nerve injuries • Update on LA techniques

Kings College London-Tara Renton

Outline

Problems in the post-injection period

• Nerve injury

• Tissue trauma-haematoma trismus

• Facial palsy

• Ophthalmic complications

LA complication Local

Neurological complications to LA

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Complications of LA Trismus

• Rare due to haematoma formation in pterygoid muscles

• Usually related to haemorrhagic disorders or multiple injections

– Bleeding clotting disorders

– Short needle

– Avoid blocks

– Haematoma will disperse in 7-14 days

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Fractured Needle

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Ophthalmic complications LA

• Intravascular injections

• Maxillary artery and vein

• An update on pain • The patients perspective • Systemic issues for LA • Complications of LA • Failed LA • Avoiding LA nerve injuries • Update on LA techniques

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Outline

Effectivity of IDB

82

• Lip numbness = pulpal paraesthesia WRONG

• When evaluated in 123 patients using a standardized alveolar nerve block method, the block provided analgesia /anesthesia to the

– first molar (92%),

– first premolar (55.3%)

– canine (38.2%) teeth of the lower jaw.

TN Lai, CP Lin, SH Kok Evaluation of mandibular block using a standardized method Oral Surg Oral Med Oral Pathol Oral Radiol Endod, 102 (2006), pp 462 - 468

Actual pulpal anaesthesia rates using IDB!

•45-92%

•30-56%%

•28-45%

83 Meechan JG The use of the mandibular infiltration anesthetic technique in adults. J Am Dent Assoc.

2011 Sep;142 Suppl 3:19S-24S.

Failed IDB Local anesthesia

Malamed1 stated the rate of inadequate anaesthesia ranged from 31% to 81%. When expressed as success rates, this indicates a range of 19% to 69%. These numbers are so wide ranging as to make selection of a standard for rate of success for IANB seemingly impossible.

Supplemental infiltrations plus IDB 1st Molar

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Journal of Conservative Dentistry, Vol. 18, No. 3, May-June, 2015, pp. 182-186 Anesthetic success of supplemental infiltration in mandibular molars with irreversible pulpitis: A systematic review Seema Yadav

Failed LA possible reasons

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Failed LA Anatomy

• Broad angled jaw

• Take this into account when planning an IDB

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Tae Min You,1 Kee-Deog Kim,2 Jisun Huh,2 Eun-Jung Woo,2 and Wonse Park The influence of mandibular skeletal characteristics on inferior alveolar nerve block anesthesia J Dent Anesth Pain Med. 2015 Sep;15(3):113-119. English. 2015.

Failed LA Operator

Technique

• Infiltration

• Block

• Too fast

• Insufficient LA

• Patient non compliance

Equipment

• Inappropriate storage of LA

• Dose and type of LA

• Needle length

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Failed LA Pulpitis • This is a challenging clinical problem, and can only

be overcome by increasing the dose of anaesthetic in the area9, with increased accuracy of the placement of the anaesthetic solution.

• intra-ligamentary or intra-osseous approaches are most effective for this.

• In a number of patients careful probing will allow identification of a small bony canaliculus in the alveolar crestal bone, where it is possible to insert a fine (30/31g) needle, and instil the anaesthetic solution directly into the cancellous bone

• Patients should be warned of a brief sensation of palpitations as some anaesthetic solution will escape into the general vascular circulation. This also means that duration of anaesthesia will be limited, and is often no more than 20-30 minutes.

• In some cases, intra-pulpal injection of solution is possible, and usually is highly effective, although briefly painful;

• Articaine 4% infiltration may be helpful in these difficult cases10,11,12, although this may be inconsistent13, and also may be used as an infiltration palatal to an upper tooth, and buccal to a lower molar to supplement conventional approaches12.

• An increased dose of anaesthetic is typically required to achieve anaesthesia in these cases. Infiltrations or blocks typically require repeating, to achieve field anaesthesia, and it is often necessary to administer 0.75 – 1ml in the periodontal/intraosseous interface area to achieve anaesthesia.

• Meechan JG. How to overcome failed local anaesthesia. Br Dent J 1999; 186(1): 15-20

• Meechan JG. Articaine and lignocaine. Evid Based Dent. 2011;12(1):21-2

• Srinivasan N, Kavitha M, Loganathan CS, Padmini G. Comparison of anesthetic effi- cacy of 4% articaine and 2% lidocaine for maxillary buccal infiltration in patients with irreversible pulpitis. Oral Surg Oral Med Oral Pathol Oral Radiol Endod 2009;107:133–6.

• Kanaa MD, Whitworth JW, Corbett IP, Meechan JG Articaine buccal infiltration enhances the effectiveness of lidocaine inferior alveolar nerve block. Int Endod J 2009; 42(3):238-46

• Kanaa MD, Whitworth JW, Meechan JG. A Comparison of the Efficacy of 4% Articaine with 1:100,000 Epinephrine and 2% Lidocaine with 1:80,000 Epinephrine in Achieving Pulpal Anesthesia in Maxillary Teeth with Irreversible Pulpitis. J Endodon. 2012; 38(3): 279-282

• Kuriyama T, Absi E G, Williams D W, Lewis M A. An outcome audit of the treatment of acute dentoalveolar infection: impact of penicillin resistance. Br Dent J 2005; 198: 759–763.

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• 182 patients

• 122 achieved successful pulpal anesthesia within 10 minutes after initial IANB injection only 82 experienced pain-free treatment.

• Articaine buccal infiltration (ABI) and Intraosseous (IO) allowed more successful (pain-free) treatment

• IANB + ABI 84% pain free RX

• IANB + IO 68% pain free Rx

• IANB + PDL 48% pain free Rx

• IANB alone 32% pain free Rx

Irreversible Pulpitis Supplemental techniques

Kanaa MD, Whitworth JM, Meechan JG. J Endod. 2012 Apr;38(4):421-5. doi: 10.1016/j.joen.2011.12.006. Epub 2012 Feb 2. A prospective randomized trial of different supplementary local anesthetic techniques after failure of inferior alveolar nerve block in patients with irreversible pulpitis in mandibular teeth.

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• Improved levels of analgesia may be obtained by adding an Articaine buccal infiltration to the IANB. – Parirokh et al (2010) 65%

– Rogers et al (2009) 62%

– Kanaa et al (2009) 52%

Parirokh M, Satvati S A, Sharifi R, Rekabi A R, Gorjestani G, Nakhaee N, Abbott P V. Efficacy of combining a buccal infiltration with an inferior alveolar nerve block for mandibular molars with irreversible pulpitis Oral Surg, Oral Med, Oral Path, Oral Radiol and Endodontol 2010 109:3 468-473 Kanaa M D, Whitworth J M, Corbett I P, Meechan J G. Articaine buccal infiltration enhances the effectiveness of lidocaine inferior alveolar nerve block International Endondon. 2009 J 42 238-246 Rogers B S, Botero T M, McDonald N J, Gardner R J, Peters M C. Efficacy of Articaine vs Lidocaine as a supplemental buccal infiltration in mandibular molars with irreversible pulpitis: a prospective, randomised, double-blind study J.Endodod. 2014 40:6 753-758

Failed LA Infection • Existing infection? • Local acidity of the infected

tissue will reduce the effectiveness of the alkaline base LA agent

• Avoid spreading infection by injecting in or near the focus

• Be smart use regional block anaesthesia (Infra orbital, greater palatine)

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Failed LA Consider Infiltration first then IDB • If failed

• Supplemental Articaine buccal infiltration for pulpitic teeth

• OR

• Repeat Infiltration

• Repeat different technique IDB Gow Gates or Akinosi

• Some endodontists use 3% Mepivicaine after routine Lidocaine 2% block fails

Kings College London-Tara Renton

The Akinosi vs Gow gates

• Patient impossible to anaesthetise

– Articaine infiltrations buccally

– Repeat Lidocaine block

– OR Mepivacaine Gow gates or Akinosi

• And WAIT>>>>>>>>>>>!

LA Failure- alternate techniques

• An update on pain • The patients perspective • Systemic issues for LA • Complications of LA • Failed LA • Avoiding LA nerve injuries • Update on LA techniques

Kings College London-Tara Renton

Outline

96

Dental causes of TNI

97

LA nerve injuries

Why are nerve injuries such a big deal?

Kings College London-Tara Renton

Complex region

Consequences

Social function

Eating

Drinking

Speaking

Kissing

Make up / shaving

Sleeping

IDENTITY?

The Trigeminal nerve

LA nerve injury the patients perspective

IANI

LNI

95% of IRTNI patients have pain pain Queral-Godoy E, Vazquez-Delgado E, Okeson JP, Gay-Escoda C. Persistent idiopathic facial pain following dental implant placement: a case report. Int J Oral Maxillofac Implants 2006; 21: 136-40. Rodriquez-Lozano F, Sanchez-Perez A, Moya-Villaescusa MJ, Rodriguez-Lozano A, Saez-Yuguero MR. Neuropathic orofacial pain after dental implant placement: review of the literature and case report. OOOE 2010; 109: e8-e12. Renton T, Yilmaz Z. Profiling of patients presenting with posttraumatic neuropathy of the trigeminal nerve. J Orofac Pain. 2011 Fall;25(4):333-44. Renton T, Dawood A, Shah A, Searson L, Yilmaz Z. Post-implant neuropathy of the trigeminal nerve. A case series. Br Dent J. 2012 Jun 8;212(11):E17. doi: 10.1038/sj.bdj.2012.497

Numbness, pain & altered sensation

Impact on daily function

• Depression

• Anger

• Post traumatic stress disorder

• Victim of abuse

• Loss of ability to trust

• Kubler Ross

Psychological impact

So how do we avoid nerve injuries? Prevention is best as we cannot fix them!

Dentistry is the ONLY healthcare profession taught to aim for nerves blindly during block injections!

Possible Mechanisms of nerve injury • Chemical o Agent o Vasoconstrictor o Buffer o Preservative o Metabolites

• Mechanical o Epineural, endonerural, epi fascicular, endo fascicular o Direct /Indirect

• Haemorrhage • Chemical iron content very irritant to neural tissue • Primary or secondary haemorrhage/ scarring epi or intra neural • Infection

Extrafascicular administration of clinically used concentrations of local anesthetic solutions may alter perineurial permeability, causing endoneural edema, increasing endoneurial fluid pressure, causing Schwann cell injury and axonal dystrophy with endoneural fibrotic changes as a late consequence (Myer et al., 1986).

Increased perineural permeability, resultant edema, and pressures intrafascicles, the normally hypertonic endoneural fluid becomes hypotonic (Hogan, 2008). Thus, a local anesthetic solution applied non-traumatically and externally to a peripheral nerve bundle may cause deleterious effects by increasing intraneural hydrostatic pressure.

Hydrostatic pressure from injection, direct mechanical injury to the nerve by the needle, or chemical injury from the local anesthetic solution itself (Haas, 2006)

http://trigeminalnerve.org.uk/

How we injure nerves during LA? Mechanism of trauma Mechanical Direct needle/ indirect scarring

Pressure ischaemia from bleed or LA Chemical LA agent, buffer, preservative, carrier Haemaglobin (Fe irritates nerve)

Extraneural Intra neural Intra fascicular Neural axonal Neural schwann cell (myelin) Blood vessels Fat

http://trigeminalnerve.org.uk/

Risks factors for Dental LA NIs • Block anaesthesia √ • Lingual nerve > IAN √

• Technique or Anatomy?

• Concentration of LA agent √ • Agent toxicity √ • Speed of injection √ • Multiple injections √ • Severe pain on injection √ • Type of LA Agent √

• Type of vasoconstrictor? • Sedated / anaesthetised patients? • Lack of LA aspiration?

• Volume of LA • Patient?

Bupivacaine

Mepivacaine

Citanest

Lidocaine

Articaine

Cause chemical -Agent toxicity

Methaemoglobinaemia is associated with large doses of Prilocaine

http://trigeminalnerve.org.uk/

Risk Factors LA concentration Increased concentration of LA agent DOES increase risk of nerve injury!

– Hillerup & Jenson 2008

– Haas &Lennon 2009

– Garisto et al 2010

– Hillerup 2010

– Renton 2011

– Haas 2011 • Articaine 21 times more likely to cause injury

– Hillerup et al 2011

– Hillerup et al 2011b • Rat nerve neurotoxicity 2vs 4% Articaine =concentration of Agent more likely neurotoxin than mechanical injury with saline

– Pogrel 2012

– Jacobs K report IFDAS 2015

– Piccini et al 2015

– Gaffen & Haas 2009

http://trigeminalnerve.org.uk/

From Pogrel 2012

There is no proven increased efficacy of

Articaine 4% VS Lidocaine 2 % IDBs

• Claffey E, Reader A, Nusstein J, Beck M, Weaver J. Anesthetic efficacy of articaine for inferior alveolar nerve blocks in patients with irreversible pulpitis. J Endod. 2004 Aug;30(8):568-71.

• Sierra Rebolledo A, Delgado Molina E, Berini Aytís L, Gay Escoda C Comparative study of the anesthetic efficacy of 4% articaine versus 2% lidocaine in inferior alveolar nerve block during surgical extraction of impacted lower third molars. Med Oral Patol Oral Cir Bucal. 2007 Mar 1;12(2):E139-44.

• Mikesell P,Nusstein, Reader A,Beck M,WeaverJ. A Comparison of Articaine and Lidocaine for Inferior Alveolar Nerve Blocks. J EndodonticsVolume 31, Number 4, April 2005

• Isabel Peixoto Tortamano, DDS, MSc, PhD, Marcelo Siviero, DDS, MSc, Carina Gisele Costa, DDS, MSc, PhD, Inês Aparecida Buscariolo, DDS, MSc, PhD, and Paschoal Laércio Armonia. A Comparison of the Anesthetic Efficacy of Articaine and Lidocaine in Patients with Irreversible Pulpitis. J Endodontics Volume 35, Number 2, February 2009

http://trigeminalnerve.org.uk/

Articaine (4%) no more clinically effective than 2% Lidocaine for pulpitic molars but very effective as buccal supplementary buccal infiltration

PAIN on injection? • 60% more likely to experience persistent neuropathy

• Review your pt next day

• Reassure 75% are temporary

• Early Medical intervention required?

Smith and Lung 2006

OUCH!

Risk Factors LANI Pain on injection

Other Risk factors for LA NIs – Sedated or anaesthetized patients? There is no evidence to support unresponsive patients, are less likely to protect themselves when neuralgia (funny bone reaction) occurs as the IDB needle encroaches too close to the nerve.

– Lack of LA aspiration? Again there is no evidence to support that aspiration during IDB results in lower persistent neuropathies but a pragmatic view may infer less chemical injected intra neural will cause less chemical nerve injury.

– Haemorrhage The iron content of haemoglobin is very irritant to neural tissue • Primary or secondary haemorrhage may result in scarring either epi or intra neural causing further

ischaemic and damage to the nerve

– Infection related neuropathy We frequently see infection related neuropathy associated with non vital teeth with apices close to the Inferior dental canal. Infection related to IDBs is rare and likely to be related to haematoma formation which is also very rare.

http://trigeminalnerve.org.uk/

Ultimately most cases of paresthesia resolve within eight weeks (Malamed 1997).

Ultimately most cases of paresthesia resolve within eight weeks (Malamed 1997) 25% of IDB injuries are permanent!!

LA nerve injuries related to IDB 25% persistent No treatment we just have to sit and wait for recovery No evidence that Vit B complex, NSAIDs or steroids improve outcome Patients are baffled as to why they are not warned about the possibility of nerve injury

Consent- Incidence LA Nerve Injury (IANB) • Previous estimate -Inferior alveolar nerve block resulted in permanent paresthesia with

an incidence rate of between 1:26,762 and 1:160,571 (Pogrel et al., 2000).

• Sambrook & Goss 2011 reported prolonged anaesthesia in 15 cases in one year in South Australia (8% of Australian population) extrapolation leads to an estimated incidence of 1 in 27.415 cases of prolonged neuropathy related to LA Inferior dental blocks per year in Australia.

• Haas and Lennon 2000 found the incidence of local anesthetic induced paresthesia to be 1 in 785,000 injections

• Garisto et al 2010 reported a rate of 1 in 13,800.970.

• Renton et al 2013 reported a much higher incidence based upon surveys of dentists and a specialist per injections

– GDP restorative procedures 1 in 14K temp and perm 25% permanent

– Oral surgery 1 in 3.3K 75% recover 25% permanent

– Equivalent to 1 in 52K permanent injury

http://trigeminalnerve.org.uk/

Recommended in USA 1939

Obtaining written informed consent for the administration of local anesthetic in

dentistry.

Daniel L Orr, William J Curtis

Oral and Maxillofacial Surgery, Anesthesiology for Dentistry, University of Nevada School

of Medicine, Las Vegas 89102-2287, USA.

Journal of the American Dental Association (1939) (Impact Factor: 1.82). 12/2005;

136(11):1568-71.

ABSTRACT The purpose of this study was to examine the frequency with which dentists

obtain written informed consent for the administration of local anesthetic in dentistry.

The authors administered an informal survey to 252 dentists.

http://trigeminalnerve.org.uk/

Consent – Nerve injury warnings related to IANBs Routine in Germany

What do anaesthetist routinely warn their patients

undergoing spinal Block LA nerve injury incidence?

Compare this dental LANI rate with anaesthetic spinal block procedures.

NAP3 reports the estimated that nerve injury resulting from neuroaxial blocks

(epidurals, spinals and combined epidural with spinals) resulted in

sensory +/or motor nerve injury in 1 in 24-54K patients

(and paraplegia or death in 1 in 50-140K patients!)

ALL PATIENTS ARE WARNED! National RCA Audit 2012

IANB related Permanent dental nerve injury rate 1:26-52K

Why do we not routinely warn our dental patients?

As is done in Germany http://trigeminalnerve.org.uk/

Prevent Local anaesthesia induced nerve injuries by;

• Avoid multiple blocks

• No IDBs under GA

• Avoid high concentration IDBs (Articaine,Mepivacaine,Prilocaine)

• Stick to Lidocaine ID blocks for now!

• Is the future infiltration only with no IAN blocks????????

Renton T, Adey-Viscuso D, Meechan JG, Yilmaz Z. Trigeminal nerve injuries in relation to the local anaesthesia in mandibular injections. Br Dent J. 2010 Nov;209(9):E15

Infiltration Local Anaesthesia

• An update on pain • The patients perspective • Systemic issues for LA • Complications of LA • Failed LA • Avoiding LA nerve injuries • Update on LA techniques

Kings College London-Tara Renton

Outline

Changing LA practice

Kings College London-Tara Renton

Know your anatomy!

Kings College London-Tara Renton

Spot the lingual nerve!

IANB techniques • Should we always reach for the IANB?

Kings College London-Tara Renton

Direct Halstead technique Is the lingual nerve at risk?

Kings College London-Tara Renton

Should we use the indirect Halstead IANB method?

Or can alternative techniques reduce nerve injury? When is Gow Gates indicated?

Kings College London-Tara Renton

Or Akinosi?

http://vimeo.com/6508891

The Akinosi vs Gow gates

• Patient ‘impossible’ to anaesthetise

– Articaine infiltrations buccally

– Lidocaine block

– Mepivacaine Akinosi

• And WAIT>>>>>>>>>>>!

LA Failure

What about infiltration techniques?

Kings College London-Tara Renton

Infiltration technique

No palatal blocks required!

• Anesth Prog. 2013 Summer;60(2):42-5. doi: 10.2344/0003-3006-60.2.42. Comparison of buccal infiltration of 4% articaine with 1 : 100,000 and 1 : 200,000 epinephrine for extraction of maxillary third molars with pericoronitis: a pilot study.

• Lima JL Jr Dias-Ribeiro E Ferreira-Rocha J Soares R Costa FW Fan S Sant'ana E Prospective, double-blind, controlled clinical trial involved 30 patients between the ages of 15 and 46 years who desired extraction of a partially impacted upper third molar with pericoronitis

Local anaesthesia

With respect to maxillary infiltration anesthesia, some studies have found 4% articaine to be more effective than 2% lidocaine for lateral incisors but not molars (Evans et al., 2008), while others reported no clinical superiority for this injection (Oliveira et al., 2004; Vähätalo et al., 1993). A recent randomized controlled trial found a statistically significant difference supporting use of 4% articaine in place of 2% lidocaine for buccal infiltration in patients experiencing irreversible pulpitis in maxillary posterior teeth (Srinivasan et al., 2009)

Smart LA •Articaine 4% Buccal Infiltration

• +/- IDB Lidocaine 2%

•Articaine 4% Buccal Infiltration

•Post + ant near Mental foramen

• +/- Lingual Inf Lidocaine 2%

•Buccal infiltration + Lingual both Lidocaine 2%

136

Meechan JG The use of the mandibular infiltration anesthetic

technique in adults. J Am Dent Assoc. 2011 Sep;142 Suppl

3:19S-24S.

Local anaesthesia

Can Articaine 4% infiltration replace Lidocaine 2% IANBs for routine

dentistry?

Kings College London-Tara Renton

BACKGROUND: Articaine administered through buccal infiltration (BI) has been suggested as providing adequate posterior mandibular analgesia. This study compared the efficacy of articaine 4% with 1:100 000 adrenaline (test) and lignocaine 2% with 1:80 000 adrenaline (control), delivered either through an inferior alveolar nerve block (IANB) or BI for routine restorative procedures in mandibular posterior teeth among children. RESULTS: Fifty-seven children were recruited into the study; 29 allocated to IANB. Analgesia success for IANB 100%; BI 67%; p < 0.001. Analgesia success for BI with articaine 71%; lignocaine 64%, p > 0.05. Analgesia success was associated with fewer reports of painful dental treatment, p = 0.005. CONCLUSIONS: There was higher success and less painful treatment with IANB. There was no statistically significant difference in local analgesia success between articaine and lignocaine when delivered via BI.

A comparison of articaine 4% and lignocaine 2% in block and infiltration analgesia in children. Arrow P. Aust Dent J. 2012 Sep;57(3):325-33. doi: 10.1111/j.1834-7819.2012.01699.x. Epub 2012 May 28

For paedodontic restorative

For pulpitis adult molars

• Articaine infiltration superior to LA IDB

Successful extractions in

Incisors-premolars 90%

M1Ms 60%

M2Ms 75%

Prospective audit 280 extractions by dental UGs

-no palatal blocks given

- Articaine infiltration

- Lidocaine IDB rescue

87% success!

For adult extractions

• Reduce nerve injury risk during implant bed

preparation by using infiltrative anaesthesia

Supraperiosteal infiltration anesthesia safe

enough to prevent inferior alveolar nerve during

posterior mandibular implant surgery?

Etoz OA, Er N, Demirbas AE.Med Oral Patol

Oral Cir Bucal. 2011 May 1;16(3):e386-9

Implant surgery

• Lidocaine 2% infiltration equally effective as Articaine 4% infiltration n Maxilla

• Articaine 4% infiltration 3.4 x more effective than 2% lidocaine infiltration for mandibular dentistry

Kings College London-Tara Renton

Intraligamentary and intra-osseous anaesthesia

pulp

dentine

intra-osseous injection

intraligamentary injection

alveolus

gingiva

Modified LA techniques

Injection in the periodontal ligament

between tooth and alveolar bone

• Needle inserted in a 30-40 ° angle to

the longitudinal axis of the tooth up to

the point of greatest resistance.

• A small volume (about 0,2 ml) of the

local anesthetic is slowly injected

under pressure

• Procedural Success rate: 80-100%

Techniques – Intraligamentary anesthesia

Shabazfar N., Daubländer M., Al-Nawas B., Kämmerer P.W.: Periodontal intraligament injection as alternative to inferior alveolar

nerve block - meta-analysis of the literature from 1979 to 2012. Clin Oral Investig (2014)

versus inferior alveolar nerve block?

Shabazfar N., Daubländer M., Al-Nawas B., Kämmerer P.W.: Periodontal intraligament injection as alternative to inferior alveolar

nerve block - meta-analysis of the literature from 1979 to 2012. Clin Oral Investig 2014.18(2):351-358.

Cardiovascular parameters PDL < IANB

Injection pain PDL < IANB

Second injection needed PDL ≈ IANB

IANB latency > 3 min; PDL instantly

IANB longer compared to PDL

Techniques – Intraligamentary anesthesia

versus inferior alveolar nerve block?

BUT

PDL with

• destruction periodontal fibers

• risk of bacteriaemia

Kämmerer P.W., Palarie V., Schiegnitz E., Ziebart T., Al-Nawas B., Daubländer M.: Clinical and histological comparison of pulp

anesthesia and local diffusion after periodontal ligament injection and intrapapillary infiltration anaesthesia. J Pain Relief.

2012; 1:108. doi:10.4172/2167- 0846.1000108- 0846.1000108

Techniques – Intraligamentary anesthesia

Intraligamentary anesthesia for extractions?

158 patients with 245 teeth

Manual intraligamentary syringe n=105

Inferior alveolar block n=140

Techniques – Intraligamentary anesthesia

Intraligamentary anesthesia for mandibular extractions?

YES

- Less local anesthetic

- Faster onset

- Faster start of treatment and

faster end of treatment

- No intravasal injections

- Shorter soft tissue anesthesia

Techniques – Intraligamentary anesthesia

• Computerised infiltration and intra-ligamentary techniques

Kings College London-Tara Renton

Modified local techniques- AMSA

• Techniques include: • AMSA Ant sup middle alveolar nerve (incisal block) canine to canine

always with gingival margin and premaxillary palatal mucosa very slow rate requires topical anaesthetic.

• Infiltration palatal block don’t get numb lip with only one cartridge providing anaesthesia in half first molar to incisor and gingival margins (Williams 1999)

• PASA-nasoplataine block into foramen (Petxer 2001) • Figure 6.9 Figures of techniques • •

2006, the manufacturers of the original CCLAD, the Wand, introduced a new device, Single Tooth Anesthesia (STA™). STA incorporates dynamic pressure-sensing (DPS) technology that provides a constant monitoring of the exit pressure of the local anesthetic solution in real time during all phases of the drug's administration (Hochmann 2001).

Originally designed for use in medicine in epidural regional anesthesia (Ghelber ey al 2005), STA utilizes an adaptation of DPS to dentistry as a means of overcoming the problems associated with PDL injection (Hochmann 2007), and simplifies AMSA and P-ASA injections.

Modified local techniques- STA

dental cartridge

computerised delivery

control unit

connecting tubing

needle on holder ? possible due to computerised injection

systems

palatal anterior superior alveolar nerve

block

anterior middle superior alveolar nerve

block

Modified local techniques- Wand

The Comfort control (CC) Dentsply system (2001)

• Although, use of the Comfort Control Syringe may be more perceptive than that of the CompuDent system in the sense that the injection is controlled by hand, the syringe is bulky and more cumbersome to use than the Wand handpiece (Clark & Yagiela 2010).

• A comparison between the traditional dental syringe and the Comfort Control Syringe revealed no meaningful differences in ease of administration, injection pain and efficacy, and acceptance by patients(Grace et al 2003).

Kings College London-Tara Renton

Modified local techniques-Comfort control (CC) Dentsply system (2001)

Jet injector In 1947 Figge and Scherer Jet injection is based on the principle that liquids forced through very small openings, called jets, at very high pressure, can penetrate intact skin or mucous membrane. The primary use to obtain topical anaesthesia before the insertion of a needle. The jet injector is not an adequate substitute for the more traditional needle and syringe in obtaining pulpal or regional block anaesthesia. Three controlled studies of needleless devices have been reported. In an experiment, the needleless method (INJEX) seemed to provide faster anesthetic results, though the difference was not significant(Saleh et al). The participants were described as “volunteers,” which implies that they were adults. In the second controlled study, 94 patients aged 2 to 16 years who required 2 similar treatments on either side of the mouth received a traditional injection on one side and the needleless injection (Hypospray) on the other side during the same visit. Eighty-one percent of the children stated that they preferred the needleless technique. When the children were dichotomized by age, there was no relationship between age and method preference. The children’s level of cooperation was also not related to preference. About 5% of the children experienced pain with the needleless injection, while about 1% found the traditional injection painful. Gender effects were not reported (Schmidt et al).

Modified local techniques- Jet injector (needleless syringe - "Injex")

Remember

Intraosseous LA = intravenous LA!

Modified local techniques-Intraosseus

Future trends • The future interest is the possibility of development of newer improved agents

(sensory blocking agents only) and devices and techniques for achieving profound sensory anesthesia. A nasal spray (http://clinicaltrials.gov/ct2/show/NCT01302483 ) has shown to anesthetize maxillary anterior six teeth is set to be tested in an FDA Phase 3 trial, which will assess the spray's effectiveness compared to the current “gold standard” treatment - painful anesthesia injections.

• Another development is a syringe micro vibrator (SMV), (Shahidi Bonjar AH. Syringe micro vibrator (SMV) a new device being introduced in dentistry to alleviate pain and anxiety of intraoral injections, and a comparative study with a similar device. Ann Surg Innov Res. 2011;5:1–5. ) a new device being introduced in dentistry to alleviate pain and anxiety of intraoral injections.

• Adjunctive medication

• MISTS………

Kings College London-Tara Renton

• Preoperative NSAIDs improving LA pulpal anaesthesia

• Nasal ‘Mist’ as effective as maxillary infiltrations for adult pulpal anaesthesia

Be smart Avoid complications

Recommendations Prevention LA Nerve injuries

Prevention of LA nerve injuries is possible and some simple steps may minimise LA related nerve injuries:

• TAILORED INFILTRATION LA

• Avoid IAN blocks by using infiltrations supra periosteal or intraligamental injections for extractions Infiltration dentistry

• Avoid high concentration LA for ID blocks (use 2% Lidocaine as standard). There is increasing evidence that higher concentration agents are more neurotoxic thus more likely to cause persistent inferior dental block (IDB) related neuropathy.

• Avoid multiple blocks where possible

• Modify training NOT to HIT the nerve! -Should we aspirate and avoid direct IDB or use higher IDB techniques?

• Change of practise is always a challenge and we must start with training our dental students in procedure specific LA techniques and consenting patients appropriately in the light of the associated risks.

http://trigeminalnerve.org.uk/

Recommendations prevent LANIs Should LA cosent practice change?

• Consent for LA Patents are routinely warned of a risk of nerve injury when routinely undergoing epidural or spinal injections (17) Reports the estimated that nerve injury resulting from neuroaxial blocks (epidurals, spinals and combined epidural with spinals) resulted in sensory or motor nerve injury in 1 in 24-54K patients (and paraplegia or death in 1 in 50-140K patients)). Already in Germany most of Europe and US patients are routinely warned about risks associated with IDBs (46).

www.trigeminalnerve.org.uk

Don’t just reach for the IANB use your imagination!

For perio, paedo and routine dental extractions

Articaine buccal infiltration only OR Intraligamental technique

For Hot Pulps

IANB Lidocaine 2% plus Articaine 4% Buccal infiltration

For Third molar surgery

Articaine buccal infiltrations 2ml 4% and IDB with lidocaine 2%

when needed (NO palatals required!) OR Intraligamental technique

For Implants Articaine buccal infiltration ONLY

Recommendations

Thank you

Kings College London-Tara Renton

Kings College London-Tara Renton

Launch December 2nd 2016 Orofacialpain.org.uk Orofacial pain Masters programme starts at KCL Oct 2017