Local Anaesthetic* Flashcards

1
Q

Topical Anaesthetics - chemical needs for function? absorption rate? effective where (depth)? types of TopLA? Other LA not suitable for topical? benzocaine adverse reaction? other formulations and application? Advantages and disadvantages to topical?

A

Chem:
- higher conc needed to diffuse through mucous mem
Absorption:
- no vasoconstrictor therefore rapid vasc absorption (IV only)
Effective:
- surface tissue 2-3mm
Types:
- lidocaine and benzocaine (other types such as articaine and mepivacaine conc to anaesthetise potential overdose or tox)
Benzocaine:
- ester based allergic reaction at site of application
Other:
- spray or gel (xylocaine)
- sterility problems
- gel applied for 2-3 mins via cotton bud
Adv:
- desensitisation to localised area
- ease of needle penetration for infiltration
Dis:
- absorption rate equal to IV, and so should be used sparingly

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2
Q

Topical - pastes/solutions indications for use? application for use?

A
Indications:
- analgesic prior to injection
Application:
- according to consistency
- sol via cotton wool
- paste applied to dried area
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3
Q

Topical - drugs for use? enzymatic addition? factors for onset and depth of analgesic?

A

Drugs:
- benzocaine, amethocaine and lignocaine (2 or more combined)
Enzyme:
- hyaluronidase allows access of the analgesic to the tissues
- by dissolving cell junctions
Factors:
- permeability of the tissue related to degree of keratinisation

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4
Q

Topical - Oraqix - combination? concentration? appearance? same as? eutectic definition? indications? cartridge size? onset and duration? max dose? using Oraqix? Advantages of oraqix?

A
Combo:
- lidocaine and prilocaine
Conc:
- 2.5% lido and 2.5% prilo
Appearance:
- clear liquid
Similar to:
- EMLA 
Eutectic:
- liquid which sets as a gel at body temp
Indications:
- non-injectable dental LA periodontal pockets
- for probing, scaling or RSI
Cartridge:
- 1.7g
Onset and duration
- 30s set and 20m duration
Max:
- 5 cartridges
Using:
- must be liquid, cool if in gel form
- air bubble is no problem
Adv:
- no injection (phobia)
- no lingering numbness
- quick onset
- constant numbing
- gel state for stability
- anaesthesia confined to desired area
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5
Q

Definitions of local infiltration? field block? nerve block?

A

Local infiltration:
- small terminal nerve endings are anaesthetised with LA
Field block: (infiltration)
- LA deposited near larger terminal nerve branches (apex for pulpal anaesthesia)
Nerve block:
- LA deposited close to main nerve trunk

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6
Q

Infiltration technique (supraperiosteal injection) - indication?

A

Indication:

  • pulpal anaesthesia in all max upper teeth
  • multiple teeth require multiple injections
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7
Q

Before administration Infiltration - what to think about? armamentarium (tools)?

A
What:
- hope to achieve?
- best technique?
- medical history?
- consent?
Armamentarium:
- appropriate anaesthetic sol
- syringe system
- short needle 27-30 gauge
- sharps
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8
Q

Technique for administration - patient position? emergencies? tissues? target? useful landmarks? needle orientation? needle insertion? LA deposition?

A
Patient:
- semi recumbent or fully back
Emergencies:
- over 50% of emergencies occur after LA admin (due to vaso-vagal syncope)
Tissues:
- pull them taut
Target:
- apex of tooth to be anaesthetised
Useful:
- mucobuccal fold
- crown of tooth
- root contour
Orientation:
- bevel faces bone
Insertion:
- into height of mucobuccal fold over target tooth at 45 deg
- advance until bevel above the apex
- stabilise with finger stop
- don't advance until bone is hit
- don't inject into frenum
Deposition:
- deposit a few drops
- aspirate
- continue if -ve 1/2 cart over 30s (no tissue ballooning)
- wait 3-5mins to kick in
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9
Q

Anaesthesia of the maxilla - why infiltration works?

A

Why:

- as the outer bone covering the maxillary teeth is thin

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10
Q

Anaesthesia of maxillary incisors and canines - innervation of teeth? buccal gingiva and palatal gingiva? injection area?

A
Teeth and buccal gingiva:
- sup alveolar nerve (ant)
Palatal gingiva:
- nasopalatine
Area:
- given near or into the buccal fold near bone towards apex of tooth
- target and adj teeth
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11
Q

Maxillary premolar anaesthesia - innervation? injection area (2 areas)?

A

Innervation:
- by the superior plexus (mostly middle sup alveolar nerve and some of the post sup alveolar nerve)
Area:
- at the apex of the target tooth buccally
- palatally injection near the target tooth (anaesthesia of the greater palatine and nasopalatine)

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12
Q

Maxillary Molar anaesthesia - difficulty why? solution? innervation - of teeth? buccal gingiva? periosteum? pulp?

A

Difficulty:
- achieving close proximity with the root apices
- zygomatic arch arises from maxilla can be obstructive
Solution:
- 2 infiltrations mesially and distally to the first molar
Innervation:
- by the post sup alveolar to the teeth, buccal gingiva and periosteum
- greater palatine for pulp

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13
Q

Palatal anaesthesia - direct approach - molar nerve target? caution for? never do this? injection site? success sign? avoid landmarks? indications? tip?

A
Target:
- greater palatine nerve 
Caution:
- avoid injecting directly around greater palatine foramen
Never:
- inject post to vibrating line (lesser palatine supplies soft palate
Site:
- equidistant point between median raphe and gingival margin of target tooth
Success:
- blanching of tissue
Avoid:
- rugae and foramen
Indications:
- after buccal infiltration
Tip:
- apply Pa to injection site prior to injection
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14
Q

Palatal anaesthesia - indirect approach - access via? needs initially? injection technique?

A
Access:
- via the buccal papilla
Needs:
- buccal infiltration first
Technique:
- short needle introduced perpendicular to the surface of the papillae and advanced before the needle pierces the palatal mucosa
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15
Q

Anaesthesia of mandible - infiltration - limited why? solution? new drug advancements?

A

Why:
- incisors have thin bone covering
- premolars and molars are covered by thick compact lamina preventing diffusion
Solution:
- inferior alveolar block
Advancements:
- 4% articaine with 1:100,000 ADR used at first molar

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16
Q

Anaesthesia of mandibular incisors and canines - innervated by? midline? technique?

A
Innervated:
- incisive nerve
- lies within the ID canal 
Midline:
- anastomosis 
Technique:
- tip of needle angled to apex
- canine may need mental block
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17
Q

Anaesthesia of lingual nerve - 2 techniques?

A

Techniques:

  • infiltration just under the attached gingiva lingually
  • interpapillary injection (into interdental papilla, insert into centre near crest bone, blanching confirms success used following infiltration)
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18
Q

Anaesthesia of mandibular buccal gingiva of post - infiltration - indications?

A

Indications:

  • LR/LL8s and its surrounding gingiva
  • post teeth
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19
Q

Anaesthesia onset - time? factors? duration?

A
TIme:
- within 2m
Factors:
- anaesthetic type
- vasoconstrictor
Duration:
- 1hr pulpal
- tissue longer
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20
Q

Nerve block definition?

A

Placement of LA sol around the main trunk of a sensory nerve or one of its major branches blocking all sensory input from the whole region of tissues supplied by that nerve

21
Q

inferior alveolar nerve block - course? injection site?

A

Passage:
- inferior alveolar nerve passes down between lateral and medial pterygoid muscle
- behind the lingual nerve and through the mandibular foramen into the mandibular canal
- nerve runs forward in the canal and gives of ranches to the teeth of the mandible
Injection site:
- at the mandibular foramen found on the medial aspect of the ramus before the nerve enters
- very close to lingual nerve
- achieved by introducing LA into the lateral side of mouth in the fat of the pterygomandibular space

22
Q

Before administration IDB - what to think about? armamentarium (tools)?

A
What:
- hope to achieve?
- best technique?
- medical history?
- consent?
Armamentarium:
- appropriate anaesthetic sol
- syringe system
- long needle 27 gauge
- sharps
23
Q

IDB - direct technique - aim? landmarks? technique (palpate)? entry of needle (location)?

A

Aim:
- deposit LA close to mandibular foramen
Landmarks:
- external oblique ridge at anterior aspect of ascending ramus
- pterygomandibular raphe (separates the buccinator from the sup constrictor)
- runs from pterygoid hamulus down to mandible in retromolar region
- a V ridge of mucous mem
Technique:
- using thumb palpate the ramus whilst the injection is given
Entry:
- from premolars of opposite side
- barrel of syringe is parallel to lower occlusal plane
- needle neter tissue back of mouth
- lateral to pterygomandibular raphe
- medial to ramus of mandible
- at a level halfway up the thumb palpating the ramus
- advance needle until bone is felt and then withdraw slightly
- aspirate
- then deposit 2ml

24
Q

Electric shock phenomenon - what occurs? why? solution? help the patient? diagnostic sign of success? reasons for failure of IDB?

A
What occurs:
- jump from sharp pain
Why:
- Pa on nerve bundle or hit the lingual nerve 
Solution:
- withdraw slightly
Help:
- reassure and document
Sign:
- tingling of lower lip
Failure: try articaine
- anatomical variation
- little solution
- give it time
- wrong placement
- additional nerve supply
25
Q

Alternative mandibular block techniques if IDB fails - Gow-Gates? Vazirani-Akinosi?

A
Gow-Gates:
- all sensory nerves v3
- extra-oral landmarks
Vazirani-Akinosi
- closed mouth technique
- good for trismus
- no bone contact
- hard to visualise path
26
Q

Incisive and mental nerve blocks - technique? indications?

A

Technique:
- depositing LA at mental foramen (between apices of 1st and 2nd premolar)
- sol enters foramen to block incisive nerve to premolar and ant mand teeth and soft tissues
Indications:
- multiple ant teeth

27
Q

LA - maxillary division - branches of interest?

A

Branches:

  • superior alveolar (posterior, middle and anterior)
  • nasopalatine
  • greater palatine
28
Q

Anterior superior alveolar nerve - supplies? anastomoses with?

A

Supplies:
- 1 to 3 anterior teeth
Anastomoses with:
- branch from the adj side (cross-over)

29
Q

Middle superior alveolar nerve - supplies? presence?

A

Supplies:
- hard and buccal soft tissue of mesiobuccal 6, 5 and 4
Presence:
- not always present (anastomose with post)

30
Q

Posterior superior alveolar nerve - supplies? anastomose? if middle is present?

A

Supplies:
- hard and buccal soft tissue of 8, 7 and 6
Anastomose:
- with middle superior alveolar
Middle:
- post will innervate MB 6 to first premolar/canine

31
Q

Palatal nerves - examples and supplies?

A

Nasopalatine - supplies the palatine tissue of the premaxilla
Greater palatine - supplies palatine tissue from the last molar to the first premolar/canine

32
Q

LA - Mandibular division - branches of interest?

A

Branches:

  • inferior alveolar
  • incisive
  • mental
  • long buccal
  • lingual
33
Q

LA - mandibular division - anterior division branches?

A

Branches:

  • masseteric
  • deep temporal (ant/post)
  • buccal nerve (soft tissue of lower 8-6/5)
  • lateral pterygoid
34
Q

LA - mandibular division - posterior division branches (auriculotemporal? lingual? mylohyoid? inferior alveolar? incisive? mental?) supply what?

A

Branches:

  • auriculotemporal
  • lingual (lingual gingiva and tongue)
  • mylohyoid
  • inferior alveolar (hard and soft tissue of lower teeth bar buccal of 8-6)
  • incisive (extension of IAN and supplies incisive teeth)
  • mental (extension of IAN exits canal at apices of premolar teeth and supplies soft tissue only lower lip and chin)
35
Q

Key landmarks for injection sites?

A
Pterygomandibular raphe
Coronoid notch
Incisive papilla
Hamular notch
Buccal and labial frenum
36
Q

Cartridges of LA solution - size? storage? damage? expiry? patient record LA notes?

A
Size:
- 2.2 or 1.8ml
Storage:
- room temp
Damage:
- discard if not sound
Expiry:
- within use by date
Records:
- anaesthetic used and strength
- vasoconstrictor and strength
- site deposited
- amount deposited
- batch number and expiry date
37
Q

Needle - anatomy? needle points (contact with? damage causes?) bevel definition? septodont bevel (innovation)? purpose of bevel? bevel identification (sign? technique? advantage?

A

Anatomy?
- bevel (tip)
- shaft (between tip and hub)
- hub (start)
- syringe adapter
- cartridge penetration end
Needle points:
- needle must contact bone before deposition
- needle can become damaged (fishhook style and cause pain on withdrawal)
Bevel:
- is the slanted surface of a needle, which creates the tip and facilitates nontraumatic entry into tissues
- septo scalpel designed bevel
- allow smoother penetration, less tissue displacement, deflection and force
Identification:
- bevel towards the bone (black mark on the syringe adapter)
- reduces trauma and increases comfort

38
Q

Needle - gauge definition? sizes? gauges used and why? length - sizes and indications?

A
Gauge:
- diameter of the lumen
Sizes:
- 23, 25, 27 and 30
Gauge used:
-  25 and 27
- less deflection
- greater accuracy
- less breakage 
- better aspiration
Sizes and indications:
- long 30-35mm for all techniques with significant penetration of soft tissue (IDB)
- short 20-25mm all other techniques
- ultrashort PDL
39
Q

Syringes - aspirating? self-aspirating? pressure? jet injector? safety? computer-controlled?

A

Pa PDL inj

Jet injector is needleless

40
Q

Aspiration - why we do this? technique? self-aspiration? active aspiration (bung? piercing? technique? dis?)?

A

Why:
- deposition into a vessel can cause systemic disturbances
- check to see if we’ve injected into the correct place
Technique:
- insert needle
- aspirate by pulling plunger back, check cartridge for blood, of so reposition and try again
Self-aspiration:
- no active movement required
- adapted bungs
Active aspiration:
- standard solid bung
- cartridge pierced by barb on plunger
- manually pull back on plunger creating
- dis; needle movement and small hand problems

41
Q

Safety plus - use? needle holster? legislations? aspiration? Handles and bungs? Le eject system?

A
Use:
- prevent needle stick injuries
Needle holster:
- plastic cover over the needle before and after use (clicks when in place)
Legislations:
- Safer sharps 2013
Aspiration:
- allows both techniques
Handles:
- rubber bung needs to be removed before decon
Le eject:
- needle pings off
42
Q

Types of needlestick injuries?

A

Percutaneous injury

Mucocutaneous injury

43
Q

Percutaneous injury - definition? transmission?

A

Definition:
- needle or other sharp instrument accidentally penetrates the skin
Transmission:
- contaminated with blood or other bodily fluid, potential risk of transmission
- occupational exposure

44
Q

Mucocutaneous injury - definition? transmission?

A

Definition:
- blood or other body fluid splash into eyes, nose, mouth or broken skin
Transmission:
- risk is lower

45
Q

Protocol for a occupational exposure?

A

Protocol:

  • immediately wash and clean affected area
  • assess significance
  • if not from patient arrange OH appointment within 36 hours
  • identify source patient
  • if not identified take blood sample for storage (poss HepB prophylaxis)
  • source patient identified ask patient for blood sample with consent (if not HIV +ve, start HepB prophylaxis)
  • source patient HIV status
  • if yes, call OH and start prophylactic therapy
46
Q

Management of needlestick injury - first aid treatment? HIV treatment - drug names

A

Wash wound thoroughly (no scrub)
Free bleeding should be encouraged (no sucking)
HIV exposure - PEPs (continued Truvada and Kaletra for 28 days)

47
Q

Staff at risk?

A
Dentist
Nurse
LDU
Cleaning 
Waste disposal
Patients
48
Q

Factors that increase risk and incidence of needlestick?

A
Percutaneous worse than mucocutaneous
Blood from vein or artery
Fresh blood over dried blood or other body fluid
Hollow bore > solid bore
Wider gauge
Deeper injury
Visible blood
No PPE
Poor first aid measures
Patient having a known transmissible disease