Local Anaesthetics Flashcards
What is the most common use of local anaesthetic?
- Operative pain control
- Minimal caries removal may not require LA (slow speed)
- All other cavity preparations require LA
Name 2 uses of LA, other than operative pain control
- Diagnostic tooth
2. Control of haemorrhage
Name 3 forms of surface anaesthetics available
- Spray
- Gel
- Solution
Name 2 commonly used surface anaesthetic gels
- 20% benzocaine
2. 5% lidocaine analgesic
What is the most commonly used surface anaesthetic spray?
10% lidocaine
Name 2 topical anaesthetics for skin (not recommended intraorally)
- EMLA (Lidocaine 2.5% and Prilocaine 2.5%)
2. Ametop
Name 6 convention LA (amide) solutions used
- Lidocaine Hydrochloride (2%) with adrenaline (1:80,000)
- Plain Lidocaine
- Prilocaine (3%)
- Mepivicaine Hydrochloride (3%) with no adrenaline
- Articaine (4%) with adrenaline (1:100,000)
- Bupivicaine (0.25%) with adrenaline (1:200,000)
What is the gold standard UK solution of choice for conventional LA?
Lidocaine Hydrochloride (2%) with adrenaline (1:80,000)
Compare articaine to lidocaine
- Fast onset
- Profound anaesthetic so less LA used
- Less preservatives
Name 2 commonly used LA techniques in children
- Infiltration
2. Regional block
What is an infiltration anaeshtetic?
Extravascular placement of LA in region to be anaesthetized
What is the aim of infiltration?
- Deposit LA near to apex, supra-periosteal
- 0.5-1.0ml sufficient for pulpal anaesthesia
- Buccal approach closer to apex
What is the LA technique of choice in the maxilla?
Infiltrations
Describe infiltration use in the mandible
- Buccal infiltration adequate for primary molars
- Unreliable for permanent molars
- Block may be better
Describe the technique of an inferior alveolar block
- Direct approach from primary molars opposite side
- Syringe parallel to occlusal plane
- Insertion approx 5mm above occlusal plane
- If contact bone immediately, don’t withdraw
- Short needle may be used in yougn child
Describe how to carry out a lingual block
Withdraw half way following IDB, aspirate and deposit remaining solution
Describe a mental block
- Readily given as mental foramen faces anteriorly
- Needle advanced in buccal sulcus between 1st and 2nd molar apices
- Excellent soft tissue anaesthesia
- Problem for incisors due to cross over supply
Describe an intraligamentary anaesthesia
- Intraosseous injection with LA entering via PDL
- Recommended dose is 0.2ml/root
Name 2 needle free devices
- Jet injectors
2. Injex systems
Name 3 advantages of needle free devices
- Mucosa anaesthetised to depth of 1cm without use of needle
- Deliver jet under high pressure
- Conventional LA solution used
Name 4 advantages of injex systems
- Expensive
- Technique not applicable to all areas
- Soft tissue damage if careless techniques
- Loud noise and bad taste following delivery
Name 3 advantages of intraligamentary anaesthesia
- Less uncomfortable than IDB or palatal
- Rapid onset and less effect on soft tissue
- Use in patients where IDB is containdicated
Name a time when IDB is contra indicated
Bleeding disorders
Name 2 disadvantages of intraligametary anaesthesia
- Immature root or short root has risk of avulsion
2. Risk of damage to permanent successor
Name 4 contributing factors to the clinical decision on whether to administer LA to a child
- Age of child and cooperation
- Urgency and type of treatment
- Parental input
- Maxillary infiltration as first experience if possible
Describe 4 points of organisation of equipment and materials of administration of LA
- Sharp fine needle
- Aspirating syringe
- Allow LA to reach room temperature
- Keep out of side
Describe a good operator/patient position
- Patient at 30 degrees to vertical
- Sit / stand in front at 8 o’clock position
- Have assistance present to restrain hands of child if necessary
Describe good principles when informing the child about LA
- Explanation is age dependent
- Tooth going to sleep, patient awake etc
- Explain and show topical gel
- Parents on board
Describe the technique of infiltration
- Pull cheek so mucosa is taut
- Position needle at muco-buccal fold beside tooth
- Gently insert needle at same time pulling taut tissue over needle
- Reassure and distract child
Name 6 components of notes to write up following administration of LA
- Local analgesic solution and vasoconstrictor, in date
- Drug concentrations
- Amount given in cartridges and mL
- Site of injections
- Abnormal reactions
- Post operative instructions given
Name 5 general complications of LA
- Psychogenic
- Allergy
- Drug interactions
- Infection
- Toxicity
What is the maximum dose of lidocaine for a child?
4.4mg / kg
How many mg of active ingredients is in one 2.2ml cartridge of 2% lidocaine?
44mg
Name 5 early localized complications of LA
- Pain
- Intravascular administration
- Failure of LA
- Facial nerve paralysis
- Haematoma formation (trismus)
Name 5 late localized complications of LA
- Self inflicted trauma
- Oral ulceration
- Long lasting anaesthesia
- Trismus
- Infection (introduction of bacteria at injection site)
Name 3 general factors which may contra indicate use of LA
- Young age
- Disability prevention cooperation
- Treatment required (duration, difficult access)
Name 3 medical history factors which may contra indicate use of LA
- Allergy
- Liver disease (reduce dose)
- Poor blood supply
Name 4 specific techniques which may contra indicate use of LA
- Bleeding disorders
- Incomplete root formation
- Trismus
- Epilepsy
