LA for children Flashcards
What is surface anaesthesia
Anaesthesia of the surface tissues i.e. skin or mucous membranes
What is surface anaesthesia used for
To reduce pain of local anaesthesia injection
To reduce discomfort of venepuncture
For superficial soft tissue manipulation
What are the typs of surface anaesthesia
Physical (refrigeration)
Pharmacological (topical)
What is the technique for successful anaesthesia with topical
Dry area
Apply over limited area (use a cotton wool roll)
Apply for sufficient time: 2 mins
What depth of tissue can topical anaesthetise
2-3mm
When might topical be used
Pre-injection
Rubber dam clamp
Placing matrix band
Suture removal
Exfoliating primary teeth
Subgingival scaling
Incision of abscess
What topical anaesthetics can be used on skin (extraoral)
EMLA cream
Ametop gel
How do topical patches work
Incorporation of local anaesthetic into materials that adhere to the mucosa and allow slow release
Decreases the chance of the anaesthetic moving away from the application site
What are the advantages and disadvantages of topical jet injectors
Advantages
-Allows anaesthesia up to 1cm
-Bleeding diatheses where deep injections are contraindicated
-Sole means achieving LA
-Prior to conventional techniques
Disadvantages
-Could cause soft tissue damage if careless
-Frightening sight and sound
-Taste of solution
-Expensive!!!!
When might temperature have an effect on perceived discomfort
under 15 degrees
What are the properties of lidocaine 2% with 1:80,000 adrenaline
Amide
‘Gold Standard’ local anaesthetic
rapid onset of action and half-life = 1.5 -2hrs
suitable for infiltration, block, and surface anaesthesia
What advantages does LA with adrenaline have
More profound anaesthesia
Longer lasting pulpal anaesthesia
Haemorrhage control
What is an alternative vasoconstrictor from adrenaline
Felypressin/octapressin
What is the half life of lidocaine
1.5-2 hrs
What are the contrainfications to Lidocaine
If the patient has a heart block and no pace makers
Any allergy to LA/or to corn
Hypertension
impaired liver function
Why should 4% solutions be avoided
Higher risk of non-surgical paraesthesia
Shouldnt be used in patients with sickle cell anaemia or other haemoglobinopathies
What is the wand STA instrument
Computer-aided anaesthetic system
Allows for controlled adminstration of local anaesthetic
Can be used for infiltrations, blocks, intra-ligamentary and single tooth anaesthesia
What are the technique/modifications for injecting LA in children
Infiltration
Intra-ligamentary
Regional block
What sizes of needles are available to LA
Long - ID block 35mm yellow
Short - 25mm blue
Ultra short - 10mm purple
When can infiltrations be used
Primary teeth
Maxillary permanent teeth
Mandibular permanent anterior teeth
Before intrapapillary and intra-ligamental in posterior permanent teeth
Before palatal/lingual anaesthesia
What are the steps to giving a buccal/labial infiltration
Dry mucosa
Topical Anaesthetic (2 mins)
-Wipe off excess
Stretch mucosa
Distract patient
-gentle pressure or rubbing on lip, talking, singing
Insert needle
-ultra short or short needle
-Directed at apex of the tooth
Aspirate
Inject supra-periosteal as close as possible to apices of teeth
-0.5ml – 1ml should be suffice pulpal anaesthesia
How is intra-papillary infiltration carried out
Draw an imaginary line across the base of one of the interdental papillae
Draw a perpendicular line through the middle of the papillae
Insert the needle horizontally, to pass between the teeth on each side
Advance the needle 1-2mm and wait a few seconds, and advance again
Ensure the needle does not become obstructed on the inter-septal bone or emerge from the gingivae
After blanching is seen, insert the needle into the blanched area
How do you carry out an intraligamental injection
Intra-osseous via cancellous space via PDL
0.2ml per root – beware excess dose
More successful with a vasoconstrictor
Ultra short 30-gauge needle
30 degree to long axis of tooth in mesio-buccal gingival sulcus – advance until resistance
-Specialised syringe measured dose
-Conventional syringe – 0.2ml is width of bung
How is the mandibular foramen different in children compared to adults
Below the occlusal plane
Lower than in adults
How is does the needle approach the inferior alveolar and lingual nerve in children
Advances from the primary molars on the opposing side with the syringe held parrallel to the occlusal plane
What anatomical features should be remembered while administering nerve block
The needle inserted through the mucosa in the mandibular retromolar region lateral to the pterygomandibular raphe, midway between the raphe and the anterior border of the ascending ramus of the mandible, aiming for a point half-way between the operator’s thumb and finger
The height of insertion is around 5mm above the mandibular occlusal plane
The needle is advanced until the medial surface of the mandible is reached
In young children bone will be reached after about 15mm, therefore a 25mm needle can be used
In older children, bone may be reached at 25mm, therefore a 35mm needle is required
Once bone has been touched, the needle is withdrawn slightly until it is supra-periosteal, aspiration performed, and around 1.5ml of solution is deposited.
Withdraw halfway, aspirate again, and deposit the remaining solution for a lingual nerve block
How is the needle positioned for a mental/incisive nerve block
Advance needle in buccal sulcus toward region between apices of 1st and 2nd primary molars.
What are the advantages and disadvantages to a mental and incisive nerve block
Advantages
-very good soft tissue anaesthesia
Disadvantages
-Incisive nerve anaesthesia not as reliable as IDB
-Incisors may get crossover supply across midline so need a labial infiltration adjacent to tooth as well as this block
What is a psychogenic complication of anaesthesia and how to prevent it
Fainting - the chances of this happening are reduced by sympathetic management and administration of the anaesthetic to children in a semi-supine position
What are the maximum safe doses of each anaesthetic
Lidocaine 2% plain / with epinephrine:
4.4mg/kg
Prilocaine 4% plain / 3% w felypressin:
6.0mg/kg
Mepivicaine 3% plain / 2% w epinephrine:
4.4mg/kg
Articiane 4% with epinephrine
7.0mg/kg
Lidocaine
2% soln in 2.2ml cartridge contains 44mg
What is the max safe dose for a 5 year old 20kg child
20kg x 4.4 = 88mg = 2 cartridges
What a 5 year old 20kg child what is the safe dose of prilocaine and articaine
Prilocaine
3% soln in 2.2ml cartridge contains 66mg
Max safe dose is 6.0mg/kg
20kg x 6 = 120 mg = 2/11 short of 2 cartridges
Articaine
4% soln in 2.2ml cartridge contains 88mg
Max safe dose is 7mg/kg
20kg x 7 = 140mg= 1.6 Cartridges
What are the effects of LA toxicity
Cardiovascular
-low levels – stimulant
-high levels - circulatory collapse
CNS
-Depressant leading to unconsciousness and respiratory arrest
Methaemoglobinemia
-Cyanosis associated with lethargy and respiratory distress
-Ferrous iron of normal hemoglobin is converted to the ferric form, which cannot combine with
-Prilocaine
What are the steps to treating toxicity
Stop treatment
Provide BLS
Call for medical assistance
Protect patient from injury
Monitor vitals
What are early localised complications of LA
Pain
Failure of LA
Motor nerve paralysis
Haematomaformation
What are late localised complications of LA
Self inflicted trauma
Oral ulceration
Long lasting anaesthesia
Trismus
Infection
Developmental defects
What are behaviour managed techniques to use when giving LA to a child
Distraction
Tell-show-do
Acclimatisation
Role modelling
Voice control
