Local Aneasthesia In Children Flashcards
What is the definition and function of surface anaesthesia?
- To anaesthetise the surface tissues (skin or mucous membranes)
- To reduce pain of La injection
What are two different types of surface anaesthesia?
- Physical (refrigeration) anaesthesia
2. Pharmacological (topical) anaesthesia
Give an example of physical anaesthesia and describe Advantages/disadvantages
- Ethel chloride
- reduces temperature
- difficult to direct stream of liquid accurately
- inadvertent contact with vital teeth produces discomfort
- highly flammable
List some different types of toucan anaesthesia
- Intra oral topical agents
- Topical anaesthetics for skin
- Controlled release devices
- Jet injectors
What depth of tissue is anaesthetised by intraoral topical agents?
2-3mm
How should topical anaesthesia be applied?
- Applied over a dry area
- Apply over a limited area using cotton wool roll
- Apply for sufficient time (2 mins)
List some different preparations of topical anaesthetic
- Lidocaine:
- 2% gel
- 10% spray
- 5% ointment - Benzocaine
- 20% gel
What are used of intra oral topical anaesthesia?
- Pre injection
- Rubber dam clamp
- Placing matrix band
- Suture removal
- Exfoliating primary teeth
- Sub gingival scaling
- Incision of abscess
Name two topical anaesthetics used for skin
- EMLA cream
- 5% eutectic mixture of prilocaine (amide) and lidocaine (amide)
- needs to be applied for 45 minutes
- useful prior to general anaesthesia or IV sedation - Ametop gel
- tetracaine (amethocaine) 4% gel (Ester)
- faster onset than EMLA
Name a topical control release device and describe how it works
- Patches
- incorporation of LA into materials that adhere to the mucosa and allow slow release
- decreases the chance of anaesthetic moving away from the application site
What is TENS and how does it work?
- TENS = transcutaneous electrical nerve stimulation
- blocks large myelinated nerve fibres and closes the gate to central transmission of smaller unmyelinated nerve fibres
What are advantages and uses of TENS?
Controlled by patients over 10 years old
Uses:
- restorations
- primary extractions
- pre LA
Briefly describe lidocaine
- Common local anaesthetic
- Anti-arrhythmic drug (suppressed abnormal heart rhythms)
- Rapid onset of action and half life
- Suitable for infiltration, block and surface anaesthesia
Why is epinephrine added to lidocaine?
- Causes vasoconstriction of arteries, reducing bleeding and increasing the duration of anaesthesia
When SHOULD’NT lidocaine be used?
In patients with:
1. Heart block and no pace maker
- Allergy to LA or corn
- Hypotension
- Impaired liver function
What is the half life of lidocaine?
1.5-2 hours
Why does articaine have a lower risk of systemic toxicity than other LA?
It is hydrolysed by blood quicker
What is an advantage of articaine in comparison to lidocaine?
Articaine is much more effective for mandibular infiltrations
What is the half life of articaine?
20 min
When SHOULD’NT articaine be used?
- Sickle cell patients
- other blood disorders
What are 3 different techniques for LA I’m children?
- Infiltration
- Intraligamentary
- Regional block
What are used of LA infiltration?
- Anaesthesia in primary teeth
- Anaesthesia in maxillary permanent teeth
- Anaesthesia in mandibular permanent anterior teeth
- Prior to intrapapillary and then intraligamental anaesthesia in posterior permanent teeth
- Prior to intrapapillary and palatal/lingual anaesthesia
Describe LA infiltration technique
- Dry mucosa
- Topical anaesthetic (2 mins)
- Wipe off excess topical anaesthetic
- Stretch mucosa
- Distract patient (gentle pressure or rubbing on lip, talking, singing)
- Insert needle (ultra short or normal 30 gauge)
- Aspirate
- Inject supra periosteal as close as possible to apices of teeth
How do you achieve lingual anaesthesia?
- Ultra short 90 degrees to surface
2. Approach via anaesthetised buccal interdental papilla
What actions can you take to reduce the discomfort of an intraligamentary injection in a child?
- Small buccal infiltration
2. Papillary injection
Describe how to administer an intra ligamentary injection. Include:
- location
- equipment
- technique
Location:
- intraosseous vía cancellous space via PDL
Equipment:
- ultra short 32 gauge needle
- conventional syringe (0.2ml bung width)
- much more successful with vasoconstrictor
- specialised syringe measures dose
Technique:
- 0.2ml of solution per root
- 30 degree angle to long axis of tooth in mesiobuccal gingival sulcus - advance until resistance is met
Describe where the mandibular foramen is in small children?
- Below occlusal plane
2. Lower than in adults
Describe how to find the correct location for a regional block (IDN and lingual nerve)
- Place thumb on coronoid notch for reference
- Approach direct from primary molars of opposite side
- Place needle lateral to pterygomandibular raphe and medial to ascending ramus
Describe how to give a mental block
- Technique
- advance needle in buccal sulcus toward region between apices of 1st and 2nd primary molars
What are advantages and disadvantages of Mental 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 labial infiltration adjacent to tooth as well as this block
How does the mental foramen differ in children and adults?
Faces more anteriorly in children
What regional blocks can be achieved in the maxillary arch and how is this achieved?
- Greater palatine and nasopalatine blocks
- can be achieved by infiltrating LA through anaesthetised buccal papilla and ‘chasing’ the anaesthetic through to the palatal mucosa
What are some generalised complications that accompany La?
- Psychogenic (stress)
- Allergy
- Toxicity
- Drug interactions
- Infections
What main simple actions are taken to avoid LA complications?
- Aspiration
- Slow injection
- Dose limitation
List the actions (in order) you would take to treat LA toxicity
- Stop dental treatment
- Provide BLS
- Call for medical assistance
- Protect patient from injury
- Monitor vital signs
List 6 late LA complications
- Self inflicted trauma
- Oral ulceration
- Long lasting anaesthesia
- Trismus
- Infection
- Developmental defects
What are early localised complications of LA?
- Pain:
- intraepithelial; subperiosteal
- nerve trunk; intravascular - Intravascular injection
- arterial; venous - Failure of LA
- anatomy
- pathology
- technique - Motor nerve paralysis
- Haematoma formation
What are contraindications to LA?
- In bleeding disorders, avoid IDB
- Allergy
- Acute infection
- Care in liver disease = amide dose reduction
What are the safe doses for:
- Lidocaine
- Prilocaine
- Mepivicaine
- Articaine
- Lidocaine 2% plain/epinephrine
- 4.4mg/kg - Prilocaine 4% plain/3% w felypressin
- 6mg/kg - Mepivicaine 3% plain/ 2% w epinephrine
- 4.4mg/kg - Articaine 4% with epinephrine
- 7 mg/kg
