LA for Children Flashcards
What are the uses of LA in children?
Operative pain control
Hemorrhage control
Diagnostic tool
What is an example of physical LA?
(refrigeration anaesthesia)
By reducing the temperature
Ethyl chloride (rarely used as LA agent in children)
highly flammable
What are the types of topical/surface anaesthetics?
- Intraoral topical agents
- Topical anaesthetics for skin
- Controlled release devices (patches)
- Jet injectors
What are the two non-pharmalogical methods of LA?
TENS (Transcutaneous Electrical Nerve Stimulation)
Hypnosis
What are the 2 lidocaine solutions usually used?
- Lidocaine 2% with 1:80000 epinephrine/adrenaline (amide) (Lignospan®, Xylocaine®)
- Lidocaine 2% plain (amide) (shorter acting as no vasoconstricter)
What is the prilocaine solution usually used and when is it contraindicated (vascoconstrictor)?
- Prilocaine (Citanest®) 3% with felypressin (also known as octapressin) 0.03IU/ml (amide)
octapressin can induce early labour (therefore do not use for pregnancy)
What is the articaine solution usually used?
Articaine 4% (Septanest®) with 1:100 000 adrenaline (amide)
What is lidocaine used for and what are the contraindications?
suitable for infiltration, block, and surface anesthesia
anti-arrhythmic drug
Heart block and no pace-maker. Allergy to LA (or to corn), hypotension, impaired liver function.
Which has a shorter half-life articaine or lidocaine?
articaine - 20 mins
lidcocaine - 1.5/2 hours
Which LAs have a benzene group and which have a thiophene?
prilocaine, lidocaine = benzene
thiophene = articaine (with additional ester group)
What is articaine used for?
*More effective for mandibular infiltrations than lignocaine
*Lignocaine and articaine are equally effective as blocks.
Why is lidocaine used for block?
4% articaine carries higher risk of non-surgical paraesthesia
What are the contraindications for articaine?
Avoid in sickle cell patients (and other haemoglobinopathies)
What is the effect of adrenaline?
Adrenaline binds to alpha-receptors in the peripheral vasculature causing vasocontriction. It also causes tachycardia , due to binding with Ɓ1-adrenergic receptors in the heart wall.
When is adrenaline contraindicated?
no need to avoid LA without adrenaline (which is less effective) unless BP> 200mmHg (systolic) and/or (diastolic) >115mmHg
have caution with patients on diuretics (“water tablet” used to decrease BP by flushing salt out of body)- use adrenaline free LA to avoid risk of reduction in potassium concentration)
What are 3 techniques of LA in children?
infiltration
intraligamentary
regional block
What are the 3 different needle sizes used for?
long - ID block
short - infiltration
ultra short - infiltration
What is the infiltration used for?
- 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
How is lingual/palatal anaesthesia carried out?
Ultra short 90 degrees to surface Approach via anaesthetised buccal interdental papilla
What is intraligamental LA used for?
(single tooth, injected into PDL)
- to supplement infiltrations
- may eliminate need for block
How can intraligamental discomfort by reduced in a child?
- Small buccal infiltration
- Papillary injection
What syringe in used for a intraligamental?
normal syinge with ultra short needle
custom made syringes
How is intraligamental LA carried out?
needle and gauge
- Interosseous via cancellous space via PDL
- 0.2ml per root–beware excess dose
- More successful with a vasoconstrictor
- Ultra short 32 gauge needle
- 30 degree to long axis of tooth in mesiobuccal gingival sulcus - advance until resistance
What is the wand used for?
*Uses computerised flow of local anaesthetic
*Can be used as a method of intraligamental LA for single tooth anaesthesia
*Can also be used for infiltration and block anaesthesia.
Where in the mandibular foremen in children?
below occlusal plane
lower than in adults
Where is the location for a regional IAB and lingual nerve block?
Approach direct from primary molars of opposite side.
lateral to pterygo mandibular raphe and medial to ascending ramus
How is a mental block carried out?
Advance needle in buccal sulcus toward region between apices of 1st and 2nd primary molars.
What are advantages/disadvantages of a 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 a labial infiltration adjacent to tooth as well as this block
Where is the mental foremen in children?
more anterior in children than lateral in adults
What block is hardly used?
maxillary
This is because the wide area of anesthesia resulting from maxillary nerve block (including the dural, temporal, and zygomatic regions; the mucosa of the maxillary sinus; and the maxillary teeth and their soft tissues) is often not needed
What is used to block the nasopalatine and greater palatine nerves and how?
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 may cause allergy in LAs?
- Metabisulphite (E223) preservative, antiseptic
- Latex –rubber bung
- Methyl parabens Preservative, (E218) found in blueberries.
What can LA toxicity do?
- CNS
– Depressant leading to unconsciousness and respiratory arrest - Methaemoglobinaemia
– condition where an abnormal amount of hemoglobin is oxidized to Fe3+ instead of Fe2+, reducing its ability to transport oxygen in the blood.
– Caused by prilocaine, lidcaine articaine, benzocaine
What is the safe dose of lidocaine, prilocaine, mepivicaine and articaine?
Lidocaine: 4.4 mg/kg
Prilocaine: 6 mg/kg
Articaine: 7 mg/kg
What is the safe dose of lidocaine for a 20kg child?
2.2ml cartridge contains 44mg
– 2% soln in 2.2ml cartridge contains 44mg
– Max safe dose is 4.4mg/kg or 1/10th cart /kg
20kg x 4.4 = 88mg = 2 cartridges
What is the safe dose of articaine for a 20kg child?
2.2mll cartridge contains 88mg
- 4% soln in 2.2ml cartridge contains 88mg
- Max safe dose is 7mg/kg
-
88/7 cart/kg*
20kg x 7 = 140mg= 1/5 short of 2 cartridges
How can you prevent complications in LA?
- Aspiration
- Slow injection
- Dose limitation
What are the steps for treatment of toxicity?
- Stop dental treatment
- Provide basic life support
- Call for medical assistance
- Protect patient from injury
- Monitor vital signs
What are late localised complications?
- Self inflicted trauma causing oral ulceration from chewing
- Long lasting anaesthesia
- Trismus
- Infection
- Developmental defects
Where does pain occur?
– intraepithelial; subperiosteal;
– nerve trunk; intravascular
Why for IDB be avoided in bleeding disorders?
can cause haematoma in retromolar and pterygoid area which is fatal and can go unnoticed
Why should you take care with a patient with liver disease?
some LAs are metabolised in the liver therefore amide dose reduction
Behaviour techniques in children?
Be empathetic
Positive reinforcement
Tell-show-do
Acclimatization
Desensitization
Voice control
Distraction
Role modeling
