Local Anaesthetic In Children

Question 1

Define pain

Answer 1

Unpleasant emotional response usually by noxious stimulus and transmitted over a specialised neural network to the CNS, where it is interpreted as such

Question 2

Define local anaesthesia

Answer 2

Reversible loss of sensation in a circumscribed area of the body caused by depression of an excitation in nerve ending or inhibition of conduction process in peripheral nerves

Question 3

Various methods of inducing LA

Answer 3

• mechanical trauma
• low temperature
• anoxia
• neurological agent - alcohol
• chemical agent - LA

Question 4

Properties of LA

Answer 4

• non irritating
• reversible
• toxicity
• effective whether it is injected into tissues or applied locally to mucous membranes
• short duration of onset
• adequate duration of anaesthetic action
• should be free of allergens ideally
• stable in solution and readily undergo bio transformation in the body
• should be sterile or capable of sterilisation by heat without deterioration

Question 5

Classification of LA - Esters

Esters of benzoic acid

Answer 5

Esters of benzoic acid
- butacaine
- cocaine
- benzocaine
- hexylcaine
- tetracaine

Question 6

Classification of LA - Esters

Esters of para-amino benzoic acid

Answer 6

Esters of para-amino benzoic acid
- chloroprocaine
- procaine
- propoxycaine

Question 7

Classification of LA - Amides

Answer 7

• articaine
• bupivacaine
• dibucaine
• etidocaine
• lidocaine
• mepivacaine
• prilocaine

Question 8

Classification of LA - Quinoline

Answer 8

Centbucridine

Question 9

Duration of action

Ultra short acting (<30mins)

Answer 9

• 2% plain lidocaine
• 3% plain mepivacaine
• 4% prilocaine

Question 10

Duration of action

Short acting (45-75mins)

Answer 10

• procaine
• chloroprocaine

Question 11

Duration of action

Medium acting (90-150 mins)

Answer 11

• lidocaine
• prilocaine

Question 12

Duration of action

Long acting (>180 mins)

Answer 12

• bupivacaine
• ropivacaine
• tetracaine

Question 13

Strategies for pain control in paediatric dentistry

Answer 13

• topical analgesia
• local analgesia
• inhalation sedation / relative analgesia
• GA

Question 14

LA complacency

Answer 14

• essential for operative dentistry
• dentists are good at LA
• LA maximum dosage - do we know them?
• LA is routine from dentist POV

Question 15

2% lignocaine / adrenaline max dose?

Answer 15

4.4mg / kg

2% lignocaine = 2g/100ml
= 2000mg / 100ml
= 20mg / ml
= 1mg / 0.05ml
= 4.4mg / 0.22ml
= one tenth 2.2ml cart

Therefore max dose is one tenth 2.2ml cartridge / kg

Question 16

3% prilocaine / fellypressin max dose?

Answer 16

6.6mg / kg

3% citanest = 3g / 100ml
= 3000mg / 100ml
= 30mg / ml
= 1mg / (1/30ml)
= 6.6mg / 0.22ml
= one tenth 2.2ml cart

Therefore max dose is one tenth 2.2ml cartridge / kg