Local Anaesthesia

Question 1

A mechanism of local anaesthesia is the ‘specific receptor theory’, what does this cause?

Answer 1

• LA binds to receptor within Na+ channel (obstructs it)
  = reverse block of action potential

Question 2

Coaches and procaines are ________ and are metabolised by ____ in the ______

Answer 2

Amino esters
Pseudochloinesterase
Blood

Question 3

Idocaine and mepivocaine are forms of _______ and metabolised by ______

Answer 3

Amino amides
Liver

Question 4

In what scenario wouldn’t you prescribe adrenaline

Answer 4

Uncontrolled heart disease

Question 5

In what scenario wouldn’t you prescribe felypressin

Answer 5

Pregnancy

Question 6

What’s the benefit of using a vasoconstrictor over a vasodialator (4)

Answer 6

• less anaesthetic conc needed
• decreases blood toxicity
• increase length of action
• decrease bleeding

Question 7

How would you calculate the max number of local anaesthetic Cartridges

Answer 7

Max safe dose of LA (mg) x patient weight (kg) / amount of LA per cartridge

Question 8

What’s used as a topical anaesthetic for injections

Answer 8

Xylitol gel 5%

Question 9

Give 2 examples of vasoconstrictors

Answer 9

Adrenaline
Felypressin