Local Anaesthetics

Question 0

What are the properties of amides e.g. Lidocaine, bupivicaine as local anaesthetics?

Answer 0

Longer duration of action

Metabolised by liver

Question 1

What are the properties of esters as local anaesthetics? E.g. Cocaine, procaine, tetracaine, benzocaine?

Answer 1

Short duration of action
Metabolised by plasma and liver pseudocholinesterases
Higher chance of allergies

Question 2

Which form of LA crosses the membrane best (charged or uncharged)?

Answer 2

Uncharged

Question 3

Which type of fibres (myelinated or non-myelinated) are blocked more easily by LA?

Answer 3

Myelinated fibres are blocked more easily

Question 4

What are the routes of local anaesthesia?

Answer 4

Infiltration (injection): procaine or lidocaine
Topical: benzocaine
Peripheral nerve block (injection into or around nerves)
Spinal (intrathecal): procaine, lidocaine
Epidural: procaine, lidocaine

Question 5

What are the neurological symptoms of LA toxicity?

Answer 5

Anxiety, confusion, tremors, convulsions

Question 6

What are the cardiac symptoms of LA toxicity?

Answer 6

Bradycardia, hypotension, arrhythmia, cardiac arrest

Question 7

What is the affect of adrenaline administration with LA?

Answer 7

Reduces the likelihood of systemic toxicity by causing vasoconstriction.

Question 8

What is used to treat LA toxicity?

Answer 8

Lipids