Critical Care

Question 1

What is anesthesia

Answer 1

total/partial loss of sensation

Question 2

What is anesthetics

Answer 2

agents that induce anaesthesia

Question 3

Name 4 different types of anesthesia

Answer 3

1. Topical: Render part of the body surface insensitive to noxious stimuli (creams, ointments, and sprays)
2. Local: Small area of the body is rendered insensitive to noxious stimuli without loss of consciousness
3. Regional: A larger area of the body is rendered insensitive to noxious stimuli without loss of consciousness (brachial plexus block, Bier’s block and spinal anesthesia)
4. General: Considered to have 3 primary goals. The patient is rendered insensitive to noxious stimuli - reversible loss of consciousness - muscle relaxation

Question 4

What factors influence the type of anesthetic used?

Answer 4

1. Procedure duration
2. Procedure location
3. ASA status
4. Surgeon/anesthetist preference
5. Patient preference

Question 5

How do local anesthetic agents work?

Answer 5

1. They cause reversible inhibition of cell membrane Na+ channels, preventing the generation and propagation of action potentials. Na+ channels are proteins, the greater the protein affinity of the LA, the greater its efficacy. LAs with greater lipid solubility are more potent and have a longer duration of action.

Question 6

How are LAs classified?

Answer 6

1. Amides: lidocaine, bupivacaine and prilocaine
2. Esters: cocaine and procaine