anaesthetics

Question 1

Objectives for General Anaesthetics

Answer 1

A temporary loss of conciousness/sensation

Analgesia

Muscle relaxation

Question 2

The predominant effect of General Anaesthetics is on____________ , rather than action potential propogation

Answer 2

SYNAPTIC TRANSMISSION

Question 3

Anaesthetic are thought to block excitatory receptors such as?

Answer 3

Glutamatergic

Cholinergic

Serotonergic (5HT)

Question 4

Generally enhance the function of inhibitory synaptic receptors such as?

Answer 4

GABA-A receptors

TREK potassium channels

Question 5

What Group Provides anxiolysis; sedation; reduction in muscle tone; anterograde amnesia; anticonvulsant effects

Answer 5

Benzodiazepines

Question 6

List the functions of Analgesia

Answer 6

Opioids remain the mainstay due to the severity of surgical pain

Used pre- and post-operatively, e.g. Morphine; fentanyl

Question 7

List the Functions of Muscarinic antagonists

Answer 7

Prevent excessive cholinergic effects such as salivation and bronchial secretions. Also protect the heart from arrhythmias caused by some anaesthetics like halothane

Question 8

Antiemetic drugs are used for ______

Answer 8

Prevent post-operative vomiting

Question 9

Neuromuscular blockers are used for?

Answer 9

Prevention of reflex-induced muscle contractions for abdominal/thoracic surgery

Tracheal intubation

NMBs block synaptic transmission at the neuromuscular junction

Question 10

What are the two different classes Neuromuscular blockers and there functions?

Answer 10

Non depolarising: act by blocking nACh receptors directly

Depolarising: act as agonists at nACh receptors. Initial effect is depolarisation

Question 11

Benefits of Intravenous

Answer 11

Act rapidly (~ 20-30 seconds)

Less traumatic for patients

Short duration of action-about 10 minutes for each dose. Not suitable for long-term maintenance of anaesthesia

Question 12

Local anaesthetics block nerve conduction by blocking _______

Answer 12

Na channels

Question 13

Whats the mechanism of action in local anaesthesia?

Answer 13

Sodium ions cannot flow into the neuron, thus the potassium ions cannot flow out, thereby inhibiting the depolarization of the nerve

Question 14

Name the different types of Local anaesthesia

Answer 14

Local infiltration
Surface Anaesthesia
Topical block
Nerve block
Epidural Anaesthesia
Spinal Anaesthesia

Question 15

What is the mechanism and use of Local infiltration?

Answer 15

Nerve endings in the skin and subcutaneous tissues are blocked by direct contact with a local anaesthetic

Used primarily for surgical procedures involving a small area of tissue

Question 16

What is the mechanism and use of Surface anaesthesia?

Answer 16

Application of a local anesthetic to skin or mucous membranes.

Surface anesthesia is used to relieve itching, burning, and surface pain

Question 17

What is the mechanism and use of Topical block

Answer 17

Anaesthetic agent applied directly to mucous membrane surface (cornea; respiratory tract; oral mucosa)

Used during examination procedures (often in spray form)

Question 18

What is the mechanism and use of Nerve block

Answer 18

Local anaesthetic is injected around a nerve that leads to the operative site.
More concentrated forms of local anaesthetic solutions are used for this type of anesthesia.

Used for surgery or dentistry

Question 19

What is the mechanism and use of Epidural Anaesthesia

Answer 19

Accomplished by injecting a local anaesthetic into the epidural space.

The epidural space is above the dura and surrounds the spinal cord.

Question 20

What is the mechanism and use of Spinal Anaesthesia

Answer 20

Local anesthetic is injected into the subarachnoid space of the spinal cord to act on spinal roots and spinal nerves
Acts more quickly than epidural anaesthesia

Used for surgery to abdomen, pelvis or leg if GA is contra-indicated