General anaesthetics Flashcards Preview

PM3B - Anaesthetics and muscle relaxants > General anaesthetics > Flashcards

Flashcards in General anaesthetics Deck (17)
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1

What is the importance of anaesthesia?

Enables surgeons more time allowing increased accuracy
Able to enter more high risk areas such as the abdomen/chest/brain

2

What are the aims of general anesthesia? (3)

Loss of consciousness
Analgesia
Muscle relaxation

3

How do you measure anaesthetic action?

MAC (minimum alveolar concentration)

4

Define MAC

The concentration of vapour in the lungs that is needed to prevent movement in 50% of subjects exposed to painful stimuli

5

What are the central actions of general anaesthetics? (2)

Inhibit excitatory channels e.g. glutamate
Activate inhibitory channels e.g. GABAa

6

What are the peripheral actions of general anaesthetics? (3)

Cardiovascular - circulatory depression
Respiratory - respiratory depression
Muscular - relaxation

7

What are the FIVE stages of general anaesthesia?

Pre medication
Induction
Maintenance
Muscle relaxation
Pain relief

8

What are the aims of pre medication? (3)

Reduce anxiety and pain
Promote amnesia
Reduce vagal reflexes

9

What drug classes are there for pre medication? Give examples (4)

Benzodiazepines - Diazepam
mAChR antagonist - Atropine
Opioid receptor agonist - Morphine
PPI - Metoclopramide

10

What are the aims of induction?

Induce loss of consciousness

11

Name TWO drug inducers

Propofol
Barbituate e.g. Sodium Thiopental

12

Which inducer is favoured and why?

Propofol - rapid metabolism and lack of hangover effect

13

How does ketamine work?

Inhibits excitatory NMDA glutamate receptors

14

What is the aim of maintenance?

Maintain loss of consciousness

15

Name TWO drugs used for maintenance

Halothane
Nitrous Oxide

16

What drugs are used for pain relief?

Opioids like morphine or fentanyl

17

What are the TWO mechanisms of muscle relaxation? Give examples

Competitive blockers - Atracurim
Depolarizing blockers - Succinylcholine