Pharmacology - General Principles

Question 1

what are the three subtypes of anaesthesia

Answer 1

general
regional
local

Question 2

describe general anaesthesia

Answer 2

loss of consciousness
complete lack of awareness
centrally acting drugs

Question 3

describe regional anaesthesia

Answer 3

nerve and plexus blocks

effects distal site of nerve

Question 4

describe local anaesthetic

Answer 4

injected directly into tissues

has effect at site of injection

Question 5

what are functions of a modern anaesthetic machine

Answer 5

regulates fresh gases 
delivers precise concentrations of gas 
CO2 removal 
mechanical ventilation using microcompressor 
monitors patient

Question 6

what makes up the ‘triad of anaesthesia’

Answer 6

hypnosis
analgesia
muscle relaxation

Question 7

what is hypnosis

Answer 7

unconsciousness

Question 8

what IV agents are used for hypnosis

Answer 8

propofol
ketamine
thiopental sodium
etomidate

Question 9

what inhaled agents are used for hypnosis

Answer 9

sevoflurane
desflurane
isoflurane
nitrous oxide

Question 10

what drugs are used for analgesia

Answer 10

fentanyl
alfentanil
remifentanil
morphine

Question 11

what is the function of analgesics in operations

Answer 11

pain relief
suppress reactions/reflex response to noxious stimuli like tachycardia and movement
prevents arousal
can contribute to hypnotic effect

Question 12

what drugs are used as muscle relaxants

Answer 12

benzodiazepines like midazolam

Question 13

what are general anaesthetic agents

Answer 13

drugs providing unconsciousness, muscle relaxation, pain relief, suppress neuronal activity

Question 14

what are common IV general anaesthetic agents

Answer 14

thiopentone

Propofol

Question 15

what are features of IV anaesthetic agents

Answer 15

lipophilic
fast acting
leave circulation quickly
enter muscle and then fat

Question 16

what drugs are used as inhaled anaesthetic agents

Answer 16

halogenated hydrocarbons

Question 17

what does a lower MAC value of a drug mean

Answer 17

lower value = higher potency

Question 18

what does a TCI pump system do

Answer 18

device that gives a real time ‘guestimate’ of concentration of IV agents

Question 19

how do general anaesthetics work

Answer 19

depress CNS 
(except ketamine)

Question 20

what are physiological effects of general anaesthetics

Answer 20

reduces synpathetic outflow 
inotropic effect on heart 
vasodilation 
reduced venous return and CO 
reduce hypoxic drive 
decrease tidal volume 
increase resp rate

Question 21

what are common local anaesthetics

Answer 21

lingocaine
bupivacaine
ropivacaine

Question 22

how do local anaesthetics work

Answer 22

block Na channels

Question 23

what nerves are harder for local anaesthetic to penetrate

Answer 23

motor nerves

pain nerves are easier

Question 24

what is the major risk of using local anaesthetics

Answer 24

incorrect administration - very toxic

Question 25

what are symptoms of local anaesthetic toxicity

Answer 25

circumoral and lingual numbness and tingling 
lightheaded
tinnitus 
visual disturbances 
muscular twitching 
drowsiness 
muscular twitching 
drowsiness 
CVS depression 
Convulsions 
Comma 
Cardiopulmonary arrest

Question 25

what are symptoms of local anaesthetic toxicity

Answer 25

circumoral and lingual numbness and tingling 
lightheaded
tinnitus 
visual disturbances 
muscular twitching 
drowsiness 
muscular twitching 
drowsiness 
CVS depression 
Convulsions 
Comma 
Cardiopulmonary arrest

Question 26

What is the anaesthetic triad?

Answer 26

1. hypnosis - unconsciousness
2. analgesia - pain relief
3. muscle relaxant - relaxes skeletal muscle.

• local anaesthetic = pain relief (+ muscle relaxant)
• general anaesthesia = hypnotic (+ muscle relaxant and pain relief)
• opiates = pain relief (+ hypnotic)
• muscle relaxant = relaxes muscles only

You can give analgesia on its own, you can give hypnotic on its own but NOT muscle relaxant.