L09: Local Anaesthetics

Question 1

What is the definition of local anaesthetics

Answer 1

Local anaesthesia reversible block nerve conduction when applied to an area for a procedure to be carried out without the loss of consciousness

Question 2

Which sensory receptor detects pain

Answer 2

Nociceptors

Question 3

What is the role of local anaesthetics to reduce pain

Answer 3

Interfere with voltage-gated sodium channels to stop action potential from occurring and pain

Question 4

What is the end name for local anaesthetics

Answer 4

-Caine

Question 5

What is the common chemical structure of all local anaesthetics

Answer 5

Aromatic ring
Amide group
Linkage group

Question 6

What bond does the linkage group involve

Answer 6

Amide or ester bonds

Question 7

Does an amide or ester bond get metabolised quick

Answer 7

Ester

Question 8

Name 4 local anaesthetics

Answer 8

Procaine
Lidocaine
Prilocaine
Bupivacaine

Question 9

What is the linkage group of procaine

Answer 9

Ester

Question 10

What is the linkage group of lidocaine

Answer 10

Amide

Question 11

What is the linkage group of prilocaine

Answer 11

Amide

Question 12

What is the linkage group of bupivacaine

Answer 12

Amide

Question 13

Which named local anaesthetics has the shortest duration

Answer 13

Procaine

Question 14

Which named local anaesthetics has a medium duration

Answer 14

Lidocaine

Prilocaine

Question 15

Which local anaesthetics has the longest duration

Answer 15

Bupivacaine

Question 16

What is the property of the aromatic ring

Answer 16

Lipid soluble

Question 17

What does a lipid soluble aromatic ring mean

Answer 17

The drug can pass through the membrane

Question 18

What is an amine group

Answer 18

NH2

Question 19

What can happen to the amine group which makes the drug non-lipid soluble

Answer 19

Add H+

Question 20

What determines the status of the amine group

Answer 20

Acidity

Question 21

What happens during pain at nociceptors in normal circumstances without general anaesthetics

Answer 21

At a pain stimulus Sodium voltage gated ion channels open
Sodium influx occurs
Depolarisation occurs

Question 22

What happens during pain with local anaesthetics

Answer 22

1) The unionised form of local anaesthetics diffuses through the lipid membrane
2) the pH inside the cell sets up an equilbrium to get an ionised form of local anaesthetics
3) charged local anaesthetics blocks the sodium voltage gated channels so depolarisation cannot occur

Question 23

What is the block of sodium voltage gated ion channel by local anaesthetics called

Answer 23

Use-dependent block

Question 24

Which factors affect the action of local anaesthetics

Answer 24

Infection/ acidic conditions

Question 25

How does increasing acidity affect local anaesthetics

Answer 25

Increase in local anaesthetic causes an ionised form of local anaesthetic so it cannot get into the cell This gives poor anaesthesia

Question 26

What is the best way of getting a greater area anaesthetised

Answer 26

Closer to the spinal cord

Question 27

What are the 5 ways of administrating local anaesthetics

Answer 27

``` Topical anaesthesia Infiltration anaesthesia Nerve block anaesthesia Epidural anaesthesia Spinal anaesthesia ```

Question 28

What is topical anaesthesia

Answer 28

You rub the drug on a thin membrane

Question 29

What is infiltration anaesthesia

Answer 29

Injection onto wound

Question 30

What is nerve block anaesthesia

Answer 30

The anaesthesia covers a lot of axons

Question 31

What is epidural anaesthesia

Answer 31

Anaesthesia into the epidural space

Question 32

What is spinal anaesthesia

Answer 32

Anaesthesia at the spinal cord

Question 33

What are the common side effects of local anaesthetics

Answer 33

Allergic reaction due to preservatives within the drug | Respiratory failure if injected into the wrong place such as vessels

Question 34

Which drugs are administered with local anaesthetics

Answer 34

Vasoconstrictors

Question 35

Name a vasoconstrictor

Answer 35

Adrenaline

Question 36

What is the purpose of giving adrenaline with local anaesthetics

Answer 36

Stops vasodilation and keeps the drug where we have put it and makes it last longer

Question 37

What are the 4 properties of a good anaesthetics

Answer 37

Reversible Block nerve conduction in nociceptive neurones Long lasting Low toxicity

Question 38

Which sensory neurones have the highest sensitivity to local anaesthetics

Answer 38

Alpha delta | C

Question 39

Which neurones have low sensitivity to local anaesthetic

Answer 39

Somatic motor neurones

Question 40

Is alpha delta neurone myelinated or unmyelinated

Answer 40

Myelinated