Anaesthetics Pain

Question 1

what are the patient benefits for treating pain?

Answer 1

physical - better sleep and appetite
fewer medical complications
psychological - reduced suffering, less depression and anxiety

Question 2

what are the family benefits for treating pain?

Answer 2

improved functioning as a family member

able to keep working

Question 3

what are the societal benefits for treating pain?

Answer 3

lower health costs

able to contribute to community

Question 4

how can you classify pain?

Answer 4

duration - acute/chronic/acute on chronic
cause - cancer/non-cancer
mechanism - nociceptive/neuropathic

Question 5

compare acute and chronic pain

Answer 5

Acute - recent onsent, probably limited duration

Chronic - lasts > 3 months, beyond normal healing, no identifiable cause

Question 6

compare nociceptive and neuropathic pain

Answer 6

In nociceptive pain there is obvious tissue injury or illness. It is also called physiological or inflammatory pain. Nociceptive pain serves a protective function. This type of pain is sharp or dull and well localised.

Neuropathic pain results from nervous system damage or abnormality. Tissue injury may not be obvious. Neuropathic pain does not serve a protective function. This type of pain may be described as: burning, shooting ± numbness, pins and needles. It is not well localised.

Question 7

what are the 4 steps of pain physiology?

Answer 7

periphery
spinal cord
brain
modulation

Question 8

describe the periphery part of pain physiology

Answer 8

• Tissue injury
• Release of chemicals e.g. PGs, substance P
• Stimulation of nociceptors
• Signal travels in A𝛿 or C nerve to spinal cord•

Question 9

describe the spinal cord part of pain physiology

Answer 9

• Dorsal horn is the first relay station
• A𝛿 or C nerve synapses with second nerve
• Second nerve travels up on contralateral side of spinal cord

Question 10

describe the brain part of pain physiology

Answer 10

• Thalamus is the second relay station
• Connections to many parts of the brain
o Cortex – expecting it to hurt
o Limbic system
o Brainstem – pain response
• Pain perception occurs in the cortex

Question 11

describe the modulation part of pain physiology

Answer 11

• Descending pathway from brain to dorsal horn
• Usually decreases pain signal
• People who do this more effectively experience less pain
• Serotonin and dopamine reuptake

Question 12

how does neuropathic pain come about. give examples of it

Answer 12

• Abnormal processing of pain signal
• Nervous system damage or dysfunction
• Needs to be treated differently
• Examples
o Nerve trauma, diabetic pain (damage)
o Fibromyalgia, chronic tension headache (dysfunction)
• Common after thoracic surgery
o Intercostal nerves pulling and retraction
• Breast surgery

Question 13

examples of simple analgesics

Answer 13

paracetamol

NSAIDs

Question 14

examples of mild opioids

Answer 14

codeine, dihydrocodeine

Question 15

examples of strong opioids

Answer 15

morphine, oxycodone, fentanyl

Question 16

what other drugs (classes) can be used to treat pain?

Answer 16

tramadol
antidepressants - amitriptyline, duloxetine
anticonvulsants - gabapentin
ketamine
local anaesthetics
topical agents - capsaicin

Question 17

what class of drug is tramadol?

Answer 17

mixed opiate and 5HT/NA reuptake inhibitor

Question 18

what class of drug is ketamine?

Answer 18

NMDA receptor antagonist

Question 19

treatments for periphery pain causes

Answer 19

non-drug RICE
NSAIDS
local anaesthetics

Question 20

treatments for spinal cord pain causes

Answer 20

non-drug acupuncture, massage, TENS
local anaesthetics
opioids
ketamine

Question 21

treatments for brain pain causes

Answer 21

non-drug psychological, CBT
paracetamol
opioids
amitriptyline
clonidine

Question 22

describe paracetamol

Answer 22

• Cheap, safe
• Oral, IV, rectal
• Good for
o Mild pain – alone
o Mod-severe pain – in combination
• Liver damage in overdose

Question 23

give examples of NSAIDs

Answer 23

aspirin
ibuprofen
diclofenac

Question 24

what are NSAIDs useful for?

Answer 24

nociceptive pain give with paracetamol

Question 25

why must NSAIDs be used with care in asthmatics?

Answer 25

o Prostaglandin synthase inhibitor can go down into prostacyclin cycle resulting in wheeze o Can push into status asthmaticus (rare) but if on lots of nebs etc don’t

Question 26

what kind of pain is codeine useful for

Answer 26

mild-moderate acute nociceptive pain best with paracetamol

Question 27

what are the side effects of codeine?

Answer 27

constipation | nausea

Question 28

what is codeine not good for?

Answer 28

chronic pain

Question 29

describe tramadol

Answer 29

* Weak opioid effect plus inhibitor of serotonin and noradrenaline reuptake * Less respiratory depression * Can be used with opioids and simple analgesics * Controlled drug * N+V

Question 30

describe morphine

Answer 30

``` • Cheap, generally safe • Oral, IV, IM, SC • Effective if given regularly • Good for o Mod-severe active nociceptive pain e.g. post-op o Chronic cancer pain • Constipation • Respiratory depression in high dose • Misunderstandings about addiction – possibility but if taking for pain and stop then unlikely to be an issue • Controlled drug • Oral dose is 2-3 times IV/IM/SC dose ```

Question 31

what class of drug is amitriptyline?

Answer 31

TCA

Question 32

what does amitriptyline do?

Answer 32

increases descending inhibitory signals

Question 33

what kind of pain is amitriptyline good for?

Answer 33

neuropathic pain

Question 34

apart from pain what does amitriptyline also treat?

Answer 34

depression | poor sleep

Question 35

side effects of amitriptyline

Answer 35

Anti-cholinergic glucoma urinary retention

Question 36

Give examples of anticonvulsant drugs used for pain

Answer 36

``` o Carbamazepine (tegretol) o Sodium valproate (Epilim) o Gabapentin (Neurontin) ```

Question 37

what do anticonvulsant drugs do in regards to pain?

Answer 37

reduce abnormal firing of nerves

Question 38

what kind of pain are anticonvulsant drugs good for?

Answer 38

neuropathic

Question 39

how can pain be assessed?

Answer 39

* Verbal rating score * Numerical rating score – doesn’t really equate to anything * Visual analogue scale * Smiling faces * Abbey pain scale (for confused patients)

Question 40

physical non drug treatments for pain

Answer 40

RICE surgery acupuncture, massage, physiotherapy positioning

Question 41

psychological non drug treatments for pain

Answer 41

explanation reassurance counselling

Question 42

describe the WHO pain ladder

Answer 42

see notes

Question 43

describe the RAT approach to pain management

Answer 43

``` • Recognise o Ask o Look (frowning, moving easily, sweating) o Do other people know the patient has pain: health workers, family • Assess o Severity § Pain score at rest and moving § How is it affecting the patient – move, cough, work o Type § Acute vs chronic § Cancer vs non-cancer § Nociceptive vs neuropathic o Other factors § Physical factors (other illnesses) § Psychological and social factors • Anger, anxiety, depression • Lack of social supports • Treat o Non-drugs § RICE § Nursing care § Surgery, acupuncture, massage, TENS etc § Psychological – explanation and reassurance, input from social worker/pastor o Drugs ```