Pain

Question 1

What are the benefits of treating pain?

Answer 1

Physical- improve sleep, better appetite
Psychological- reduce suffering, less depression and anxiety
For family- improve function as member of family, maintain employment
For society- reduced hospital stays so reduced cost, able to work

Question 2

What are the different ways in which pain can be classified?

Answer 2

Duration- acute, chronic or acute on chronic
Cause- cancer or non-cancer
Mechanism- nociceptive or neuropathic

Question 3

What is the difference between nociceptive and neuropathic pain?

Answer 3

Nociceptive- pain stimulus is directed into the pathway

Neuropathic- nerve damage

Question 4

What are the characteristics of nociceptive pain?

Answer 4

Obvious tissue injury or illness
Also called physiological or inflammatory pain
Protective function
Described as sharp ± a dull aspect and well localized

Question 5

What are the characteristics of neuropathic pain?

Answer 5

Nervous system damage or abnormality
Tissue injury may not be obvious
Does not have a protective function
Described as burning/shooting ± numbness/pins and needles. Not well localized

Question 6

What are the four main steps in pain physiology?

Answer 6

Periphery
Spinal cord
Brain
Modulation

Question 7

Describe the pain physiology processes in the periphery

Answer 7

Tissue injury
Release of chemicals- prostaglandins, substance P
Stimulation of nociceptors
Signal travels in Aδ or C nerve to spinal cord

Question 8

Describe the pain physiology processes in the spinal cord

Answer 8

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

Question 9

Describe the pain physiology processes in the brain

Answer 9

Thalamus is the second relay station
Connections to many parts of the brain (cortex, limbic system, brainstem)
Pain perception occurs in the cortex

Question 10

Describe the pain physiology processes in modulation

Answer 10

Descending pathway from brain to dorsal horn

Usually decreases pain signal

Question 11

What are some examples of causes of neuropathic pain?

Answer 11

Nerve trauma
Diabetic pain
Fibromyalgia
Chronic tension headache

Question 12

What pathological mechanisms can cause neuropathic pain?

Answer 12

Increased receptor numbers
Abnormal sensitisation of nerves (peripheral or central)
Chemical changes in the dorsal horn
Loss of normal inhibitory modulation

Question 13

What are the drugs commonly used for pain?

Answer 13

Simples analgesics- paracetamol, NSAIDs (ibuprofen, diclofenac)
Opioids- codeine, dihydrocodeine, morphine oxycodone
Tramadol (mixed opiate and 5HT/NA reuptake inhibitor)
Nefopam (NMDA receptor antagonist, 5HT/NA reuptake inhibitor)
Antidepressants
Anticonvulsants
Ketamine
Local anaesthetics
Topical agents

Question 14

What non-drug treatment can be used for pain originating from the periphery?

Answer 14

Rest
Ice
Compression
Elevation

Question 15

What non-drug treatment can be used for pain originating from the spinal cord?

Answer 15

Acupuncture
Massage
TENS

Question 16

What non-drug treatment can be used for pain originating from the brain?

Answer 16

Psychological

Question 17

What drug treatment can be used for pain originating from the periphery?

Answer 17

NSAIDs

Local anaesthetic

Question 18

What drug treatment can be used for pain originating from the spinal cord?

Answer 18

Local anaesthetic
Opioids
Ketamine

Question 19

What drug treatment can be used for pain originating from the brain?

Answer 19

Paracetamol
Opioids
Amitriptyline
Clonidine

Question 20

What are the advantages of paracetamol

Answer 20

Cheap
Safe
Can be given orally, rectally or IV
Good for mild pain in isolation or moderate to severe pain in conjunction with other drugs

Question 21

What are the disadvantages of paracetamol

Answer 21

Liver damage in overdose

Question 22

What are the advantages of NSAIDs

Answer 22

Cheap
Generally safe
Good for nociceptive pain

Question 23

What are the disadvantages of NSAIDs

Answer 23

GI bleeds
Nephrotoxic
Can cause bronchospasm in sensitive asthmatics

Question 24

What are the advantages of codeine

Answer 24

Cheap
Safe
Good for mild to moderate acute nociceptive pain

Question 25

What are the disadvantages of codeine

Answer 25

Constipation | Not good for chronic pain

Question 26

What are the advantages of tramadol

Answer 26

Less respiratory depression | Can be used with opioids and simple analgesics

Question 27

What are the disadvantages of tramadol

Answer 27

Nausea and vomiting | Withdrawal possible

Question 28

What are the advantages of morphine

Answer 28

``` Cheap Safe Can be given orally, IV, IM, SC Effective if given regularly Good for moderate to severe acute nociceptive pain or chronic cancer pain ```

Question 29

What are the disadvantages of morphine

Answer 29

Constipation Respiratory depression Misunderstandings about addiction Controlled drug

Question 30

What are the advantages of amitriptyline

Answer 30

Cheap Safe in low doses Good for neuropathic pain

Question 31

What are the disadvantages of amitriptyline

Answer 31

Anti-cholinergic side effects (glaucoma, urinary retention)

Question 32

What are the advantages of anticonvulsants

Answer 32

Good for neuropathic pain

Question 33

How do treatments of neuropathic and nociceptive pain differ?

Answer 33

Nociceptive pain management based on WHO pain ladder Neuropathic pain manegement based on alternative analgesics (amitriptyline, gabapentin, duloxetine) and/or psychological and non-drug treatments

Question 34

What are the steps in the RAT approach to pain?

Answer 34

Recognise Assess Treat

Question 35

What steps should be taking when recognising pain?

Answer 35

Does the patient have pain? (Ask, look (frowning, moving easily, sweating?)) Do other people know the patient has pain? (Other health workers, patient’s family)

Question 36

What steps should be taking when assessing pain?

Answer 36

``` Verbal Rating Score Numerical Rating Score Visual Analogue Scale Smiling faces Abbey Pain Scale (for confused patients) Functional Pain ``` Assess severity, type, characteristics and any other factors

Question 37

What levels of pain corresponds to which steps of the WHO pain ladder?

Answer 37

Mild to moderate pain- step 1 Moderate to severe pain- step 2 Severe pain- step 3

Question 38

What drugs are on each step of the WHO pain ladder?

Answer 38

Step 1- Non-opioids: aspirin, NSAIDs, paracetamol Step 2- Mild opioids (codeine) with or without non-opioids Step 3- Strong opioids (morphine) Step 1 should be kept in conjunction with either step 2 or 3 but no need to keep step 2 when moved up to step 3