230 Pain

Question 1

What is the definition of chronic pain?

Answer 1

Pain which persists longer than normal healing times

Question 2

What are the 4 components of the IMMPACT guidelines for chronic pain?

Answer 2

1. Pain intensity
2. Physical function
3. Emotional function
4. Participant rating of improvement

Question 3

Which hereditary condition is due to mutations in the voltage gates Na channels?

Answer 3

Congenital insensitivity to pain

Question 4

What is the TRPV-1 receptor?

Answer 4

Capsaicin receptor which is activated with heat or cold

Pain when >43 degrees

Question 5

What are A-delta fibres?

Answer 5

Myelinated nociceptors - quick, unimodal

Question 6

What are C-fibres?

Answer 6

Unmyelinated nociceptors

Question 7

What are A-beta fibres?

Answer 7

Nerves which detect pressure and tactile sensation - can inhibit nociception

Question 8

Name 3 endogenous opioids

Answer 8

Endorphins
Enkephalins
Dynorphins

Question 9

Through which part of the spinal cord do 1st order spinothalamic neurones ascend 1-2 levels in the spinal cord before decussating?

Answer 9

Lissauer’s fasciculus

Question 10

Where in the grey matter do 1st order neurones synapse with 2nd order neurones in the spinothalamic tract?

Answer 10

Substantia gelatinosa

Question 11

Name 3 parts of the brainstem which receive fibres from the spinothalamic tract

Answer 11

Periaqueductal grey
Locus coeruleus
Raphe nucleus

Question 12

What do the descending tracts from the brainstem stimulate spinal interneurones to release in the feedback system?

Answer 12

Enkephalins

Question 13

What 2 things do the enkephalins released from the spinal interneurones cause to ‘dampen down’ pain APs?

Answer 13

1. Inhibits NT release from the presynaptic neurone

2. Hyperpolarises the post-synaptic membrane

Question 14

Which opioid receptors do endorphins have the highest affinity for?

Answer 14

Miu

Question 15

Which opioid receptors do enkephalins have the highest affinity for?

Answer 15

Delta

Question 16

Which opioid receptors do dynorphins have the highest affinity for?

Answer 16

Kappa

Question 17

Which inflammatory factors activate/sensitise nociceptors during inflammation?
(4 listed)

Answer 17

ATP
PGs
Bradykinin
Histamine

Question 18

What is the action of substance P in nociception?

Answer 18

Stimulates release of histamine

Dilates blood vessels

Question 19

What is primary hyperalgesia?

Answer 19

Increased pain sensitivity immediately following tissue injury

Question 20

What is the treatment for trigeminal neuralgia?

Answer 20

Carbamazepine

Question 21

Which NSAID has the lowest thrombotic risk?

Answer 21

Naproxen

Question 22

Name 2 weak opioids

3 listed

Answer 22

Codeine
Dihydrocodeine
Tramadol

Question 23

What is the treatment for opioid O/D?

Answer 23

Naloxone

Question 24

Name 3 strong opioids

5 listed

Answer 24

Fentanyl
Morphine
Oxycodone
Methadone
Pethidine

Question 25

Which strong opioid is strongest against kappa and delta opioid receptors?

Answer 25

Oxycodone

Question 26

Name 2 common opioid S/E | 5 listed

Answer 26

``` N&V Drowsiness Unsteadiness Delerium Constipation ```

Question 27

What is the MOA of ketamine?

Answer 27

NMDA receptor antagonist

Question 28

What is the intensive theory of pain?

Answer 28

Pain = emotional state caused by intense stimuli

Question 29

What is Descartes theory of pain?

Answer 29

Single wire theory - pain has its own apparatus independent of other senses

Question 30

What is the gate theory of pain?

Answer 30

Pain is not just related to extent of tissue damage - can have things which 'open' and 'close' pain gate.

Question 31

Name 2 things which open the 'pain gate' | 5 listed

Answer 31

``` Negative thoughts Pain watching Anxiety and panic Sedentary lifestyle Fear of pain ```

Question 32

Name 2 things which close the 'pain gate' | 5 listed

Answer 32

``` Distraction Happiness and laughter Relaxation and calm Excercise Reassurance ```

Question 33

What is dolorimetry?

Answer 33

Measuring pain threshold

Question 34

What is the MOA of tramadol?

Answer 34

Inhibits reuptake of NA | Stimulates serotonin release

Question 35

What are celecoxib and etoricoxib?

Answer 35

COX2 inhibitors

Question 36

What is the precursor for COX enzymes?

Answer 36

Arachidonic acid

Question 37

What does COX 1 stimulate? | 3 listed

Answer 37

Thromboxane A2 for platelet aggregation PGs in upper GIT - gastroprotective PGs in kidneys - renal perfusion

Question 38

What is the peak-end rule?

Answer 38

Theory that the last pain you felt of e.g. a procedure in the one you remember despite the intensity of the pain prior to the end pain.