Week 4 - Prerequisite knowledge

Question 1

What is pain?

Answer 1

A sensory and emotional experience linked to actual or potential tissue damage

The person in pain is the authority on it—pain exists when and where they say it does.

Question 2

What are the four stages of how pain is generated and carried?

Answer 2

• Transduction
• Transmission
• Perception
• Modulation

These stages describe the process from tissue injury to the brain’s interpretation of pain.

Question 3

What happens during the transduction stage of pain?

Answer 3

Tissue injury releases chemicals (e.g., prostaglandins, bradykinin) that nociceptors convert into an electrical signal

This is the first stage in the pain pathway.

Question 4

What is the role of A-delta fibres in pain transmission?

Answer 4

Thinly myelinated, fast; sharp, localised pain; usually acute

They carry the initial sharp pain signal to the brain.

Question 5

What is the role of C fibres in pain transmission?

Answer 5

Unmyelinated, slow; dull, diffuse, persistent pain

They carry the longer-lasting, aching pain signal.

Question 6

What is the Gate Control Theory?

Answer 6

A dynamic ‘gate’ in the substantia gelatinosa regulates traffic from ascending pain fibres and descending brain signals

Touch input can close the gate, while strong nociceptive input opens it.

Question 7

What are the two main classifications of pain by time course?

Answer 7

• Acute pain
• Persistent (chronic) pain

Acute pain has a sudden onset, while persistent pain lasts beyond expected healing time.

Question 8

What is nociceptive pain?

Answer 8

Tissue pain via normal nociceptor processing

It can be somatic (skin/muscles/bones/joints) or visceral (organs).

Question 9

What is neuropathic pain?

Answer 9

Nerve injury/dysfunction; burning, tingling, electric-shock-like

It may respond poorly to opioids.

Question 10

What is catastrophising in the context of pain?

Answer 10

A cognitive style of magnifying threat and feeling helpless about pain

It is linked to worse outcomes and measured by the Pain Catastrophising Scale (PCS).

Question 11

What are some tools used to assess acute pain?

Answer 11

• NRS (0-10)
• VAS
• Verbal Rating Scale
• PQRST / OPQRSTUV

These tools help gauge pain intensity and characteristics.

Question 12

What is the Behavioural Pain Assessment Scale used for?

Answer 12

To rate face, restlessness, tone, vocalisation, consolability (0-10 total)

It is used when a person cannot self-report pain.

Question 13

What is the Functional Activity Score (FAS)?

Answer 13

A score that ties pain to function by asking the person to perform a relevant activity

It grades the activity from A (no limitation) to C (severe).

Question 14

What are some multidimensional tools for assessing persistent pain?

Answer 14

• Brief Pain Inventory (BPI)
• McGill Pain Questionnaire (MPQ/SF-MPQ)
• DN4 (neuropathic screening)
• PCS (catastrophising)
• PASS (pain anxiety)

These tools provide a broader understanding of pain beyond intensity.

Question 15

What is the bottom line for effective pain management?

Answer 15

Great pain management starts with great assessment: be holistic, suspend assumptions, and believe the patient’s report

This approach ensures a comprehensive understanding of the patient’s pain experience.

Question 16

What is McCaffery’s dictum regarding pain?

Answer 16

“Pain is whatever the experiencing person says it is, existing whenever they say it does.”

Guides validation and assessment.

Question 17

Define the difference between pain and nociception.

Answer 17

Nociception = neural processing of noxious stimuli; pain = conscious sensory + emotional experience (requires brain appraisal).

Understanding this distinction is crucial for pain management.

Question 18

What is the difference between protective and non-protective pain?

Answer 18

• Acute pain is typically protective (alerts to harm)
• Persistent pain often becomes non-protective and maladaptive

This distinction helps in understanding pain management strategies.

Question 19

Differentiate between afferent and efferent pathways.

Answer 19

• Afferent = ascending sensory input to CNS
• Efferent = descending motor/modulatory output from brain to spinal cord/periphery

These pathways are essential for understanding pain signaling.

Question 20

Name the key CNS structures involved in pain.

Answer 20

• Thalamus (relay/switch)
• Limbic system (affect/meaning)
• Reticular formation (arousal)
• Cortex (discrimination/attention)

Each structure plays a role in the perception and processing of pain.

Question 21

List the chemical mediators involved in transduction.

Answer 21

• Prostaglandins
• Bradykinin
• Histamine
• Serotonin
• Substance P
• H⁺/K⁺/Na⁺ flux → nociceptor depolarisation

These mediators are crucial for the initiation of pain signaling.

Question 22

Describe the clinical feel of A-δ vs C fibres.

Answer 22

• A-δ = sharp/pricking, well-localised
• C = dull/aching/burning, diffuse, lingering

Understanding these fibre types aids in pain assessment.

Question 23

What is the role of A-β fibres in pain gating?

Answer 23

Non-noxious touch/pressure fibres; stimulate inhibitory interneurons in dorsal horn → ‘rubbing it’ can reduce pain.

This mechanism is important for pain modulation.

Question 24

What is the dorsal horn substantia gelatinosa?

Answer 24

Site of ‘gate’ integration of small pain fibres, large touch fibres, and descending inhibitory signals.

This area is critical for the modulation of pain signals.

Question 25

Name the **descending inhibitory transmitters**.

Answer 25

* Endorphins/enkephalins (opioid receptors) * Serotonin * Noradrenaline ## Footnote These transmitters help dampen pain transmission in the spinal cord.

Question 26

Differentiate between **hyperalgesia** and **allodynia**.

Answer 26

* Hyperalgesia = increased pain to painful stimulus * Allodynia = pain to normally non-painful stimulus (often neuropathic) ## Footnote These conditions reflect different pain processing mechanisms.

Question 27

What is the difference between **peripheral** and **central sensitisation**?

Answer 27

* Peripheral: sensitised nociceptors at injury site * Central: spinal/brain neurons become hyperexcitable (‘wind-up’) ## Footnote Understanding these concepts is crucial for treating chronic pain.

Question 28

What role does **NMDA/glutamate** play in pain?

Answer 28

Noxious input releases glutamate → NMDA receptor activation contributes to central sensitisation and opioid resistance. ## Footnote This mechanism is significant in chronic pain conditions.

Question 29

Give examples of **somatic superficial** vs **deep pain**.

Answer 29

* Superficial: laceration, burn * Deep: muscle spasm, bone metastasis, post-op wound pain ## Footnote These examples illustrate the different types of somatic pain.

Question 30

What are the hallmarks of **visceral pain**?

Answer 30

* Poorly localised * Cramping/squeezing * Autonomic features (N/V/diaphoresis) * Referred pain * Cutaneous hyperalgesia ## Footnote Recognizing these features is important for diagnosis.

Question 31

Explain the **referred pain mechanism**.

Answer 31

Convergence of visceral and somatic afferents onto same spinal neurons → brain mislocalises source. ## Footnote This phenomenon complicates the diagnosis of pain.

Question 32

Define **cutaneous hyperalgesia**.

Answer 32

Increased skin sensitivity over an affected viscus (e.g., abdominal wall tenderness with visceral pathology). ## Footnote This condition is often seen in visceral pain syndromes.

Question 33

Describe the descriptors of **neuropathic pain**.

Answer 33

* Burning * Shooting * Electric shock * Pins/needles * Painful numbness * May have allodynia and hyperalgesia ## Footnote These descriptors help in identifying neuropathic pain.

Question 34

What are common **neuropathic aetiologies**?

Answer 34

* Post-stroke * MS * Spinal cord injury * Diabetic polyneuropathy * Nerve entrapment * Post-herpetic neuralgia ## Footnote These conditions are often associated with neuropathic pain.

Question 35

Describe the **cancer pain patterning**.

Answer 35

Often mixed mechanisms (nociceptive + neuropathic), persistent background with breakthrough episodes. ## Footnote Understanding this pattern is essential for effective pain management.

Question 36

What are the features of **breakthrough pain (BTP)**?

Answer 36

* Transient exacerbation despite controlled baseline * Rapid onset/short duration * Often needs rapid-onset rescue ## Footnote Recognizing BTP is crucial for effective pain management.

Question 37

Define **intractable pain**.

Answer 37

Severe, relentless pain not relieved by standard medical/surgical/nursing measures; major functional/psych impact. ## Footnote This type of pain poses significant challenges for treatment.

Question 38

What are the basics of **phantom limb pain**?

Answer 38

Pain perceived in a missing limb; neuropathic features; related to cortical reorganisation and ectopic activity. ## Footnote This phenomenon illustrates the complexity of pain perception.

Question 39

What is **somatoform (somatic symptom) pain**?

Answer 39

Pain with prominent psychological/behavioural maintenance; diagnosis of exclusion; avoid stigmatising language. ## Footnote This type of pain requires sensitive handling in clinical settings.

Question 40

How does **context/meaning** affect pain perception?

Answer 40

Threatening meaning increases pain; benign/valued meaning (e.g., labour) can reduce perceived intensity. ## Footnote This highlights the psychological aspects of pain.

Question 41

What are the effects of **attention/expectation** on pain?

Answer 41

* Hyper-attention and negative expectancy (nocebo) amplify pain * Positive expectancy (placebo) can reduce pain ## Footnote These effects are important in pain management strategies.

Question 42

List the **harmful effects of unrelieved pain** on the cardiovascular system.

Answer 42

* ↑HR * ↑BP * ↑cardiac workload * Hypercoagulability → ↑cardiovascular event risk ## Footnote Understanding these effects is crucial for comprehensive pain management.

Question 43

What are the **harmful effects of unrelieved pain** on the respiratory system?

Answer 43

* Shallow breathing * ↓lung volumes * Atelectasis * Secretion retention * Pneumonia risk * Impaired cough ## Footnote These effects highlight the importance of effective pain management.

Question 44

Describe the **harmful effects of unrelieved pain** on the endocrine/metabolic system.

Answer 44

* ↑Cortisol/catecholamines/ADH/RAAS → insulin resistance and hyperglycaemia * Catabolism ## Footnote These metabolic changes can complicate recovery.

Question 45

What are the **harmful effects of unrelieved pain** on the gastrointestinal/genitourinary systems?

Answer 45

* ↓Gastric emptying and motility → ileus/constipation * Urinary retention * Fluid/electrolyte issues ## Footnote These complications can lead to significant morbidity.

Question 46

List the **harmful effects of unrelieved pain** on the musculoskeletal & immune systems.

Answer 46

* Spasm * Immobility * Deconditioning * VTE risk * Stress-mediated immunosuppression and delayed healing ## Footnote These effects underscore the need for effective pain management.

Question 47

What are the **harmful effects of unrelieved pain** on neuropsychological aspects and quality of life?

Answer 47

* Anxiety * Sleep loss * Low mood * Hopelessness * Poorer recovery and participation ## Footnote These psychological impacts can hinder overall recovery.

Question 48

How do **acute** vs **persistent pain** differ in vital signs?

Answer 48

* Acute often shows sympathetic signs * Persistent pain often shows normal vitals due to parasympathetic balancing ## Footnote This difference is important for clinical assessment.

Question 49

What is included in the **minimum data set** for acute assessment?

Answer 49

* Location/character * NRS at rest & movement * Functional task (FAS) * Aggravating/relieving * Vitals * Plan & review time ## Footnote This data set is essential for effective pain management.

Question 50

What is the **rule of thumb** for reassessment timing?

Answer 50

* Oral analgesic: check 30–60 min * IV: 15–30 min * Regional: per protocol * Document time and effect ## Footnote Timely reassessment is crucial for effective pain management.

Question 51

How is the **Functional Activity Score (A/B/C)** used?

Answer 51

Test a relevant task (e.g., cough, sit-stand); A = no limitation, B = mild–moderate, C = severe; compare to baseline. ## Footnote This score helps in assessing functional impact of pain.

Question 52

What items are included in the **Behavioural Pain Assessment Scale**?

Answer 52

* Face * Restlessness * Muscle tone * Vocalisation * Consolability ## Footnote Each item is scored 0–2, with a total score of 0–10 to track pain interventions.

Question 53

What domains are assessed in the **Brief Pain Inventory (BPI)**?

Answer 53

* Severity now/worst/least/average (24 h) * Interference: general activity, walking, work, relations, mood, sleep, enjoyment ## Footnote This inventory helps in understanding pain impact on daily life.

Question 54

What is the value of the **McGill Pain Questionnaire (MPQ)**?

Answer 54

Profiles sensory/affective qualities and totals; useful when quality guides mechanism and targeting. ## Footnote This tool aids in comprehensive pain assessment.

Question 55

What are examples of **neuropathic screeners**?

Answer 55

* DN4 (≥4 suggests neuropathic) * Leeds Neuropathic Scale ## Footnote These screeners are used alongside history/exam for diagnosing neuropathic pain.

Question 56

What is the clinical impact of **catastrophising**?

Answer 56

Higher PCS predicts higher pain/disability and poorer treatment response; target with CBT/ACT and education. ## Footnote Addressing catastrophising is crucial for effective pain management.

Question 57

What does the **QUESTT framework** involve in pediatrics?

Answer 57

* Question child * Use scale * Evaluate behaviour/physiology * Secure parent input * Take cause into account * Take action/evaluate ## Footnote This framework ensures comprehensive assessment in children.

Question 58

What are the details of the **FLACC scale**?

Answer 58

Face, Legs, Activity, Cry, Consolability (0–2 each) for non-verbal/young children; max 10; repeat to track change. ## Footnote This scale is useful for assessing pain in non-verbal children.

Question 59

How should the **FACES scale** be used?

Answer 59

Explain faces show ‘how much you hurt right now’; child points to matching face; recommended for ≥3 years. ## Footnote This scale helps children express their pain levels.

Question 60

What caution should be taken regarding **paediatric physiology**?

Answer 60

Vitals/colour/sweat can reflect fear or sepsis; never use physiological signs in isolation—combine with behaviour/self-report. ## Footnote This approach ensures accurate assessment in children.

Question 61

What must be included in **documentation** for pain assessment?

Answer 61

* Tool used and scores (rest/movement/FAS) * Descriptors * Function impact * Interventions + times * Effect/side effects * Next review * Goals ## Footnote Comprehensive documentation is essential for continuity of care.