6 – Pain Measurement

Question 1

Physiological indicators of pain

Answer 1

• Related to activation of SNS
• Increased HR, RR, BP, T, pupil dilation
• Increased biomarkers: beta-endorphin
  *unreliable and not specific to pain (influenced by other factors: anxiety, stress, fear)

Question 2

Pain indicators

Answer 2

• Behaviour
• Posture
• Facial expression

Question 3

Practical subject approach: observing patient

Answer 3

• Without interaction
  o Orientation in cage, posture, activity level, facial expression, attitude
• While interacting
• Response to palpation of painful site

Question 4

Interacting with patient

Answer 4

• Call by name
• Stroke along back from head to tail
• Appropriate response?
• Tense?
• Anxious?
• Indifferent?

Question 5

Response to palpation of painful area

Answer 5

• No reaction to touch, but vocalizes/tenses with pressure
• Looking at area
• Withdraws
• Defensive by protecting area
• Withdraws fast, vocalizes, bites
• Freezing, gets rigid

Question 6

Challenges of pain assessment in animals

Answer 6

• Use of proxy (ex. DVM or owner: not the animal itself)
• Variant in pain response: age, species, individual
• Environmental or situational stressors (may mask pain)
• Different types of pain (ex. acute vs. chronic)

Question 7

Fearful vs. painful animals

Answer 7

• Fearful will probably still look at you

Question 8

Developing a pain assessment tool

Answer 8

• User friendly
• Score linked to an INTERVENTION level
• Valid
• Reliable
• Responsive

Question 9

Use of pain assessment tool?

Answer 9

• Increases objectivity and accuracy
• Improve consistency of pain recognition
• Assess response to treatment
• Ensure pain is PRIORITIZED
• Quantify pain
  *NEED AN OUTCOME MEASURE

Question 10

Preventive (pre-emptive) scoring system

Answer 10

• Score assigned according to level of pain that they are BELIEVED to experience
  o none, mild, moderate, severe
• not useful to treat individual patient
• simple to use
• allows preventative analgesic planning

Question 11

Anticipated levels of pain: mild

Answer 11

• early, resolving simple conditions

Question 12

Anticipated levels of pain: mild to moderate

Answer 12

• castration
• minor dental procedures

Question 13

Anticipated levels of pain: moderate

Answer 13

• urethral obstruction
• C-section

Question 14

Anticipated levels of pain: moderate to severe

Answer 14

• Osteoarthritis
• Peritonitis
• Ureteral, urethral obstruction

Question 15

Anticipated levels of pain: severe to excruciating

Answer 15

• Multiple factors
• Limp amputation
• Necrotizing pancreatitis

Question 16

Subjective or unidimensional scales: examples

Answer 16

• Simple descriptive scale (SDS)
• Numerical rating scale (NRS)
• Visual analog scale (VAS)
• Dynamic interactive visual analog scale (DIVAS)
  *don’t recommend using them

Question 17

Simple descriptive scale

Answer 17

• Most basic, easy to use
• Not validated
• 4-6 descriptors
• Scales are non-linear
• Descriptive words are open to different interpretations
• Extremely subjective
• Lack sensitivity to detect small changes in pain

Question 18

Numerical rating scale

Answer 18

• Similar to SDS
• Implies equal differences or weighting between each category
• ‘discontinuous scale’

Question 19

Visual analog scale

Answer 19

Visual analog scale
* Horizontal line representing pain experience
* 0: no pain, 10: worst pain possible
* Extensively used in humans (completed by patient)
* Vetmed: significant interobserver variability

Question 20

Dynamic and interactive visual analog scale (DIVA)

Answer 20

• Improvement of VAS
• Includes dynamic and interactive assessment of patients
  o Observe from distance, interact, palpation

Question 21

Multidimensional scales

Answer 21

*recommend using
* Categorized numerical rating scales
* Multi-dimension composite pain scales

Question 22

Categorized numerical rating scales

Answer 22

• Observe and interact
• Different categories where certain behaviours are chosen and assigned a value
• Sum of category scores=pain score
• Species and situation specific

Question 23

UMPS (University of Melbourne Pain Scale)

Answer 23

• Clinical use
• Multiple descriptors in 6 categories
• Total score of 27
• Not validated, labour intensive
• Requires baseline data

Question 24

Colorado state university canine acute pain scale

Answer 24

• Teaching tool
• Dogs and cats after trauma or surgery
• 3 categories are assessed and assigned a score 0-4
• Observation and hands on
• Practical, user friendly
• NOT validated

Question 25

Multi-dimension composite pain scales

Answer 25

* Glasgow composite measures pain scale * UNESP: MCPS

Question 26

Glasgow composite measure pain scale (CMPS)

Answer 26

* First validated canine acute pain scale * 7 behavioural categories with 47 descriptors * Too time consuming * Useful research tool, not feasible in clinical environment

Question 27

CMPS: short form

Answer 27

* Highly practical, clear repeatable * Acute pain * Behavioural assessment * Reduced interobserver validity * Validated * Intervention score * *6 behavioural categories

Question 28

UNESP- Botucatus Multidimensional Composite Pain Scale (MCPS)

Answer 28

* Validated for cats undergoing OHE * 4 broad categories o Psychomotor changes o Protection of wound area o Physiologic variable o Vocal expression of pain * Score 0-30

Question 29

Cow pain score

Answer 29

* 7 behaviours evaluated * Intervention score=5/14

Question 30

Facial expression scoring system: grimace scale

Answer 30

* Identify and assess severity of pain * Rabbits, horses, sheep, pigs * Easy to use * Often incorporated in multidimensional pain measures or standalone

Question 31

Facial action units

Answer 31

* Orbital tightening * Ear position * Cheek bulge * Nose bulge * Whisker position

Question 32

Horse grimace score

Answer 32

* Composite, simple descriptive scale * 6 facial parameters with well-defined categories * Good reliability and validity * Other emotional states don’t change score significantly * Easy and give to use * Not validated against independent data set

Question 33

Chronic pain assessment

Answer 33

* Use owner as proxy * Ex. Helsinki chronic pain index (HCPI) * Ex. canine brief pain index * Liverpool osteoarthritis in dogs * Feline musculoskeletal pain index * Client specific outcome measures

Question 34

Clinical measurement instruments for chronic pain: evaluate behaviours in normal setting

Answer 34

* Going up and down stairs * Eating * Grooming * Ability to jump in car * Difficulty in rising * Inappropriate urination or defecation *useful to assess effect of treatment

Question 35

Canine Brief Pain Inventor

Answer 35

* Chronic pain: osteoarthritis, bone cancer * Record owners assessment * Assess pain severity and how pain interferes with daily life/function

Question 36

Feline musculoskeletal pain index: measures impact of osteoarthritis on domains of:

Answer 36

* Pain * Mobility * Activity * Affective effects

Question 37

Client specific outcome measures -felines (CSOMf)

Answer 37

* Choose 3 behaviours that the cat doesn’t do well anymore or has stopped doing * Easier as there is only 3 behaviours for them to have to assess

Question 38

Gait analysis: force plate, pressure mat walkways

Answer 38

* Objective methodology to evaluate limb motion * Research and referral facilities * Not practical in everyday * Difficult to interpret in presence of multiple arthritic joints * Helpful in detection of changes in lameness but not stiffness

Question 39

Accelerometers: activity monitors

Answer 39

* Objective, non-invasive, portable * Able to evaluate active movement at home