Pain Measurement & Assessment Flashcards
(43 cards)
What must you be able to do before you can treat pain?
you must be able to recognize it
What are physiologic indicators of pain?
- related to activation of the sympathetic nervous system
- increased HR, BP, temperature, pupil dilation
- increased biomarkers (B-endorphin, catecholamines, cortisol, chromagranin A)
- unreliable & not specific to pain
- influenced by other factors ex: anxiety, stress, fear, & drugs
- not always present in painful animals
What are the indicators of pain?
- behaviour
- posture
- facial expression
What is the practical subjective approach to observing pain?
- observing the patient w/o interaction (patient’s orientation in cage, posture, activity level, facial expression, attitude)
- observing the patient while interacting
- observing the patient’s response to palpation of painful site
What counts as interaction with a patient when assessing for pain?
- establish contact first (call by name)
- stroke along back from head to tail
- do they respond appropriately?
- are they painful if? (uninterested, indifferent, unresponsive; tense upon interaction; anxious, aggressive, trying to get away)
How might an animal respond to palpation of a painful area?
- no reaction to touching but vocalizes/tenses up w/ pressure
- looking at the area in question
- withdrawal
- defensive by protecting the area
- withdraws fast, vocalizes, bites
- freezing, gets rigid
How painful is this cat?
moderate pain
What are some basic challenges in pain assessment?
- pain is a dynamic, complex, multi-dimensional experience involving sensory and affective components
- uniquely personal experience
What are the challenges of pain assessment in animals in particular?
- use of proxy (DVM or owner; observer is assessing somebody’s subjective experience; respondent bias)
- variation in pain response (age, species (breed), individual)
- environmental or situational stressors (animal may mask pain - white coat effect)
- different types of pain (acute, chronic, etc.)
Is this cat fearful or painful?
- hunched, squinting, not looking at person in the post op picture
- fearful animals will still look at you & be curious of what is going on while painful ones may not
Why might someone use a pain assessment tool?
- increases objectivity & accuracy
- improves consistency of pain recognition
- assesses response to treatment
- ensures that pain is prioritized
- quantify pain
What does a pain assessment tool need?
NEEDS AN OUTCOME MEASURE!
Why should we be pain scoring our patients?
- imagine the treatment of your pain was in the hands of someone who neither speaks your language nor understands what it is to be human; you are at the mercy of that individual
- that well-meaning individual could undertreat you pain & leave you in agony or overtreat your pain leaving you groggy, dysphoric, nauseous, etc.
- assessment is the only way your caregiver can effectively & dynamically manage your comfort
What is important in a pain assessment tool?
- USER FRIENDLY (quick & easy, no lengthy training required
- score linked to an INTERVENTION TOOL
- VALID (measures what it is intended to measure)
- RELIABLE (produces the same score when an unchanging subject is measured at 2 time points by the same observer or by 2 observers at one time point (intra- & inter-rater reliability))
- RESPONSIVE (identifies clinically relevant changes (increase in pain/response to treatment))
What is a preventive (preemptive) scoring system?
- score is assigned according to level of pain that that animal is believed to experience
- categories: none, mild, moderate, or severe
- not useful to treat individual patient
- simple to use
- allows preventive analgesic planning
What are the anticipated levels of pain associated w/ various surgical procedures, illness, or injuries?
- mild pain (early, resolving, simple conditions)
- mild to moderate pain (castration, minor dental procedures, minor lacerations, cystitis, otitis)
- moderate pain (urethral obstruction, laparotomy, ovariohysterectomy, C-section)
- moderate to severe pain (osteoarthritis, acute polyarthritis, peritonitis, hollow organ distension, URETERAL or URETHRAL or BILIARY OBSTRUCTIONS, multiple dental extractions, thoracotomy)
- severe to excruciating pain (multiple fractures, limb amputation, necrotizing pancreatitis)
Which scales are subjective or unidimensional?
- simple descriptive scale (SDS)
- numerical rating scale (NRS)
- visual analog scale (VAS)
- dynamic interactive visual analog scale (DIVAS)
What is the simple descriptive scale?
- most basic & easy to use
- not validated
- four to six descriptors (no pain to worst pain)
- scales are nonlinear
- definitions of descriptive words are open to different interpretations
- extremely subjective & lack of sensitivity to detect small changes in pain
What is the numerical rating scale?
- similar to SDS
- implies equal difference or weighting between each category
- ‘discontinuous’ scale
What is the visual analogue scale?
- horizontal line (10 cm) representing pain experience
- 0 = no pain, 10 = worst possible pain
- segmental dividers or descriptors (bias?)
- is extensively used in human pain assessment & completed by patient
- vet med (significant interobserver variability (29-36%))
What is the Dynamic and Interactive Visual Analog Scale?
- improvement of the classic VAS
- includes dynamic and interactive assessments of patients (DIVAS 1: observation from a distance, DIVAS 2: interaction; DIVAS 3: palpation of injured area)
- score > 40mm = rescue analgesia
What are the types of multidimensional scales?
- categorized numerical rating scales (University of Melbourne Pain Scale (UMPS); Colorado State University Canine/Feline Acute Pain Scale; Canine Brief Pain Inventor (CBPI))
- multi-dimensional composite pain scales (Glasgow composite measures pain scale; UNESP - Botucatu multidimensional composite pain scale (MCPS))
What are categorized numerical rating scales?
- further development of simple descriptive and numerical rating systems
- observe & interact
- different categories where certain behaviours are chosen & assigned a value
- sum of category is pain score
- species specific
- situation specific
What is the University of Melbourne pain scale (UMPS)?
- designed for clinical use
- multiple descriptors in 6 categories
- based on specific behavioural & physiological responses (physiological data: HR, pupil size, & salivation; behavioural responses)
- total score of 27 (intervention score > 5)
- increased accuracy over VAS, SDS, or NRS
- not validated & labour intensive
- requires baseline data