Pain Assessment Flashcards
What is pain?
An upleasant sensory and emotional experience associated with, or resembling that associated with, actual or potential tissue damage
Individual experience
NOT THE SAME AS NOCICEPTION
Noxious Stimulus
A stimulus that is damaging or threatens damage to normal tissues
Nociception
The neural process of encoding noxious stimuli
Nociceptive Pain
Pain from activation of nociceptors
Central sensitisation
Increased responsiveness of nociceptive neurons in the central nervous system to their normal or subthreshold afferent input
Somatic Pain
Pain experienced from skin, muscle, bone damage/disease
Visceral pain
Pain experienced because of organ pain (abdominal or thoracic)
Neuropathic Pain
Pain caused by a lesion or disease of the somatosensory nervous system
In contrast to nociceptive pain
Wind-up
Wind-up is a frequency-dependent increase in the excitability of spinal cord neurones, evoked by electrical stimulation of afferent C-fibres
Adverse effects of unrelieved pain
Clinical Signs of Pain
○ Tachycardia
○ Tachypnoea
○ Hypertension or hypotension
○ Cardiac arrhythmias
○ Pale mucous membranes
○ Hypersalivation
○ Mydriasis (dilated pupils)
○ Sweating trembling
○ Poor body or coat condition
○ Changes in “stress hormones”
○ Cortisol, glucose, insulin, adrenaline, β-endorphins
○ Unreliable and non-specific
○ Increased by disease, fear, stress, handling, anaesthesia etc
How do prey species respond to pain?
Often don’t display pain behaviour
Survival response
What are the effects of unresolved pain on the neuroendocrine system?
- Hypoglycaemia
- Weight loss
*delayed wound healing - Impaired immune system
What are the effects of unresolved pain on the cardiovascular system?
Fatigue
Immobility
Weakness
What are the effects of unresolved pain on the respiratory system?
Decreased lung volume leading to atelectasis and hypoxaemia
What are the effects of unresolved pain on the GIT and urinary system?
Decreased bowel motility leading to constipation
(Ileus)
Anorexia
Urinary retention
What are the effects of unresolved pain on the MSK system?
Decreased muscle function and spasm leading to weakness
Immobility
Fatigue
What are the psychological effects of unresolved pain?
Anxiety
Poor sleep
How can you assess pain?
No ‘gold standard’
Use pain scales - multidimensional ideally
If in doubt, give analgesia and reassess
Example of a pain scale
Glasgow composite pain scale
Commonly used in dogs - also a cat version
Glasgow composite Pain Scale for dogs
Easy to use
Total score /24
Analgesia intervention if >6
Glasgow composite Pain Scale for cats
Includes pain faces
Total score /16
Signs of pain in a rodent
Ear Changes:
Fold, curl and angle forwards or outwards
Pointed shape
Orbital Tightening:
Narrowing of the orbital area
Partial or complete eye closure or squeezing
Nose/Cheek Flattening:
With eventual absence of the crease between the cheek and whisker pads
Whisker Change:
Move forward away from faceMove forward away from face
Signs of pain in horses
Asymmetrical/low ears or ears held stiffly backwards
Angled eye/tension above the eye area and orbital tightening
Withdrawn and tense stare
Nostrils – square-like/strained
Tension of the muzzle/strained mouth and pronounced chin
Tension of the mimic muscles/chewing muscles
Pain in Farm Animals
Very stoic
Prey animals
Don’t easily show signs of pain
Unwillingness to move is a predominant indicator
Chronic pain assessments
- Chronic pain is multifactorial and subjective
○ Mood
○ Posture
○ Movement domains- Chronic pain scales will be made up of questions from these domains
- Canine Brief Pain Inventory (CBPI) (OA & bone cancer pain)
- Liverpool osteoarthritis in Dogs (LOAD e)
- Feline Musculoskeletal Pain Index (FMPI)
- Client specific outcome measures (CSOM) dog and cat versions
