38 – Chronic Pain Flashcards
1
Q
What behaviour changes do associate with chronic pain?
A
- Aggression/reactivity
- Attention seeking
- Sleep pattern changes
- Loss of normal behaviours
- Change in navigation in environment
- Depression
- Licking/chewing/biting painful areas
- Anxiety and fear
- *PRESENTS IN MANY WAYS, AND OFTEN MISSED!
o Masked by STRESS
2
Q
What is chronic pain?
A
- Any pain lasting more than 3 months
- Slow onset
- Some acute pain stats can present chronically (ex. root tooth abscess)
- Avoidance behaviour masks pain ID
- Vet assessment is challenging
- Behaviour problems are a common sequela
3
Q
Pain and behaviour
A
- up to 82% of dog and cat behaviour cases have a PAIN component
- Ex. hip, stifle, dental, allergies
4
Q
Chronic pain prevalence in dogs and cats
A
- Dogs: 56% (NOT just an old age problem)
- Cats: ranges from 60% DJD, by 12 years old 90%
5
Q
Chronic pain and anxiety
A
- **chronic pain includes the MENTAL HEALTH of the animal
- Share behavioural responses due to sharing same neural pathways
o Ask yourself why? Is there a pain component? - Ex. allergies in people + dogs: chronic itch=chronic pain
6
Q
How should chronic pain be assessed?
A
- Physical exam: not great
- Clinic observation: not great
- Wound palpation
- **home videos and photos!
o Sleep: dogs need 14-16 hrs (cats need more)
o Poke animal on back if safe - Share infographic with owner
7
Q
What are the 3 types of chronic pain?
A
- Somatic inflammatory pain
- Visceral
- Neuropathic
*can occur concurrently
8
Q
C-fibers and pain
A
- Think chronic
- Unmyelinated: travels slower
- Pain perception:
o Dull, poorly localized, persistent
9
Q
A-delta fibers and pain
A
- Think acute
- Myelinated
- Pain perception:
o Sharp, well localized
10
Q
Chronic inflammatory pain (somatic) (ex. OA, burns, trauma, surgery)
A
- A-delta : C ratio = 1:2
- Dermal, articular or musculoskeletal
- *easier to localize (but not always)
- Inflammatory mediators (persistent inflammatory pain can lead to other types of pain, ex. neuropathic pain)
11
Q
How do you treat somatic pain?
A
- NSAIDs: mostly dealing with an inflammatory process
o Deal with PRIMARY problem - NGF monoclonal antibody (Solensia/Librela): osteoarthritis component
- Platelet rich plasma therapy: more expensive
- Ancillary treatments
o *need to think what we are going to do LONG TERM
o Mitigate some ongoing trauma (ex. ramps) - Nutraceuticals
- MULTIMODAL therapy chronically
- Allergy treatment
12
Q
Chronic visceral pain (ex. peritonitis, gastric ulceration, IBD, cancer)
A
- A-delta : C ratio = 1:10
- Visceral afferent fibers travel with PS nerves (Ex. vagus nerve)
o Large overlapping receptor fields
o *difficult to localize - Gnawing, squeezing, cramping
13
Q
How do you treat chronic visceral pain?
A
- Treat the inciting cause
- Dietary change may help (low CHO, high protein and fat)
o Lower fermentation that creates GAS
o Especially with food allergies - Omega-3 FAs
- Antispasmodic agents
- Opioid agonist-antagonists or partial agonists
- NSAIDs, TCAs, SSRIs
14
Q
Neuropathic pain (ex. cancer, chronic inflammatory diseases (OA), interstitial cystitis)
A
- Pain initiated or caused by primary lesion or dysfunction in peripheral or central NS
- Present in many conditions
- Difficult to diagnose in animals (go with ‘gut feeling’)
- Ex. phantom limb pain (shooting, burning, electric-like sensation, tingling, stabbing)
- *hyperalgesia and allodynia
15
Q
How do you treat neuropathic pain?
A
- Generally start with NSAID trial
o Add analgesic adjuvants (TCAs, serotonin-NE reuptake inhibitors, anti-convulsant, tramadol) - Opioids in some situations: partial effectiveness
- *multimodal approach more effective than single therapy
