Pain Management In Veterinary Medicine Flashcards
What is the definition of pain?
“ PAIN is an unpleasant sensory and emotional experience associated with, or
resembling that associated with, actual or potential tissue damage
What is transduction?
Conversion of a noxious stimuli to an action potential at the level of the nociceptors
What is projection?
Nociceptive info transported into the brain
What is perception?
Brain’s process of integrating the nociceptive info or the conscious processing of pain
How would you classify acute pain?
- Results of trauma, surgical or infectious events
- Starts abruptly, resolves in days/weeks
- Self-limiting, biological purpose
How would you classify chronic pain?
- Persists beyond normal time of healing/absence of healing
- > 1-3 months in duration
- Disease
What is somatic pain?
Well localised, aching, sharp, intense
* Superficial or Deep
What is visceral pain?
- Dull, diffused, poorly defined sensation
- Referred pain
What is neuropathic pain?
Caused by injury of the somatosensory system (i.e., peripheral nerves, spinal cord or brain)
What is allodynia?
Pain sensation in response to a non painful stimulus
What is hyperalgesia?
Exagerated pain sensation in response to a normally painful stimulus
What is the facial pain scale?
Observation of the subject from a distance
* Different action units
* No direct interaction
* Developed in many species
Why should we treat pain?
Avoiding
* stress reactions
* Delayed wound healing
* Inflammation
* Decreased appetite
What is pre-emptive analgesia?
Administration of analgesics drugs BEFORE the onset of the noxious stimulus
* Reason to administer analgesic drugs in premedication
What is multi-modal analgesia?
Use > than one pharmacological class of analgesic medications targeting different
receptors along the pain pathway
* Produce superior analgesia
* To reduce individual class-related side effects
What is tramadol?
Weak mu-receptor agonist
* Weak alpha 2 agonist action
* Inhibitor of norepinephrine & serotonin reuptake in the CNS
* NMDA receptor antagonism?
* Active metabolite minimal in dogs & cats after oral administration
* Analgesia?
* Serotonin Syndrome risk
* Vomiting, Drowsiness
What is an alpha-2 adrenergic receptor?
Analgesia shorter lasting compared to sedation?
* Spinal (pre & post synaptic) & Supraspinal * Adjunctives : synergistic with opioids * Acute Pain * Side effects: Sedation, Bradycardia & Blood pressure changes, emesis
What is ketamine?
Non- competitive NMDA receptor antagonist
* Interaction with many other
receptors (opioid, nicotinic &
muscarinic…)
* Acute & Chronic pain
What are the adverse effects of local anaesthetics?
Systemic toxicity (overdose, IV administration, species)
* Nerve & local tissue injury
* Local haemorrhage
* Infections
* Allergic reactions (preservatives, esters local anaesthetics)
What does lidocaine do?
Blockage of Na+ channels
* Anthiarrhythmic (class 1B)
* Anti-inflammatory
* Promotion of gut motility
* Nausea & Vomiting
What are the adverse effects of NSAIDS?
Vomiting, diarrhoea, anorexia, gastro-intestinal ulceration & perforation
* Renal injury
* Drug induced liver injury
* Coagulation
What is paracetamol?
COX-3 inhibition (brain): antipyretic effect
* Acute & Chronic Pain
* Weak analgesic & anti-inflammatory
* Licensed (dogs) with codeine for up to 5 days
* Analgesic mechanism of action?
* Prostaglandins inhibition
* Serotoninergic pathway activation
* Endocannabinoids enhancement
* L arginine/NO pathway
* Opioid Mu receptor agonist
What is the function of frunevetmab in cats/ bedinvetmab in dogs?
Inhibition of NGF mediated cell signalling to reduce pain
* Monthly subcutaneous injection
* Only licenced for treatment of PAIN associated with OA
* Contraindicated with NSAIDs (In humans)
* Allergic reaction, injection site reactions (dermatitis, alopecia, pruritus)
What do you use gabapentin in association with?
Neuropathic pain/ seizures
* Acute pain??
* Blockage of Ca2+ channels presynaptic neurons →↓ Ca2+ influx→ ↓ excitatory
neurotransmitters
* Use in association with NSAIDs, opioids…
* Side effects: Sedation, ataxia, vomiting, diarrhoea, increased appetite
What is amantadine?
Antagonist of N-methyl-D-aspartate (NMDA) receptors: blockage of pain
transmission
* Decrease central sensitization: long onset of action
* Chronic pain (in association with other analgesic drugs)
* Side effects: lethargy, gastro-intestinal upset, seizures
