29 – Perioperative Pain Management in Small Animals Flashcards
What are 3 components/characteristics of an analgesic plan?
- Preventative
- Multimodal: maximize analgesia, minimize overall side effects
- Flexible
What are 6 parts that could be part of a multimodal analgesic plan?
- *Opioid
- *NSAID (unless contraindicated)
- *Incorporate a local anesthetic
- Decide If administration of alpha2 agonist would be beneficial
- Choose analgesic adjuncts (ketamine, lidocaine, gabapentin) if needed
- Use nonpharmacologic techniques to minimize pain
Lily is restless and circling in cage after OHE: what can you give her to reduce pain?
- Hydromorphone OR buprenorphine
- Don’t want to use a different NSAID and mix them
- Fentanyl infusion: overkill for this situation
- Butorphanol: not enough analgesia
Athena, 1 year old DSH post spay. Given dexmedetomidine, hydromorphone, propofol, isoflurane and then buprenorphine post-op. Still painful, so what can we do now?
- TOP up of buprenorphine and meloxicam (since no NSAID yet)
- Not hydromorphone as you used buprenorphine
- Not dexmedetomidine (alpha2 agonists) NOT for dogs and cats: CV side effects and sedation
What might the underlying causes of uncoordinated agitated activity and vocalizing be?
- Pain
- Emergence delirium
- Dysphoria
- Anxiety
If pain (uncoordinated agitated activity and vocalizing)
- Can be temporarily distracted
- Calmed by interaction, will resume behaviour when left alone
- Source of pain can be IDed
- Opioids improve the situation
If emergence delirium (uncoordinated agitated activity and vocalizing)
- Anesthesia related behaviour
- Attributed to residual inhalant anesthesia
- Only in immediate recovery period (after extubation)
- Self limiting: resolve within several minutes
- Sometimes requires sedation
If dysphoria (uncoordinated agitated activity and vocalizing)
- Reaction to ‘overdose’ of opioids
- Difficult to distract or calm by interaction
- Don’t respond to light palpation of painful area
How can you treat dysphoria?
- Sedation (low dose acepromazine, dexmedetomidine)
- Partial opioid reversal (careful titration)
o Butorphanol
o Naloxone
If anxiety (uncoordinated agitated activity and vocalizing)
- Can be temporarily distracted
- Calmed by interaction, will resume behaviour when left along
- NO source of pain can be IDed
- Animals responsive to TLC, sedation (trazadone, gabapentin)
- Limit time in hospital
Mu agonist opioids affects
- Analgesia: +++
- Sedation: +++
- Vomiting: ++
- Bradycardia: ++
- Respiratory depression ++
What are mu agonist opioids reversed with?
- Naloxone
o IV slowly, diluted to effect
o Short duration, narcotization
o Side effects: hypertension, tachycardia, CNS stimulation
Hydromorphone
- First line of pain control for moderate to severe pain
- One dose lasts 1-4hrs
- Dose-dependent side effects
What are the dose-depended side effects? (Hydro)
- Panting: dogs
- Nausea, vomiting
- Dysphoria, hyperthermia: cats
- Respiratory depression, bradycardia
- Urine retention, GI-ileus
Buprenorphine
- Partial mu-agonist
- Popular for cats
- Preferred route of administration: IV, IM
- Avoid oral transmucosal and SC
- Slow onset time
- Duration: 4-6 hrs
- *Rarely causes vomiting or dysphoria
- Euphoria in cats
- Ideal for MILD to MODERATE pain
When should you avoid using buprenorphine?
- If planning to use a pure mu-agonist in NEAR future
Butorphanol
- Kappa agonist
- Can reverse with mu-opiod agonist (dilute, slow to effect)
- 30-90min duration
- WEAK analgesic
- MILD sedative
- Potent antitussive
- Does NOT cause panting in dogs
Opioids: continuous rate infusions advantages
- Provides consistent levels of analgesia
- Adverse side effects are minimized
- Less drug used overall
What are the 3 doses/ways to give Fentanyl?
- Low dose in awake patients
- High does intraoperatively
- Bolus
Fentanyl
- POTENT analgesic
- Sedative
- Respiratory depression
Cat was 8-10/20 score, has a high respiratory and going for surgery within next couple hours. What can you give? (blackberry)
- Butorphanol: NOT enough
- Hydromorphone: GOOD choice
- Buprenorphine: don’t use then stuck with using it
- Ketamine: great as an addition, but not first drug you reach for (less for ACUTE PAIN)
- Meloxicam: good choice: but would want to know before (hydration and liver and kidney values normal?)
- *reach for a mu-opioid
Gave hydromorphone, but pain score did not change much. Now what? (blackberry)
- If give more=worry about side effects
- *Fentanyl continuous rate infusion (CRI)
What is your anesthetic plan for premedication? (blackberry, on Fentanyl already)
- Fentanyl
- Midazolam
What is your anesthetic plan for induction?
- Alfaxalone to effect
- Co-induction with Ketamine
What is your anesthetic plan for maintenance?
- Isoflurane
- Fentanyl
- Ketamine
What is your anesthetic plan for post-operative analgesia?
- Fentanyl
- Ketamine
- Meloxicam (now have the blood levels back)
