Week 4 - pain management Flashcards
The pain response is unique to each individual and involves two components:
(1) the sensory component is nociception, which is the neural processing of noxious stimuli
(2) the affective component is pain perception, which is the unpleasant sensory and motional experience associated with either actual or potential tissue damage.
Acute pain vs chronic
Acute pain has been defined as pain that exists during the expected time of inflammation and healing after injury (up to 3 mo)
Chronic pain is defined as that which exists beyond the expected duration associated with acute pain
(pain that persists beyond the normal healing time or pain that persists in conditions where healing has not or will not occur)
The PLATTER Approach to Pain Management
PLan
Anticipate
TreaT
Evaluate
Return
Non-pharmacologic pain management examples (at least 3)
cold compression
acupuncture
physical rehabilitation/ therapy
therapeutic laser/ laser therapy
What is considered the ‘‘fourth vital sign,’’ after temperature, pulse, and respiration
a pain score
Chronic Pain: Characteristics
- Diminished exercise tolerance and general activity
- Difficulty standing, walking, taking stairs, jumping, or getting up
- Decreased grooming (cats especially)
- Changes in either urination or defecation habits
Chronic Pain -> Causes
Under-recognized and undermanaged chronic pain can result in premature euthanasia.
Proper recognition and management of chronic pain can be as life preserving as any other medical treatment in veterinary medicine
Butorphanol in dogs , what can be different about its analgesia?
In dogs, the l antagonist/ j agonist butorphanol in particular appears to have limited somatic analgesia and very short duration of visceral analgesia
Opioids should be used as a routine —– medicant ?
Opioids should be used as a routine preoperative medicant, preferentially in combination with a tranquilizer/sedative
buprenorphine is preferred over butorphanol in cats, why?
buprenorphine administered before surgery and during wound closure provided adequate analgesia for 6 hr following ovariohysterectomy in cats, whereas butorphanol did not
What is the preferred method for administering opioids in cats?
In cats, the subcutaneous route of opioid administration is not recommended.
IM and IV routes are preferred both pre- and postoperatively.
The oral transmucosal or buccal route of administration for buprenorphine may also have clinical efficacy as well
Opioids are what with a-2 adrenergic agonists?
Opioids are synergistic with a-2 adrenergic agonists
Opioids and patients undergoing major surgery..
- Periodic readministration of parenteral opioids.
- Constant or variable rate infusion. Calculators can be found online.
*Long-acting formulations and technologies (transdermal fentanyl product in dogs or concentrated injectable buprenorphine product for cats).
*Oral opioids (No comparable studies exist for cats).
NSAID - why use them
The majority of conditions that cause pain have an inflammatory component. Nonsteroidal anti-inflammatory drugs (NSAIDs) are a mainstay for management of chronic pain as well as for perioperative use
Non-approved NSAIDs (4)
aspirin,
ibuprofen,
naproxen
meloxicam for human use
Risks of Nonsteroidal Anti-Inflammatory Drugs
- gastrointestinal (GI) toxicity- vomiting, diarrhea, and inappetence
- erosions and ulcers
- nephrotoxicity - importance of maintaining a normotensive state during anesthesia
- hepatocellular necrosis
- delayed bone healing in rabbit and rodent
Nine Ways to Minimize the Risks of Nonsteroidal Anti-Inflammatory Drugs (NSAIDs)
- Obtain a complete medication history.
- Be discriminating in patient selection.
- Provide verbal and written client instructions
- Recognize the earliest signs of adverse events
- Perform laboratory monitoring.
- Utilize a balanced, integrated analgesic approach as part of NSAID-sparing strategies.
- Consider washout periods.
Based on pharmacokinetics, practitioners who wish to err on the side of caution may want to withhold meloxicam for 5 days and other NSAIDs or short-acting corticosteroids for 7 days prior to initiating treatment with another NSAID. - Use gastroprotectants
- Dose optimization.
Only class of drug that renders complete analgesia?
local anaesthetics (LAs)
a-2 Adrenergic Agonists …
a-2 Adrenergic receptors are located with opioid receptors.
Thus, the two drug classes used together are highly synergistic for sedation and analgesia
Ketamine …
- dissociative anesthetic
- Ketamine is particularly useful in veterinary practice for the following reasons:
- Anesthetic Induction
- Sedation and Restraint:
- Pain Management: Ketamine has analgesic properties, making it effective for controlling moderate to severe pain, especially in surgical or traumatic conditions.
Subanesthetic ketamine constant rate infusion (CRI) prevents pain and has antihyperalgesic, and antiallodynic effects
Systemic Lidocaine
- local and topical anaesthesia
Various formulations for a combination of orphine, lidocaine, and ketamine CRIs have been described in dogs
Tramadol …
- opiate analgesic
- use oral tramadol in a flavored compounded form (the drug is otherwise quite bitter)
Gabapentin
- is an anticonvulsant with analgesic properties
- Cats with Degenerative joint disease (DJD) and of chronic musculoskeletal pain
- Dogs with Degenerative joint disease (DJD)
- 8–12 hr dosing interval has been suggested
Adverse effect of Gabapentin in dogs?
somnolence
Bisphosphonates …
pain relief in dogs with bone cancer (IV infusion)
Corticosteroids …
- anti-inflammatory and immunosuppressive agents
- not primarily analgesic drugs,
- may exert a pain-modifying effect by reducing inflammation
Pain management for dogs and catsundergoing a surgical procedure include the following …(3)
- a preoperative opioid plus a tranquilliser / sedative
(eg. acepromazine & midazolam OR diazepam & dexmedotomidine) - Administration of NSAID either pre or postoperatively based on patient risk factors and clinician preference
- A LA
For patients undergoing procedures with risk, thefollowing interventions or drugs should be strongly considered (6)
- cold compression
- a-2 adrenergic agonist
- ketamine CRI
- lidocaine CRI
- gabapentin
- epidural anesthetic
Canine DJD: Therapeutic Considerations
weight loss
NSAID administration (Some dogs may require several weeks of NSAID treatment before clinical improvement is noted)
PSGAGs are more likely to have a beneficial effect when given early in the disease process (Polysulfated Glycosaminoglycans)
therapeutic exercise
Feline DJD: Therapeutic Considerations
Treatment of DJD in cats should focus on environmental modification in addition to pharmacologic therapy.
NSAIDs are the mainstay of pharmacologic treatment for DJD in other species, and there is considerable evidence to support their effectiveness in cats as well
(Low-dose meloxicam (i.e., 0.01–0.03 mg/kg per os q 24 hr) is effective in treating arthritic cats and is well-tolerated even in cats with chronic kidney disease (CKD) provided their clinical status is stable.)
