Université de Montréal, Saint-Hyacinthe, Quebec, Canada
From a global perspective, veterinarians routinely work with patients in severe pain (eg, from trauma, from orthopedic surgery). Treatment of acute pain is easier when opioids—the cornerstone of acute pain management—are available. But for many, they are not.
How can clinicians approach these cases in regions where narcotics are unavailable, as is the case in many countries in Latin America, Africa, Asia, and in some areas in North America and Europe? This is one of the biggest issues in animal welfare and pain management globally, and there is no simple answer.
The analgesic effects of local anesthetics, α2-adrenoreceptor agonists (eg, xylazine, medetomidine, dexmedetomidine) and NSAIDs as part of a multimodal approach for perioperative pain should not be underestimated.
In some countries where µ-opioid receptor agonists (eg, morphine, methadone, fentanyl) are not available, other opioids or opioid-like drugs (eg, tramadol, butorphanol, nalbuphine) may be available to be used as part of premedication and in combination with a local anesthetic block or NSAID.
For example, in the case of the dog undergoing orthopedic surgery, the patient could have been premedicated with injectable tramadol and xylazine or medetomidine; received an epidural with lidocaine or bupivacaine; and given an injectable or oral NSAID dose.
Tramadol may have limited analgesic effects in dogs, but it can be used for injectable and inhalant anesthetic-sparing effects while reducing anxiety (when given with a sedative) in the hospital setting. The drug is available in injectable form in some countries. The effects of tramadol on opioid receptors and serotonin and noradrenaline reuptake inhibition may provide some clinical analgesia, particularly in cats.
Butorphanol and nalbuphine are agonist–antagonist of opioid receptors. These drugs are not ideal for treatment of severe pain and should not be used for this purpose; however, they can be given as part of premedication, especially if locoregional anesthesia is used. Indeed, local anesthetics provide excellent intraoperative and early postoperative analgesia and muscle relaxation and decrease injectable and inhalant anesthetic requirements. Locoregional anesthetic techniques (eg, epidural, brachial plexus, sciatic, femoral nerve blocks) should always be employed, as they completely replace the use of opioids in the intraoperative period, provided the block is effective Anesthetic recovery is usually calm and rapid, as long as the patient is not painful.
Several NSAIDs are approved for use in dogs and cats in many countries. NSAIDs provide anti-inflammatory, analgesic, and antipyretic effects and should be used when contraindications (eg, dehydration, hypovolemia, kidney and hepatic disease, thrombocytopenia) have been excluded and when corticosteroids and/or other NSAID are not administered in close temporal association. These drugs are highly palatable and convenient for administration. In most cases, NSAIDs can be administered for several days as part of postoperative pain control.
Nonpharmacologic therapies (eg, bandaging, cold therapy, range of motion exercises, frequent walks on a sling, massage) can be used anywhere in the world and should always be part of a multimodal pain management approach.
One final thing that clinicians should never forget and can always help provide as veterinary professionals: TLC (tender, loving care). TLC, nutrition, a comfortable bed, and a clean, quiet environment are crucial ways to support patient wellness.