Fiona, an 8-month-old, 22-lb (10-kg) spayed Labrador retriever, was presented for severe lameness of the left pelvic limb and anorexia one day after being hit by a car.
On examination, Fiona was depressed but responsive. Temperature was 100.4°F (38°C), heart rate was 130 bpm, and respiratory rate was 36 breaths/min. BCS was 5 of 9. Pain assessment with the short form of the Glasgow Composite Measure Pain Scale1 revealed a score of 8 of 24; scores greater than 6 of 24 indicate that interventional analgesia should be provided.1 Physical examination showed hematoma and marked edema in the region of the distal left femur. A fracture was noted on palpation. No other abnormalities were noted.
Hematocrit, total protein, and blood urea nitrogen values (obtained via dipstick) were 46%, 6 g/dL (60 g/L), and 5 to 15 mg/dL (1.78 to 5.36 mmol/L), respectively. Of note, if a patient remains hospitalized for more than 24 hours before fracture repair, hematocrit and total protein should be measured again on the day of surgery, as long bone fractures can be an important source of blood loss and consequent anemia. Abdominal-focused assessment with sonography for trauma (ie, aFAST) examination and thoracic radiographs disclosed no abnormalities. Pelvic radiographs showed a closed comminuted fracture of the distal left femur (Figure).
Treatment & Management
The analgesic protocol was developed according to the WSAVA Global Pain Council guidelines.2 Hydromorphone (0.1 mg/kg IM) was administered for pain relief and moderate sedation, which allowed for additional diagnostic testing and IV catheter placement in preparation for surgical correction of the fracture. Anesthesia and analgesia were provided using a multimodal approach. Preventive analgesia was achieved as part of premedication through IV administration of a second dose of hydromorphone (0.05 mg/kg) in combination with dexmedetomidine (1 µg/kg).
Opioids provide optimal analgesia for acute pain and are safe when administered at clinical dosages3; they should typically be included in acute pain management protocols.3 Dexmedetomidine provides sedation, muscle relaxation, and some degree of analgesia; decreases volatile anesthetic requirements; and is part of a balanced anesthetic protocol. Opioids and α2-adrenergic receptor agonists produce synergistic effects that result in optimal analgesia.2
Anesthesia was induced using alfaxalone at 1 mg/kg IV to effect and maintained with isoflurane at 1.25% inspired concentration in 100% oxygen using a rebreathing system. Lumbosacral epidural anesthesia was provided with preservative-free morphine (0.1 mg/kg) and bupivacaine (1 mg/kg).
Local anesthetics provide excellent volatile anesthetic-sparing effects, blunt stress response to surgery, and reduce analgesic requirements in the perioperative period.4 Morphine produces long-lasting analgesic effects (16-24 hours) when administered via epidural route.3 Administration of local or regional anesthesia eliminates the need for continuous infusion of opioids, α2-adrenergic receptor agonists, and ketamine and/or lidocaine.2
Anesthesia and surgery proceeded uneventfully with no hypotensive events. The fracture was stabilized using internal fixation. Carprofen (4 mg/kg SC) was administered immediately before extubation. NSAIDs such as carprofen provide excellent perioperative analgesia and should be used for orthopedic procedures unless contraindicated.2,5 NSAIDs can be administered during the intraoperative period if patients are healthy, fluid therapy is administered, and blood pressure is monitored.5
While Fiona recovered from anesthesia, the surgical site was treated with cold therapy using ice packing for 15 to 20 minutes. Cold therapy is an inexpensive, nonpharmacologic therapy that can reduce swelling and provide analgesia for postoperative pain, particularly following orthopedic surgery.2
Fiona remained hospitalized for 48 hours. A soft, padded bandage was applied to the left pelvic limb, and she rested in a comfortable bed in a clean, quiet environment. For the first 36 hours after surgery, she received carprofen (4 mg/kg SC q24h) and hydromorphone (0.05 mg/kg IV q6-8h) for analgesia based on pain scores assessed hourly using the Glasgow Composite Measure Pain Scale. Food and water were available ad libitum. Fiona was taken on short walks using a sling support and received cold compression therapy (10 minutes 6 times a day) along with gentle massage of the affected limb (5 minutes 6 times a day).
Patient needs should be evaluated based on clinical status and welfare, including pain assessment, general comfort, and anxiety level. Optimal pain management can be provided using pharmacologic and nonpharmacologic options.2 Nonpharmacologic modalities (eg, cold and hot compression therapy, massage, a warm bed, frequent walks on sling support) are important aspects of pain management following orthopedic surgery. As the patient begins to heal, additional therapies (eg, range-of-motion exercises) can be added and the frequency of other modalities decreased.
Approximately 36 hours after surgery, Fiona was bright, alert, and friendly. Pain was not elicited on palpation of the surgical site. She was discharged on gabapentin (10 mg/kg PO q12h for 4 days) and carprofen (4 mg/kg PO q24h for 7 days). Instructions were provided for cold and hot compression therapy (ie, cold compressions for 10 minutes 2-3 times a day for 1 week followed by hot compressions for 10 minutes 2-3 times a day for 4 weeks) and range-of-motion exercises (ie, 10 repetitions of flexion and extension 2-3 times a day).
Treatment at a Glance
- Preoperative: Hydromorphone (0.1 mg/kg IM); premedication with a combination of hydromorphone (0.05 mg/kg IV) and dexmedetomidine (1 µg/kg IV)
- Induction & Maintenance: Alfaxalone (1 mg/kg IV to effect); isoflurane 1.25% inspired concentration in 100% oxygen using a rebreathing system
- Intraoperative: Bupivacaine (1 mg/kg) and morphine (0.1 mg/kg) lumbosacral epidural; carprofen (4 mg/kg SC) administered immediately before extubation
- Immediate Postoperative (First 36 Hours): Hydromorphone (0.05 mg/kg IV q6-8h depending on pain evaluation), carprofen (4 mg/kg SC q24h), cold compressions (10 minutes q4h), massage (5 minutes q4h), a warm bed, and frequent walks on a sling support
- At Home: Gabapentin (10 mg/kg PO q12h for 4 days), carprofen (4 mg/kg PO q24h for 7 days), cold compressions (10 minutes q8-12h for 1 week) followed by hot compressions (10 minutes q8-12h for 4 weeks), and range-of-motion exercises (10 repetitions of flexion and extension q8-12h)
Prognosis & Outcome
Prognosis was good to excellent, provided the postoperative recommendations were strictly followed. At 8- and 16-week follow-up examinations, Fiona was recovering well. She was eating, drinking, urinating, and defecating normally. The owners were able to administer her medications and conduct the cold and hot compression therapy in the weeks following discharge.
Physical examination was unremarkable, and palpation of the fracture region elicited what appeared to be only mild discomfort. Moderate muscle atrophy was visible in the left thigh as compared with the right thigh. Radiographs of the left femur showed a well-aligned fracture that was healing appropriately. Instructions were given for a gradual return to physical activity over the following 6 to 8 weeks.
- Fractures cause moderate-to-severe pain. Aggressive perioperative analgesia should be provided using a multimodal preventive approach.
- The term preventive analgesia has replaced pre-emptive analgesia. Preventive analgesia encompasses all perioperative efforts to decrease postoperative pain and consumption of analgesic agents.
- Multimodal analgesia involves use of different classes of analgesic agents to achieve synergistic effects and decrease adverse events.
- Local and regional anesthetic techniques are cost-effective options for providing analgesia.
- Nonpharmacologic approaches complement use of analgesic agents in pain management.
- University of Glasgow. Anaesthesia and pain management. University of Glasgow Small Animal Hospital website. http://www.gla.ac.uk/schools/vet/sah/services/anaesthesiaandpainmanagement. Accessed June 13, 2017.
- Mathews K, Kronen PW, Lascelles D, et al. Guidelines for recognition, assessment and treatment of pain. J Small Anim Pract. 2014;55(6):E10-68.
- Simon BT, Steagall PV. The present and future of opioid analgesics in small animal practice. J Vet Pharmacol Ther. 2016. doi:10.1111/jvp.12377
- Kona-Boun JJ, Cuvelliez S, Troncy E. Evaluation of epidural administration of morphine or morphine and bupivacaine for postoperative analgesia after premedication with an opioid analgesic and orthopedic surgery in dogs. J Am Vet Med Assoc. 2006;229(7):1103-1112.
- Monteiro-Steagall BP, Steagall PV, Lascelles BD. Systematic review of nonsteroidal anti-inflammatory drug-induced adverse effects in dogs. J Vet Intern Med. 2013;27(5):1011-1019.
Paulo Steagall, MV, MSc, PhD, DACVAA
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.
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This article is published as part of the Global Edition of Clinician's Brief. Through partnership with the World Small Animal Veterinary Association, the Global Edition provides educational resources to practitioners around the world.