Limitations of these analgesics include, but are not limited to:
- The need for repeat oral or injectable administration (which places patients at risk for analgesic gaps and consumes valuable technician time).
- Concerns over untoward side effects (e.g., sedation, gastrointestinal upset) of varying severity, even at clinically recommended dosages.
The most effective means of preventing the transduction and transmission of pain is through the use of local anesthetics. Current methods of providing local anesthetics include wound/tissue infiltration, lidocaine strips, topical creams, regional nerve blocks, epidurals, and the placement of soaker catheters. Although the use of local anesthetics perioperatively is supported by the American Animal Hospital Association (AAHA)/American Association of Feline Practitioners (AAFP)3 and World Small Animal Veterinary Association (WSAVA) Pain Guidelines (https://www.wsava.org/Guidelines/Global-Pain-Council-Guidelines)4 there are limitations that function as barriers to their use.
These limitations include:
- Technical difficulty associated with some nerve and epidural blocks.
- Potential complications of the indwelling soaker catheter.
- Short duration of action (< 8 hours) of the available formulations of local anesthetics.
Please note charts are best viewed on a larger screen or desktop.
There are numerous local anesthetics with well-established safety and efficacy profiles available for clinical use in the perioperative period.4 Bupivacaine HCl was introduced into clinical practice in the early 1960s and is now one of the most commonly used and longest-acting local anesthetics, but its clinical benefit is limited by a duration of action that rarely exceeds 8 hours.5
3. Epstein ME, Rodonm I, Grllftnhogtn G, et al. 2015 AAHAIAAFP pain management guidelines for dogs and cots./ Fe/int Med Surg. 2015;17(3):251·272.
4. Mathews K, Kronen PW, Lascelles D, et al. Guidelines for recognition, assessment and treatment of pain. J Small Ani. 2014;55(6):E10-E68.
5. Lascelles BDX, Kirkby Shaw K. (2016), An extended release local anaesthetic: potential for future use in veterinary surgical patients? Vet Med Sci, 2:229-238. doi:10.1002/vms3.43