Assessing analgesia equivalence and appetite following alfaxalone- or ketamine-based injectable anesthesia for feline castration as an example of enhanced recovery after surgery

Abstract

Objectives The primary study objective was to assess two injectable anesthetic protocols, given to facilitate castration surgery in cats, for equivalence in terms of postoperative analgesia. A secondary objective was to evaluate postoperative eating behavior. Methods Male cats presented to a local clinic were randomly assigned to receive either intramuscular ketamine (5 mg/kg, n = 26; KetHD) or alfaxalone (2 mg/kg, n = 24; AlfHD) in combination with dexmedetomidine (25 μg/kg) and hydromorphone (0.05 mg/kg). All cats received meloxicam (0.3 mg/kg SC) and intratesticular lidocaine (2 mg/kg). Species-specific pain and sedation scales were applied at baseline, 1, 2 and 4 h postoperatively. Time taken to achieve sternal recumbency and begin eating were also recorded postoperatively. Results Pain scale scores were low and showed equivalence between the treatment groups at all time points (1 h, P = 0.38, 95% confidence interval [CI] of the difference between group scores 0-0; 2 h, P = 0.71, 95% CI 0-0; 4 h, P = 0.97, 95% CI 0-0). Four cats crossed the threshold for rescue analgesia (KetHD, n = 1; AlfHD, n = 3). At 1 h, more cats in the KetHD (65%) group than in the AlfHD (42%) group were sedated, but statistical significance was not detected ( P = 0.15, 95% CI -1 to 0). Most AlfHD cats (88%) began eating by 1 h vs 65% of KetHD cats ( P = 0.039). Time to recover sternal recumbency did not differ between groups ( P = 0.86, 95% CI -14.1 to 11.8). Conclusions and relevance These results show that AlfHD and KetHD provide equivalent analgesia as part of a multimodal injectable anesthetic protocol. Alfaxalone is associated with an earlier return to eating.

A randomized clinical trial comparing butorphanol and buprenorphine within a multimodal analgesic protocol in cats undergoing orchiectomy

“…These include interference with the pain assessment scales used here, a longer and lower quality recovery, and a delayed return to eating. 18,19,26,28 The onset of action of buprenorphine is approxi mately 35 mins when administered IM based on results of thermal nociceptive threshold testing. 29 As this is longer than our time from injection to the start of sur gery, buprenorphine may not have reached its peak effect by the start of surgery.…”

“…Applying these principles has been highly effective for multiple procedures and populations in human medi cine, resulting in shorter hospital stays, reduced surgical site infections, improved comfort and reduced blood loss. [20][21][22][23] The application of ERAS in veterinary medicine is clearly in its infancy; 18,19 the successes achieved in human medicine warrant further investigation of the benefits for veterinary species.…”

“…An increasingly popular means of assessing perioperative care in human medicine, one that has been applied in cats, is enhanced recovery after surgery (ERAS). 18,19 ERAS is based on optimizing perioperative care and monitoring the impact of different strategies on multiple outcomes, such as pain relief and return to mobility and feeding. [20][21][22][23] Importantly, the desire for a rapid recovery and return to normal function should not be at the expense of analgesia.…”

“…Applying the principles of ERAS in cats has shown how anesthetic and analgesic protocol choice can shorten recovery to sternal recumbency and return to eating, while maintaining appropriate post operative analgesia. 18,19 The purpose of this study was to evaluate the effects of two IM anesthesia protocols employing multimodal analgesia on recovery and analgesia following orchiec tomy in cats. We hypothesized that the combination of buprenorphine-dexmedetomidine-alfaxalone with an intratesticular lidocaine block and postoperative meloxi cam would provide better postoperative analgesia than butorphanol (in place of buprenorphine).…”

“…Applying the principles of ERAS in cats has shown how anesthetic and analgesic protocol choice can shorten recovery to sternal recumbency and return to eating, while maintaining appropriate postoperative analgesia. 18,19…”