Effects of yohimbine, an alpha 2-antagonistic reversal agent, on physiological recovery parameters of anesthetized sows

Abstract

Objective: To evaluate the efficacy of yohimbine as an anesthetic reversal agent for sows anesthetized with a combination of xylazine, ketamine, and telazol. Materials and methods: Anesthesia was induced with xylazine, ketamine, and telazol in a single syringe, injected intramuscularly (IM). Following a 20-minute stabilization period, palpebral reflex was evaluated, and if absent, sows were injected IM with sterile saline (Control sows; n = 12) or yohimbine HCl (0.1 mg per kg; Yohimbine sows; n = 12). Data collected included insensibility measures (palpebral reflex, jaw tone, nose prick, alertness to human approach test, body posture) and physiologic measurements (heart rate, rectal temperature, respiratory rate, oxyhemoglobin saturation). Data was collected every 10 minutes until complete sensibility was attained. Results: Yohimbine sows recovered from anesthesia 162 minutes earlier than Control sows (P < .01). For all insensibility measures, Yohimbine sows regained a normal response more quickly than Control sows (P < .001). In addition, Yohimbine sows maintained greater heart rate (P < .05) and rectal temperature (P < .001) between onset of anesthesia (the time anesthetic agents were injected) to completion of the trial (when sow attained complete return to sensibility). Respiratory rate and oxyhemoglobin saturation were maintained within normal physiological ranges throughout anesthesia, confirming that respiratory capability was not compromised under this anesthetic protocol. Implications: Yohimbine is an effective reversal agent in sows anesthetized with xylazine, ketamine, and telazol administered simultaneously. This agent can be used by veterinarians to ensure a quicker recovery from anesthesia with minimal complications.