Prolonged anesthesia using sevoflurane, remifentanil and dexmedetomidine in a horse.

The study revolves around the successful use of sevoflurane, dexmedetomidine, and remifentanil for prolonged anesthesia in a horse that underwent a partial mandibulectomy.

Research Objectives and Methods

• The primary objective of the study was to evaluate the efficacy of a specific combination of anesthetic drugs, namely sevoflurane, dexmedetomidine, and remifentanil, in performing a prolonged and invasive surgical procedure on an Arabian mare.
• The 10-year old mare was found to have a slow-growing mass on its lower right mandible and required a major operation- a large partial mandibulectomy.
• Following initial assessment and pre-operational procedures, anesthesia was induced using xylazine, ketamine, and diazepam. There were no detectable abnormalities apart from the mass.
• For maintaining anesthesia during surgery, researchers used an infusion of sevoflurane, dexmedetomidine, and remifentanil, with the surgical procedure extending for 13 hours. A temporary tracheostomy was performed to aid in delivering ventilation to the horse through a cuffed tracheotomy tube.

Monitoring, Post-operative Management, and Recovery

• The research team closely monitored parameters such as heart and respiratory rates, ECG, arterial pressures, inspired and expired gases, pulse oximetry values, and body temperature during surgery to ensure the horse’s stability.
• Dobutamine and whole blood were found to be necessary, and romifidine was used to control the recovery process. To provide post-operative pain relief, a regiment of phenylbutazone and buprenorphine given systemically along with bupivacaine administered through wound soaker catheter were utilized.
• The mare exhibited head-shaking as a side effect to the buprenorphine treatment, which was controlled with an intervention of acepromazine and detomidine. This was observed only after the mare started standing post-recovery period of 87 minutes.
• In the following days, the horse’s pain was managed with butorphanol, phenylbutazone, and bupivacaine, with this analgesic regimen lasting for three days post-surgery.
• The mare demonstrated good recovery, as she appeared comfortable and started feeding the very next day with no indication of ileus. The mare was found to be doing well seven months post-operation.

Research Conclusion

• This research concluded that a combination of sevoflurane, dexmedetomidine, and remifentanil infusions proved to be suitable for performing long and invasive procedures. The method was found to be effective and ensured a smooth recovery in this particular case study involving a horse.