Combination of continuous intravenous infusion using a mixture of guaifenesin-ketamine-medetomidine and sevoflurane anesthesia in horses.

This research paper explores the effects of a hybrid anesthesia method in horses, which combines continuous intravenous infusion of guaifenesin-ketamine-medetomidine mixture with oxygen-sevoflurane. The study concludes that this combined method may be beneficial for long surgical procedures in horses due to its minimal cardiovascular impact and positive recovery outcomes.

Methodology

• The study examined 12 horses. The right carotid artery of each horse was surgically raised into a subcutaneous position.
• Two different anesthesia methods were used for the procedures. Six horses were anesthetized with the guaifenesin-ketamine-medetomidine and sevoflurane mixture, described as GKM-OS anesthesia. The other six were given regular oxygen-sevoflurane (OS) anesthesia.
• The researchers monitored the end-tidal concentration of sevoflurane (EtSEV) required to maintain surgical anesthesia. This was around 1.5% for GKM-OS and 3.0% for OS anesthesia.
• The mean arterial blood pressure (MABP) for each horse was also observed.

Results

• Under GKM-OS anesthesia, the MABP was maintained at around 80 mmHg. By contrast, the infusion of dobutamine was necessary to maintain MABP at 60 mmHg under OS anesthesia.
• Horses anesthetized with GKM-OS anesthesia were able to stand again 36 minutes after anesthesia cessation, on average, while those under OS anesthesia needed 48 minutes.
• Cardiovascular effects were also evaluated during both types of anesthesia. The study observed that GKM-OS anesthesia retained cardiac output and peripheral vascular resistance above 70% of the baseline pre-anesthesia value and maintained MABP over 70mmHg.
• For OS-anesthetized horses, an infusion of dobutamine was necessary to maintain MABP at 70mmHg. Though ensuring around an 80% cardiac output, it also led to severe tachycardia in one horse.

Conclusion

• The study concludes that GKM-OS anesthesia proved beneficial compared to traditional OS anesthesia due to its minimal cardiovascular effects and the good recovery post-anesthesia.
• Researchers suggest that GKM-OS anesthesia could be practical for prolonged equine surgeries because it does not substantially impact the cardiovascular system, and it allows for quicker recovery times.