Alfaxalone for maintenance of anaesthesia in ponies undergoing field castration: continuous infusion compared with intravenous boluses.

This research compares the use of alfaxalone, an anesthetic agent, delivered continuously through intravenous infusion or intermittently through injections for maintaining anesthesia in ponies undergoing field castration. The results suggest that both methods provide similar quality of anesthesia and surgical conditions. However, intermittent administration requires less alfaxalone.

Research Method

• The study involved 33 male Welsh ponies that were about to undergo field castration.
• Before anesthesia was induced, preanesthetic medication comprising of IV detomidine and butorphanol was administered. This medication aids in calming the ponies and easing them into the procedure.
• Anesthesia was induced with IV diazepam followed by alfaxalone which puts the ponies to sleep.
• The ponies were then randomly allocated into two groups. Anesthesia was maintained using IV alfaxalone in one group (Group A, n=16) while the other group was given saline equal in volume (Group S, n=17).
• When necessary, additional alfaxalone was administered intravenously to maintain anesthesia.
• Surgical condition and the recovery process from anesthesia were scored based on described scales.
• Data regarding the total amount of Alfaxalone administered, time duration from the induction to the end of infusion, and time to standing were recorded.

Study Results

• The overall quantity of alfaxalone used after inducing anesthesia and time to standing were higher in Group A compared to Group S.
• Four ponies in Group A required additional doses of alfaxalone compared to seven in Group S.
• Other variables being measured, including blood pressure, pulse, respiratory rate, end-expiratory carbon dioxide partial pressure, and blood oxygen levels, were similar in both the groups.
• Additional oxygen supplementation was necessary for five ponies, three from Group A, and two from Group S.

Conclusion

• The researchers concluded that the intermittent and continuous IV administration of alfaxalone delivered similar levels of anesthesia and surgical conditions in the ponies that underwent field castration.
• However, the intermittent administration required less alfaxalone which can be cost-effective and potentially safer as it reduces the risk of over dosage.