Romifidine as a constant rate infusion in isoflurane anaesthetized horses: a clinical study.

The research article discusses a clinical trial aimed at evaluating the effects of a constant rate of romifidine infusion on the necessity for isoflurane, cardiac performance and the recovery process of horses under anaesthesia for arthroscopic surgery.

Research Procedure

• The research conducted was a randomized, blinded prospective clinical trial in which thirty horses due for routine arthroscopy were used.
• The horses were pre-medicated with acepromazine, romifidine, and methadone before being inducted with midazolam and ketamine.
• Anesthesia was then maintained with isoflurane in oxygen. The horses were then randomly assigned to two groups: a romifidine constant rate infusion (CRI) group (R) and a saline CRI group (S).
• An analysis of variance was used to evaluate the effects of treatment and time on anaesthetic and cardiovascular parameters. Additionally, the weight of the body, duration of anesthesia, and recovery score were compared across the two groups.

Research Findings

• All horses, except for one, were oriented in a dorsal recumbent position and ventilated from the start of anaesthesia.
• There was no significant change in the concentration of end-tidal isoflurane over the duration of anaesthesia in both treatment groups.
• The cardiac output was lower in group R (romifidine). However, there was no significant difference in cardiac index, body weight, or age between groups R and S.
• All other cardiovascular parameters remained similar across the groups.
• The quality of recovery was not different across the groups. However, horses in group R displayed better recovery with more horses standing without ataxia on first attempt.
• One horse from group S demonstrated a problematic recovery.

Conclusion

• There were no observable effects in terms of side effects or inhalation of anesthetic sparing by using a 40 microg kg(-1) hour(-1) romifidine CRI in isoflurane anaesthetized horses under these conditions.
• Despite the reduced cardiac output in the romifidine group, cardiovascular performance was deemed acceptable.
• The study concludes that additional research is necessary to determine the effective dose of romifidine that will cause an inhalation anesthetic sparing effect in anaesthetized horses.