A pharmacodynamic study of propofol or propofol and ketamine infusions in ponies undergoing surgery.

This research investigates the effects of applying separate versus combined infusions of the drugs propofol and ketamine to ponies during surgery, with the main findings suggesting the combined administration results in superior maintenance of respiratory and cardiovascular functions and quicker post-anaesthesia recovery times.

Research Context and Objective

• The research was conducted in a veterinary surgical scenario, focusing on ponies undergoing castration surgery.
• The researchers’ goal was to compare the effect of infusions of the anaesthetic drugs propofol alone versus those of propofol combined with ketamine.

Experimental Approach

• The experimental sample was comprised of eight ponies, divided into two groups. Group 1 received infusions of propofol only during surgery, while Group 2 received combined infusions of propofol and ketamine.
• Regardless of their group allocation, all ponies were first put under anaesthesia using detomidine and a ketamine shot, with a propofol bolus dose following.
• The researchers administered the propofol infusion to Group 1 for an average of 74 minutes, and to Group 2 for an average of 60 minutes.

Results and Conclusions

• The infusion rates and types varied between groups: Group 1 received a mean propofol rate of 0.330 mg per kg per minute, whereas Group 2 had a mean propofol rate of 0.124 mg per kg and a consistent ketamine rate of 40 micrograms per kg per minute.
• Some ponies receiving propofol alone (Group 1) exhibited arterial hypotension and significant respiratory depression during surgery. In contrast, ponies given combined propofol and ketamine (Group 2) maintained their respiratory and cardiovascular functions better.
• The recovery post-anaesthesia was faster in Group 2, with average times to sternal recumbency and standing in minutes considerably shorter compared to Group 1.
• Overall, the study’s findings suggest that the combined administration of propofol and ketamine during pony surgery may be more beneficial in terms of anaesthetic control and recovery times compared to the use of propofol alone.