Clinical anaesthesia in the horse: comparison of enflurane and halothane.

This study compares the effects of two anesthetic agents, enflurane and halothane, in horses. Researchers monitored a range of vital signs and metabolic parameters, and observed the conditions during surgery as well as recovery behaviour. The study concluded that while enflurane appeared safe, it induced significant respiratory depression and led to less smooth recovery, making it less desirable than halothane for equine anesthesia.

Objective and Methodology

• The research was conducted to compare the efficacy and safety of two anaesthetic agents – enflurane and halothane – for inducing and maintaining anesthesia in horses.
• Anaesthesia was initiated in 24 horses using xylazine and ketamine, and then maintained using either halothane (in 12 horses) or enflurane (in the other 12 horses).
• Several physiological parameters such as pulse rate, arterial blood pressure, arterial blood gas values, respiratory rate and tidal volume were recorded at regular intervals.
• Blood samples were taken regularly to assess levels of glucose, urea, haemoglobin, packed cell volume, gamma glutamyl transpeptidase, aspartate aminotransferase, alanine aminotransferase and creatine kinase.
• Researchers also monitored the conditions during operation and the horses’ behaviour during the recovery period.

Findings

• For horses in the enflurane group, researchers faced difficulties in maintaining a depth of anesthesia sufficient for surgery.
• This group also displayed a more significant depression of respiratory rate.
• No major differences were noted in arterial blood pressure values or in the hematological or biochemical parameters between the two groups.
• It was found that recovery from anaesthesia was noticeably faster in the horses given enflurane, but it was less smooth compared to the recovery of horses given halothane.

Conclusion

• Based on the study’s findings, researchers concluded that while enflurane seems to be safe for use in horses, it presents some challenges. The significant respiratory depression it caused, as well as the less smooth recovery process, make enflurane less desirable than halothane for equine anaesthesia.