Effect of administration of propofol and xylazine hydrochloride on recovery of horses after four hours of anesthesia with desflurane.

The research article presents a study that investigated the impact of propofol and xylazine hydrochloride on the recovery of horses after undergoing four hours of desflurane anesthesia. The study found that administration of these drugs delayed the horses’ awakening from anesthesia but improved the quality of their recovery.

Methodology

The researchers conducted their study on eight healthy horses with an average age of 6.6 years and an average body weight of 551 kg.

• Each horse was put under anesthesia twice using a combination of xylazine hydrochloride, diazepam, and ketamine hydrochloride. The anesthesia was then maintained for four hours using desflurane in oxygen.
• After each anesthetic episode, each horse randomly received an IV injection of either propofol and xylazine or a saline solution.
• The researchers took venous blood samples before and after anesthesia to measure serum creatine kinase activity and plasma propofol concentration.

Observations and Results

• As per the observations, the anesthetic induction and maintenance process occurred without incident in all horses.
• Compared to the administration of a saline solution, the post-anesthetic administration of propofol and xylazine resulted in a longer interval before the horses wake from anesthesia.
• However, horses that received this treatment exhibited an improved quality in their transition back to standing.
• Additional findings showed that compared to the saline solution, administration of propofol also delayed the decrease rate of end-tidal concentrations of desflurane and carbon dioxide in the horses.
• Administration of propofol was also associated with conditions promoting hypoxemia and hypoventilation, which can potentially harm the horses during the post-anesthetic period.

Conclusions

These observations led researchers to conclude that, while propofol and xylazine delivered IV after four hours of desflurane anesthesia improved the quality of horses’ transition from lateral recumbency to standing, they also increased the potential for harmful respiratory depression during the post-anesthetic period. This dilemma prompts for further studies to weigh the benefits against the potential risks.