Cardiopulmonary and gastrointestinal motility effects of xylazine/ketamine-induced anesthesia in horses previously treated with glycopyrrolate.

The research explores the influence of the drug glycopyrrolate on maintaining heart function in horses undergoing anesthesia with xylazine and ketamine. The study found that the use of glycopyrrolate before administering anesthesia resulted in improved heart function and higher oxygen levels in the horses, even though intestinal movement was still inhibited during the anesthesia period.

Methodology

Six healthy horses were used in the study. The horses were first given either a saline solution or a dosage of glycopyrrolate, based on their body weight. Fifteen minutes later, they were administered the anesthetic mix of xylazine and ketamine. After anesthetization, the horses were given oxygen and maintained by an infusion of both xylazine and ketamine.

• Various health indicators such as mean arterial pressures, central venous pressures, heart rate, cardiac index, and arterial and mixed venous blood gas tensions were monitored for up to 40 minutes after inducing anesthesia.
• Intestinal motility was also observed by auscultating four abdomen quadrants for 24 hours post-anesthesia induction.

The collected data were then analyzed using multiple statistical methods suitable for analyzing continuous and non-parametric variables.

Results

The observations showed:

• Horses given glycopyrrolate demonstrated significantly improved health parameters such as heart rate, mean arterial blood pressures, cardiac index, oxygen delivery and mixed venous oxygen tensions.
• Horses also showed less tissue oxygen extraction in comparison to those treated with a saline solution.
• Despite the improvements, it was observed that both groups of horses (those given glycopyrrolate and those given only saline) still exhibited a complete loss of intestinal motility, a common side effect of general anesthesia.

Conclusions

The research concluded that the use of glycopyrrolate significantly reduced cardiovascular dysfunction caused by general anesthesia using xylazine and ketamine in horses. Despite this positive effect however, the return of intestinal motility was delayed by 3 to 6 hours in both groups, indicating that glycopyrrolate treatment had no noticeable effects on improving this common side effect. Overall, the use of glycopyrrolate prior to anesthesia administration didn’t cause any severe side effects and can potentially improve the cardiovascular stability of horses during anesthesia.