Multivariate analysis of factors associated with post-anesthetic times to standing in isoflurane-anesthetized horses: 381 cases.

This study investigates the variables related to anesthetic practices that may predict how quickly horses regain their ability to stand after being anesthetized with specific drugs. The research revealed that factors like the duration of anesthesia, hypothermia during surgery, and intraoperative hypotension could be managed to reduce recovery time, however, these factors accounted for less than 23% of the variation in recovery time, indicating the presence of other influential factors.

Research Methodology

• The research was conducted as a retrospective case series, reviewing 381 horse cases from the years 2000-2003.
• The selected horses were all older than 12 months and weighed at least 200 kg.
• The researchers only included horses in the analysis that were anesthetized with xylazine, ketamine, diazepam, and isoflurane.
• Data from the case records was thoroughly extracted and analyzed using multiple linear regression to determine the relationship between time to standing and various factors such as demographic information, intraoperative conditions, and anesthetic variables.

Research Findings

• Of the 381 horses, 326 (86%) were able to recover and stand unassisted, while 55 (14%) required assistance in recovery.
• The model to predict unassisted recovery time yielded a R(2) value of 0.228, showing a correlation between factors such as the presence of colic, anesthesia duration, lowest temperature during operation (temperature nadir), and duration of low blood pressure (hypotension).
• The model for predicting assisted recovery time yielded an R(2) value of 0.314, indicating a strong correlation with the horse’s emergency status, being of a warm-blooded breed, and the intraoperative administration of ketamine.

Conclusions

• The research suggested that anesthesiologists controlling factors like duration of anesthesia, hypothermia, and intraoperative hypotension could potentially reduce the recovery time of horses.
• Despite these findings, the contribution of these anesthesia-related factors explained less than 23% of the variability in recovery time, highlighting the need for further research into other potential factors that can influence anesthesia recovery time in horses.