Sessions

Heart rate variability (HRV) analysis provides insight into the function of the autonomic nervous system; however, these relationships remain underexplored in veterinary anesthesiology. Currently, no information is available regarding how epidural anesthesia in cattle affects the autonomic nervous system and, through this pathway, systemic physiological function. The present study investigated how epidural lidocaine anesthesia (4 mL of 2% solution) affects cardiac autonomic regulation compared to 4 mL of normal saline administered at the same site. Eight healthy lactating Holstein–Friesian cows were enrolled in a two-period crossover study. On the first experimental day, four cows received lidocaine while the other four received normal saline into the caudal epidural space. On the second experimental day,treatments were reversed. Interbeat intervals were recorded at baseline and for 240 minutes following epidural injection, and HRV parameters associated with cardiac autonomic activity (heart rate, RMSSD, HF, and LF/HF) were calculated. To evaluate the overall effects of the treatments, the area under the curve (AUC) for the first 240 minutes post-intervention as well as the recovery time to baseline values were used. The results revealed no differences between the lidocaine and saline groups regarding either the area under the curve or the recovery times to baseline values for any of the HRV parameters. These findings suggest that low-dose sacrococcygeal epidural anesthesia does not detectably influence cardiac autonomic regulation in dairy cows.