Comparative efficacy of lidocaine and bupivacaine in epidural anesthesia in sheep

The issues of anesthesia during surgical operations in farm animals require the improvement and application of modern methods of both general and local anesthesia. The method of epidural anesthesia and the choice of the optimal anesthetic for its implementation are becoming increasingly widespread in veterinary practice, its dosage determines the adequacy of anesthesia. The present study was conducted in order to conduct a comparative assessment of clinical efficacy when using modern local anesthetics for epidural anesthesia of sheep. A series of 60 tests were conducted on sheep using 2% lidocaine hydrochloride (group I), 2% lidocaine hydrochloride with adrenaline (group II) and 0,5% bupivacaine hydrochloride (group III) at the Department of General, Private and Operative Surgery of St. Petersburg State University of Veterinary Medicine in the period from January to July in 2024. Each of the groups consisted of 20 healthy sheep aged from 1 to 2 years. The effect of anesthetics on heart rate, respiration, respiratory volume, minute ventilation and rectal temperature was monitored. During epidural anesthesia with 0.5% bupivacaine solution, there was a significant decrease in heart rate, a slight decrease in respiration and a decrease in rectal temperature. The heart rate and respiration rate increased significantly when using 2% lidocaine and when using 2% lidocaine with adrenaline. The use of adrenaline in the second experimental group allowed to increase the duration of action of 2% lidocaine. The duration of anesthesia with 0,5% bupivacaine in the third group was the longest in comparison with other groups. Drowsiness, tympania and trembling were observed in some cases when using 0,5% bupivacaine. It follows from the present study that the use of 2% lidocaine is most reasonably in epidural anesthesia in sheep.