Evaluation of the antinociceptive effect of lidocaine- tramadol and lidocaine- medetomidine lumbosacral epidural anesthesia: A cross-over comparative study in goats

Abstract

Small ruminants have a docile temperament and are typically operated under local or regional analgesia. In goats, lumbosacral anesthesia is the most commonly used regional anesthesia. This investigation aimed to evaluate the epidural anesthetic effects of lidocaine-medetomidine (LID-MED) and lidocaine-tramadol (LID-TRM) combinations in relation to cardiopulmonary effects. An experiment using a cross-over design was conducted on eight goats. The first group (LID-MED) was injected with lidocaine hydrochloride and medetomidine hydrochloride. The second group (LID-TRM) was injected with lidocaine hydrochloride and tramadol hydrochloride. The onset of analgesia, recumbency time, and standing time were recorded once, while scores were recorded periodically. Locomotor and anti-nociception scores were evaluated at baseline, 5, 10, 15, 30, 60, 90, and 120 minutes (min) post-anesthesia. Similarly, cardiorespiratory values were also recorded at the same intervals in each group. In the LID-MED receiving group, analgesia and recumbency onset were earlier, with a longer recumbency period. The LID-MED group showed a significant loss of sensation in all examined regions. The locomotor score revealed hind limb paralysis for 90 min in the LID-TRM group, while it continued for 120 min in the LID-MED group. In both LID-TRM and LID-MED groups, there was significant hypothermia; however, bradycardia was noticed in the LID-MED group from 5 min post-injection. Respiratory depression was also detected in the LID-MED group. The study revealed that lumbosacral epidural anesthesia using LID-TRM co-infusion produces reasonable and short duration (60 min) analgesia. In contrast, epidural lumbosacral injection of LID-MED co-infusion produces a longer duration of analgesia and recumbency.