Comparison of two injectable anesthetic combinations used to perform midline laparotomy for embryo recovery in Colombian creole ewes

Abstract

In the countryside, the use of halogenated anesthetics is difficult, therefore the use of injectable agents is an essential tool in anesthetic practice. This study aimed to compare two multimodal injectable anesthesia protocols and to determine the appropriate protocol to perform a medial laparotomy and embryo recovery in sheep. 16 healthy adult creole sheep were used. Animals were randomized to receive xylazine 0.2 mg/kg PC IM and ketamine 10 mg/kg PC IV (XK group), or a continuous infusion of 5% solution of xylazine (50 mg), ketamine (500 mg), and guaifenesin (500 mL) at a rate of 2.2 mL/kg/h IV (XKG group). Heart and respiratory frequency, rumen motility, and body temperature were evaluated before anesthesia, after induction, and during recovery. Induction was assessed by muscle spasms, nystagmus, and limb movement. Anesthesia was evaluated based on time, mandibular relaxation, skin sensitivity, and reflexes. Recovery was evaluated on a scale for anesthetic agent (0-10). Cardiorespiratory parameters decreased below baseline after induction of anesthesia in both groups. Between the groups, there was a significant difference in decubitus time (XK: 9.06 ± 0.73 min XKG: 7.81 ± 0.53 min) and recovery (XK: 53.13 ± 5.3 min XKG: 98.38 ± 5.71 min). Changes in the cardiopulmonary system were similar in both anesthetic regimens, and they were within acceptable clinical range. It is concluded that, in short surgical procedures, xylazine-ketamine anesthesia provides rapid induction, maintenance of physiological parameters within optimum limits, and rapid recovery.