Physiological and clinical parameters under different protocols of total intravenous anesthesia in llama (Lama glama) undergoing unilateral ovariectomy

Abstract

Background: The limited and detailed literature on total intravenous anesthesia (TIVA), as well as the clinical indications for unilateral ovariectomy in llamas, are not well-defined. Therefore, it is necessary to understand the anesthetic events and the surgical intervention in this species.
Aim: The objective of this study was to evaluate the intraoperative physiological and clinical parameters in llamas undergoing unilateral ovariectomy, under three protocols of TIVA.
Methods: The study was conducted with 30 healthy female llamas. Three groups were considered G1: Pre-anaesthetic - xylazine i/v, Induction: ketamine. Maintenance: fentanyl and ketamine (FLK) (fentanyl + lidocaine + ketamine) by continuous infusion. G2: Pre-anaesthetic - midazolam + tramadol + ketamine i/v. Induction – propofol. Maintenance,
boluses of 20% of the total induction dose were added if required. G3: Pre-anaesthetic - midazolam + xylazine i/v. Induction: ketamine. Maintenance: with 20% of the total induction. Physiological parameters were evaluated at 5, 15, and 30 minutes.
Results: The heart rate, respiratory rate, arterial oxygen saturation (SpO2 ), and rectal temperature (RT) of the groups showed significant differences at some point in the evaluation, presenting a degree of bradycardia and bradypnea in G1 and G2. A drop in SpO2 was seen at minute 5 in all groups, because of respiratory depression post-anesthetic induction, subsequently, the values increased, with better saturation in G2. RT remained similar in the groups until minute 20, then there was a significant decrease in G2. G1 showed significant fluctuations for SpO2 and G2 for RT. The majority of animals from G1 and G3 maintained marked relaxation of the abdomen and limbs, anal sphincter (G3), and mandible (G1). Salivation and tearing were an infrequent sign in G2. All animals from G3 presented some degree of sensitivity to the abdominal wall. The average duration of the surgery was 14 minutes, and the shortest anesthetic recovery time occurred in G2 (28 minutes).
Conclusion: The animals of the three groups showed significant differences in their physiological and clinical parameters, in response to the agents used. The G1 protocol: xylazine, ketamine y FLK. Demonstrated better physiological and hemodynamic stability with an acceptable level of surgical anesthesia.