Evaluation of Sevoflurane Anesthesia in Donkeys (Equus asinus) Premedicated With Xylazine and Induced With Thiopental.

Abstract

Sevoflurane is a volatile anesthetic agent that has become popular in the field of large animal anesthesia. The aim of this study was to evaluate the use of sevoflurane in adult healthy donkeys. Six male, adult, healthy donkeys were premedicated with xylazine (1\xa0mg/kg IV), induced with thiopental (5\xa0mg/kg IV), and then maintained for 90\xa0minutes with sevoflurane in 100% oxygen at a flow rate of 6\xa0L/min with spontaneous breathing. Rectal temperature (RT), respiratory rate, heart rate (HR), oxygen hemoglobin saturation (OHS), and mean arterial blood pressure (MBP) were measured before and 20\xa0minutes after the administration of xylazine, 10\xa0minutes after the injection of thiopental, and then continuously every 10\xa0minutes until recovery. Times for various signs of recovery, total duration of recovery, and quality of recovery were recorded. Jugular blood samples were collected from each donkey and complete blood counts and venous blood gases including concentrations of oxygen (PO2) and carbon dioxide (PCO2) were measured. In addition, the concentrations of sodium, potassium, calcium, lactate, bicarbonate, and glucose in venous blood were measured. Results showed that during the anesthesia maintained with sevoflurane, there was a significant decrease in HR, MBP, RT, red blood corpuscles, hematocrit, total white blood cells, neutrophils, and lymphocytes, whereas the levels of OHS and glucose significantly increased. The concentrations of PO2, PCO2, and lactate in venous blood significantly increased, whereas the pH significantly decreased. The levels of calcium significantly decreased immediately following the recovery. Sternal recumbency and standing occurred 15.8 ± 2.6\xa0minutes and 28.2 ± 2.2\xa0minutes, respectively, after turning off the vaporizer. Overall, the quality of recovery was good and relatively quick. It was concluded that sevoflurane appears to provide safe and effective anesthesia in donkeys, with relatively rapid induction and recovery.