Assessment and Comparison of Three Selected Total Intravenous Anaesthetic Infusion Combinations in Donkeys

Abstract

The purpose of this study was to report on the quantitative and qualitative aspects of intravenous anaesthesia induced using Ketamine hydrochloride (K) combined with three different 2-adrenoceptor agonists viz: Xylazine (X), Detomidine (D) and Romifidine (R) with or without intravenous infusion with the same combination, in donkeys for use under field conditions. In the first part of the study, three different combinations of Ketamine were evaluated as follow: in the first combination 6 donkeys were either anaesthetised with Xylazine (2mg/kg)/ Ketamine (4mg/kg) (XK) or anaesthesia was induced with XK and maintained with intravenous Xylazine (2mg/kg)/Ketamine (6mg/kg) infusion (XKI). Another 12 donkeys were used in the same way in the second and third combinations using Detomidine (50µ/kg) and Romifidine (100µ/kg) instead of Xylazine as in the above mentioned manner i.e. DK and DKI, and RK and RKI, with two weeks interval between each successive injection as washing out period. Physiological parameters: namely respiratory rate, heart rate and rectal temperature were monitored before, during and following induction of anaesthesia. Anaesthetic effects: induction quality, muscle relaxation, phases of anaesthesia and recovery time and recovery quality were also studied. Some selected blood biochemical parameters: namely urea, glucose, alanine aminotransferase (ALT), and aspartate aminotransferase (AST) were measured before and during anaesthesia. In the second part of the study the three evaluated protocols (XKI, DKI, and RKI) were used to anaesthetize donkeys to perform laparotomy. The same parameters as in the first part of the study were evaluated in the experimental animals following induction and maintenance of anaesthesia and performing laparotomy. Results obtained indicated that in the first part where Xylazine and Ketamine were used for anaesthesia, the two protocols XK and XKI resulted in smooth to fair quality of anaesthesia. In case of induction and maintenance of anaesthesia with XKI the duration of muscle relaxation was found to be more than 40 minutes, where XK caused muscle relaxation for 20 minutes only. Recovery from anaesthesia with either XK or XKI ranged between smooth, fair and poor quality. Very poor recovery was not observed to occur as a result of using each of the two protocols i.e. XK or XKI. Induction and maintenance of anaesthesia with XKI resulted in a duration of analgesia phase, lateral recumbancy phase and total recovery time which were found to be significantly longer (p≤0.05) than the same phases resulted from using XK. Respiratory rate and rectal temperature were found to be decreased for different durations as a result of using either XK or XKI .Heart rate was found to be non significantly affected as a result of using XK or XKI. Induction and maintenance of anaesthesia with XKI lead to a significant elevation in blood urea level. Blood glucose level was significantly increased (p≤0.05) as a result of using either XK or XKI for anaesthesia. Induction quality ranged between smooth to fair quality as a result of using DK or DKI for induction or induction and maintenance of anaesthesia. Induction and maintenance of anaesthesia with DKI caused the muscle to be relaxed for different degrees for more than 40 minutes while induction of anaesthesia with DK resulted in relaxed muscles for 20 minutes only. Smooth and fair recovery was noticed to occur in case of induction of anaesthesia using DK, while induction and maintenance of anaesthesia with DKI resulted in either poor or very poor recovery. Respiratory rate and rectal temperature were observed to be (p≤0.05) significantly decreased for different durations of time as a result of using either DK or DKI. Heart rate was found to be non significantly affected as result of using either DK or DKI. Induction and maintenance of anaesthesia with DKI caused a significant increase (p≤0.05 ) in urea level, while DK was found to have non-significant effects on blood urea concentration. Blood glucose was found to be significantly elevated (p≤0.05) for different durations as a result of using DK or DKI for induction or induction and maintenance of anaesthesia.ALT and AST were found to be non significantly changed as a result of using DK or DKI. Using RK or RKI for induction or induction and maintenance of anaesthesia resulted in an induction quality which found to be ranged between smooth to fair induction. Muscle relaxation resulted from induction of anaesthesia with RK was found to occur for 20 minutes while muscle relaxation resulted from RKI was found to last for more than 40 minutes. Smooth and fair recovery were recorded to occur as result of using RK for induction of anaesthesia, while recovery from induction and maintenance of anaesthesia with RKI was found to be ranged between smooth, fair and poor recovery. Analgesia phase, lateral recumbancy phase, sternal recumbancey phase, standing and walking time together with the total recovery time were found to be significantly different in case of using RK compared to RKI. Respiratory rate and rectal temperature were found to be significantly depressed as a result of using either RK or RKI. Heart rate was found to be non significantly affected either in case of induction or induction and maintenance of anaesthesia using RK or RKI respectively. A significant elevation in blood urea level for different durations was found to occur as a result of using RK or RKI induction and induction and maintenance of anaesthesia respectively. Glucose level, ALT and AST showed non-significant changes as a result of using either RK or RKI for induction or induction and maintenance of anaesthesia respectively. In the second part of the study anaesthesia was induced and maintained with Xylazine / Ketamine / Infusion (XKIS), Detomidine/Ketamine/Infusion (DKIS) and Rominfidine/Ketamine/infusion (RKIS) to perform surgery. Induction of anaesthesia was found to be ranged between smooth and fair in the whole group of animals subjected to anaesthesia with XKIS, DKIS and RKIS. The abdominal muscle relaxation was found to be ranged between excellent and satisfactory for about 40 minutes as a result of using either XKIS, DKIS or RKIS. Recovery quality was found to be ranged between smooth and fair in animals anaesthetized with XKIS. When animals subjected to anaesthesia with DKIS recovery quality was found to be ranged between fair and poor quality. All animals anaesthetized with RKIS showed smooth recovery. Respiratory rate and rectal temperature were significantly decreased (p≤0.05) as a result of using either of XKIS, DKIS or RKIS. Heart rate was non significantly affected as a result of using XKIS, DKIS or RKIS. Significant increase (p≤0.05 ) in blood urea and blood glucose observed to occur as a result of using XKIS, DKIS or RKIS for different durations from induction to full recovery.AST and ALT levels were not significantly affected as a result of using XKIS, DKIS or RKIS for induction and maintenance of anaesthesia to perform surgery. It is concluded that the three selected anaesthetic protocols used in this study proved to be reliable and safe for performance of laparotomy in donkeys and non of the animals used in the was died as a result of using of any of the protocols under investigation.