Maintenance of Total Intravenous Anaesthesia in Donkeys Using Continuous Infusion with Detomidine and Ketamine

Abstract

The objective of the current study was to evaluate the anaesthetic properties, cardio-pulmonary and some biochemical effects following induction of anaesthesia in donkeys using different combinations of detomidine/ketamine. Six donkeys, 3-5 years of age with average body weight of 90�15 kg, were used in the study. Each animal was anaesthetized with one of two different protocols with two weeks interval between each two successive anaesthetic protocols injection as washing out period. In the first protocol, donkeys were premedicated with 50?g/kg detomidine intravenously (IV) and then after 10 minutes donkeys were injected with 4mg/kg ketamine intravenously (IV) for induction of anaesthesia (DK). In the second protocol, anaesthesia was induced as mentioned above and then maintained immediately by intravenous infusion of 6mg/kg ketamine and 50?g/kg detomidine in saline drip (DKI). Physiological parameters: respiratory rate, heart rate and rectal temperature were monitored before, during and following induction of anaesthesia. Induction quality, muscle relaxation, phases of anaesthesia and recovery time and quality were also studied. Some blood biochemical parameters: blood urea, plasma glucose concentration, ALT, and AST activity were measured before and during anaesthesia. Results obtained showed that, respiratory rate and rectal temperature were affected significantly (p? 0.05) as a result of using each of the two protocols. A significant difference (p? 0.05) was also observed regarding analgesia, lateral recumbancy, standing and walking time and total recovery time. Muscle relaxation quality ranged between good and poor. Induction quality was found to be smooth to fair in the two protocols. Recovery from DK anaesthesia was smooth to fair and from poor to very poor in case of DKI. Glucose and urea levels were significantly (p?0.05) affected in the two protocols used. It is to be concluded that although these protocols induced no cardio-respiratory or metabolic changes, the poor and very poor quality of recovery may limit the usefulness of the intravenous infusion maintenance of anaesthesia with DKI attempted in this study. However, considerable prolongation of anaesthesia was achieved