Cardiopulmonary and sedative effects of anaesthesia produced by climazolam in combination with medetomidine and fentanyl : an experimental study

In veterinary practice intraveneous anaesthesia has numerous advantages. An important advantage is the ease and rapidity of induction. Compared to administration of inhalant anaesthetics, a minimum of apparatus is necessary in administration of intraveneous anaesthetic agents. The possibility of antagonization of certain drugs used as intraveneous anaesthetics increases the safety of anaesthesia. The unpleasant recovery period can also be shortened, which for a busy veterinarian and also the owner can be of great relief. Ideally, a postoperative patient should be conscious, co-operative, calm and free of pain. This will provide better homeostasis of vital functions, allow early diagnosis and treatment of complications and decrease the need for nursing care. The aim of these studies was to analyze the sedative/ analgetic / anaesthetic, cardiovascular and respiratory effects produced by a combination of medetomidine and climazolam at two different dose levels (1.5 mg/kg and 3.0 mg/kg). Climazolam was also combined with fentanyl. Antagonization followed anaesthesia, using atipamezole, nalorphine and a new benzodiazepine antagonist, sarmazenil. 7 laboratory beagles were used inthis experimental study. In combination with medetomidine, climazolam produced smooth anaesthesia and had only small effects on the cardiovascular and respiratory system. Total analgesia was not achived. Intubation was easily performed. The antagonization proved to be fast and complete. When combining climazolam with fentanyl, dose levels were chosen according to previous studies (Erhardt et al., 1986). The anaesthesia was light and short, probably due to the short action of fentanyl. This combination depressed the respiratory system in a much larger scale than the combination of medetomidine and climazolam did. Antagonization was effective