Evaluation of midazolam-ketamine-xylazine and propofol-ketamine combinations for maintenance of anaesthesia by constant rate infusion (CRI) in canine: haemato-biochemical study

Haemato-biochemical study was conducted to evaluate the constant rate infusion (CRI) anaesthesia using various protocols on 20 healthy bitches, aged less than 1 yr, and subjected to oophorectomy by conventional and laparoscopic methods. The animals were divided into 2 groups, which were further subdivided into 2 subgroups each containing 5 animals on the basis of anaesthesia used. All the animals received glycopyrrolate (0.01 mg/kg b.wt) and 10 min later xylazine (0.5 mg/kg b.wt) intramuscularly as preanaesthetic medication. After 10 min of the administration of preanaesthetics, induction of anaesthesia was achieved by administering midazolam (0.2 mg/kg b.wt) and ketamine (5.0 mg/kg b.wt) intravenously. After 5 minute of anaesthetic induction, the maintenance of anaesthesia was started with a combination of midazolam (0.4 mg/kg/hr)-ketamine (20 mg/kg/hr)-xylazine (1.0 mg/kg/hr) in animals of group A₁ and B₁, while propofol (3.6 mg/kg/hr)-ketamine (5.4 mg/kg/hr) in the animals of groups A₂ and B₂ as CRI with definite rate using an infusion pump. Haemato-biochemical evaluation of the anaesthetic protocols was done by estimating different parameters. To conclude, both midazolam-ketamine-xylazine and propofol-ketamine combinations did not cause severe haematobiochemical and electrolyte changes during CRI for maintenance of general anaesthesia.