The present work evaluated the anesthetic association of propofol, an ultra-short acting general anesthetic with a fast metabolism, with remifentanil, an opioid of great analgesic potency that is used as adjunct to general anesthetics. The main objective was to develop a safe protocol of intravenous continuous infusion capable of providing comfort for the patient with great analgesic action and muscle relaxation for cats subjected to elective surgeries like ovariohysterectomy and orchiectomy. Thirty cats were randomly distributed in 3 groups of 10 animals each. All animals were tranquilized with acepromazine (0.1 mg/kg IM) and general anesthesia was induced using propofol (6mg/kg, IV). In group 1, general anesthesia was maintained by continuous infusion of propofol (0.6 mg/kg/min); in group 2, with propofol (0.4 mg/kg/min) and remifentanil (0.1 µg/kg/min) and; in group 3, with propofol (0.4 mg/kg/min) and remifentanil (0.2 µg/kg/min). The measured variables were: temperature, heart rate, respiratory rate, oxyhemoglobin saturation, systolic arterial pressure, arterial blood gas analysis, analgesia and myorelaxation. Results of the analyses led to the conclusion that remifentanil promoted an increase in analgesia, allowing a 33% reduction on the rate of propofol infusion, although the infusion of 0.2 µg/kg/min of remifentanil determined a greater respiratory depression when compared to the 0.1 µg/kg/min infusion.
Anesthesia; hemosametry; analgesia; propofol; remifentanil; feline
