Efeitos cardiorrespiratório, analgésico, sedativo e neuroendócrino de diferentes doses de tramadol em cães

Abstract

This double-blind study compared the cardiorespiratory, analgesic, sedative and neuroendocrine effects of different doses of tramadol administered intravenously (iv) in bitches, submitted to ovariohisterectomy. The animals were randomly assigned to three groups of 08 animals each, and treated with doses of tramadol in1mg kg-1 (GT1), 2mg kg-1 (GT2) and 4mg kg-1 (GT4). The pre-anesthetic medication administered was acepromazine (0.05 mg kg-1 iv), the anesthetic induction was performed with propofol (4mg kg-1 iv), and subsequent maintenance with general inhalatory anesthesia with isoflurane. The tramadol was administered 5 minutes after general inalatory anesthesia in all groups. Heart rate, respiratory rate, rectal temperature, systolic blood pressure, degree of analgesia and sedation, serum cortisol concentration and adverse effects were measured. In relation to analgesia degee there was not difference between the groups, excepted in the 3rd h after surgery, when GT4 group had lower pain scores than other groups. In the cardiorespiratory, mild alterations were observed, without difference between the groups. Sedation degree was not different between the groups, with lower scores until the 3rd h after to the end of surgery. The serum cortisol did not differ between the groups, although an increase was observed in the trans-operative period until the 3rd h after to the end of surgery. Vomit was observed in 50% of the dogs. It was concluded that the different doses of tramadol promoted satisfactory analgesia, with mild sedative and cardiorespiratory effects in bitches submitted to ovariohisterectomy.