ELETROCARDIOGRAFIA DE CÃES SUBMETIDOS A DIFERENTES CONCENTRAÇÕES DE DESFLURANO, PRÉ-TRATADOS OU NÃO COM A ASSOCIAÇÃO DE FENTANIL/DROPERIDOL ELECTROCARDIOGRAPHY OF DOGS UNDERGOING DIFFERENT DESFLURANE CONCENTRATIONS, PREMEDICATED OR NOT WITH FENTANYL/DROPERIDOL ASSOCIATION

SUMMARY The aim of this work was to evaluate the effects of the fentanil/droperidol association over the heart rate (HR) andelectrocardiography (ECG) of dogs submitted to anesthesia bydesflurane. For that, forty healthy adult dogs, males and females were used. The dogs were equally separate in two groups G1 and G2. G1 received fentanil (15.7 µ g/kg) associated to droperidol(0.5mg/kg); while G2 received saline solution at 0.9% (placebo), both applied intravenously. After 15 minutes the generalanesthesia was induced with intravenously administration ofpropofol (5mg/kg). The dogs were submitted to inhalatoryanesthesia with desflurane, with an initial concentration of 1.6MAC. The observations of the variables were begun immediately before the application of the agents (M1). New measurings were carried out 15 minutes after the administration of thefentanil/droperidol association or placebo (M2) and 20 minutesafter the anesthetic induction (M3). The other measuringscoincided with the establishment of the concentrations of 1.4; 1.2 and 1.0 MAC, respectively M4 to M6. The numeric data weresubmitted to the Analysis of Profile, being considered the level of significance of p<0.05. The results allowed to conclude that the fentanil/droperidol association decreases HR and the desflurane blocks the decrease on HR produced by the association andpromoves a delay in the electrical atrial and ventricularconduction.