Efeitos da anestesia epidural com tramadol, ropivacaína ou sua associação, em cadelas submetidas à ovariosalpingohisterectomia sob anestesia com isoflurano

Abstract

Epidural anesthesia is a locoregional anesthetic technique that provides analgesia and muscle relaxation in retroumbilical region. The combination of opioids and local anesthetics contributes to increasing the intensity and prolongation of analgesia occurring immediately motor and sensory block, improving recovery after surgery. The aim was to comparatively evaluate the trans- and postoperative cardiorespiratory effects and analgesia provided by tramadol, ropivacaine or its association, epidural, and the anesthetic requirement of isoflurane during surgery, in canines undergoing elective ovariohysterectomy. This study was performed with 24 female canine species, pre-medicated with chlorpromazine (0.5mg/kg IV), anesthetized with propofol (the effect) and isoflurane and randomly divided into three groups, which was employed in epidural 2mg/kg tramadol (GT), 1.5mg/kg ropivacaine (GR) or their association (GTR) in the above-mentioned doses. In pre-defined times, the periods before, during and postoperative, cardiorespiratory variables and analgesia were analyzed for a period of up to 420 minutes after epidural anesthesia. Analgesia was observed of approximately 105, 217 and 382 minutes, in GR, in GT and GTR respectively, and there was nor cardiovascular neither respiratory depression. The drugs tested in this study can be considered safe and effective in the surgical technique in question due to cardiorespiratory stability and trans-operative analgesia, however, the combination of ropivacaine and tramadol promoted greater reduction in inhaled anesthetic and better analgesia in the postoperative period.