Ropivacaine individually and in combination with fentanyl or tramadol, administered by peridural via in dogs

Peridural anesthesia is broadly applied in the Veterinary field, using the isolated local anesthetic or in combination with opiates capable to increase the analgesic effect. This research compared analgesia and cardiorespiratory effects of epidural anaesthesia produced by ropivacaine alone or combined with fenanyl or tramadol in eight mixed breed adult dogs after sedation with acepromazina. Drugs were administered on the following protocols; GR (ropivacaine), GRF (ropivacaine + fentanyl), GRT (ropivacaine + tramadol), in 0.25ml kg(-1) of total volume. Heart and respiratory rate, rectal temperature, blood pressure and, gastrometry of atrial blood were mensured, as well the sensory and motor blockade (latency and period of action), degree of sedation and side effects. The most important decrease of the heart rate occurred in GRF and GRT. Also significant hypothermia in GRF. Intense degree of sedation was observed in GRF and GRT. The period of recovery was shorter in GRT. The most cranial region of blockade occurred in GRT. Bradicarida, hypothermia and Shiff-Sherrington syndrome were observed in the transanesthetic period in animal from all of the groups. During 24 hours after the anaesthesia no side effects were observed. The GRF had the longer period of anesthesia with intermediate analgesia and, GR presented intermediate period of anesthesia with lower degree of analgesia. Respiratory and hemogasometrics change were not found, but hipotermy, brandicardy and Schiff-Sherrington syndrome, side effects usually seen in peridural anesthesia, were observed in this study.