Estudo comparativo entre o bloqueio combinado dos nervos femoral e ciático e a anestesia epidural lombossacra, em coelhos (Oryctolagus cuniculus) submetidos à osteossíntese femoral

Abstract

Rabbits have been widely used as an experimental model, however they are easily stressed and can present depression of the central nervous system with general anesthesia, as safer alternatives arise in this context the techniques of locoregional anesthesia. The aim of this study was to evaluate the efficacy of combined femoral-sciatic nerve block as the sole analgesic protocol, by approaches not yet reported in rabbits, comparing it with the already established epidural technique in patients undergoing femoral osteosynthesis surgery. Initially, four animals were dissected to determine the anatomical delimitations and the volume to be used to block the peripheral nerves. Subsequently, 16 rabbits were divided into two groups (epidural and femoral-sciatic) of eight animals each. The animals underwent femoral osteosynthesis surgery and the physiological parameters (heart and respiratory rate, oximetry, systolic, mean and diastolic blood pressure and rectal temperature) were evaluated during the procedure. Postoperative pain was assessed using the modified Wenger pain scale. During the intraoperative period, the animals maintained the stability of cardiovascular and respiratory variables and in the postoperative period did not demonstrate behavior suggestive of pain, thus requiring no additional analgesia at any time in the study. Patients in the group who used the combined technique had a better gait when walking with three supports in the postoperative period when compared to those in the epidural group. It was concluded that the combination of femoral and sciatic nerve blocks is an excellent alternative to epidural anesthesia in rabbits submitted to femoral osteosynthesis surgery.