Bloqueio do plano transverso abdominal por visualização direta em cadelas

Abstract

In Veterinary Medicine, the transversus abdominal plane (tap block) guided by ultrasound has proven effective in various surgical procedures. Recently, a new approach to the tap block was described in a cadaveric study conducted on dogs, where the block is performed by the anesthesiologist through direct visualization with an intra-abdominal approach, after the surgeon makes a surgical incision. Until this study, no investigations or studies had been conducted in the literature regarding the analgesic efficacy of this new technique in live dogs. Therefore, this prospective and planned study aimed to evaluate the analgesic efficacy by comparing the tap block techniques and the need for rescue analgesia during the intraoperative and postoperative periods, based on the baseline physiological parameters of female dogs undergoing ovariohysterectomy. The research included the evaluation of 10 female dogs, aged between 10 months and 6 years, and weighing between 3 and 10 kg, with no specific breed defined. The animals were divided into 2 groups of 5 each: in the first group (G-US), a closed ultrasound-guided approach was performed, and in the second group (G-VD), the tap block was performed with direct visualization. The animals were pre-medicated with Methadone at a dose of 0.3 mg/kg in both groups, and anesthesia was induced with propofol at a dose of 4 mg/kg intravenously, administered at a rate of 1.0 mg every 30 seconds, and maintained with isoflurane diluted in O2. The local anesthetic of choice for the block was bupivacaine, at a dose of 0.3 mL/kg/injection point at 0.25%, with the total volume divided between each injection point on each side of the abdomen. The animals were then monitored in the postoperative period for rescue analgesia and pain assessment using the visual analog scale (VAS) and Glasgow scale for 24 hours. The results showed no significant differences between the groups during the intraoperative period, and in the postoperative period, both groups had one patient that required rescue analgesia, although at different times. Based on the findings, it was concluded that the new direct visualization approach of the tap block provides effective analgesia, similar to the ultrasound-guided approach, in the postoperative period of female dogs undergoing ovariohysterectomy. The study confirmed that the new approach could be a viable alternative for pain management in ovariohysterectomy procedures in female dogs, offering several advantages, such as reducing anesthesia time due to its faster technique compared to ultrasound-guided methods, and lowering the costs associated with its implementation.