Avaliação do efeito procinético e analgésico da lidocaína endovenosa em equinos submetidos à endotoxemia experimental | Evaluation of the prokinetic and analgesic effects of intravenous lidocaine in horses subjected to experimental endotoxemia

Lidocaine hydrochloride is used as an analgesic and intestinal prokinetic in horses, notable for its good tolerance to prolonged intravenous infusions. However, despite its widespread application, variability in results and a lack of controlled studies in with endotoxemic horses. In this study conducted at the EQUINOVA Research Center, seven horses took part in a randomized crossover clinical trial, distributed between the Lidocaine Group (GL) and Control Group (CG). In GL, the animals received intravenous lidocaine (1.5mg/kg bolus infused over 15 minutes, followed by a continuous infusion of 0.05mg/kg/min for a period of eight hours). Meanwhile, the GC horses received sodium chloride infusions. One hour later, we administered a 30-minute infusion of 0.03μg/kg Escherichia coli O55:B5 lipopolysaccharides to induce reversible endotoxemia in all horses. The evaluation included auscultation and abdominal ultrasound, in addition to analgesia analysis, together with the observation of physical and hematological parameters. There were no significant clinical differences between the GL and CG groups in relation to analgesia and intestinal kinesis, regardless of the infusions administered or after endotoxemia induction. These results do not support the clinical use of lidocaine in these specific circumstances and the outcome emphasizes that, even at previously established doses, lidocaine was not effective in reducing abdominal pain and hypomotility caused by LPS-induced endotoxemia. Numerous factors such as individual variability in sensitivity to lidocaine, contribute to the lack of significant therapeutic responses, the specific nature of endotoxemia and the complexity of physiological interactions in horses. This study contributes to the understanding of the role of lidocaine in these specific conditions and highlights the continued need for research to improve the clinical management of these complex situations.

FAPEMIG - Fundação de Amparo à Pesquisa do Estado de Minas Gerais