Gastric tonometry and impedance spectroscopy as a guide to resuscitation therapy during experimental septic shock in pigs

Background: This work investigates the potential value of combined splanchnic perfusion and tissue injury measurements as a guide to resuscitation therapy during an experimental model of septic shock in anesthetized pigs. Materials and Methods: An endotoxic shock model in 22 male pigs was developed by intravenous infusion of lipopolysaccharide. Three experimental groups were designed: a control group, a therapy group whose intervention was guided by haemodynamic variables, and a therapy group whose intervention was guided by splanchnic tissue indicators. The control group was allowed to progress into septic shock without intervention. The animals were subjected to resuscitation protocols with fluids and catecholamines depending on their responses, either to haemodynamic variables in one treatment group, or to measurements of pH_i combined with an ischemic injury classification given by gastric impedance spectroscopy in the other treatment group. Resuscitation protocols were designed to promote changes in haemodynamic responses as well as splanchnic perfusion. A Kaplan-Meier survival analysis was estimated in each group. Results: Survival in both treatment groups was significantly better than in the control group. There was no significant difference in the survival outcome between treatment groups. Conclusion: Splanchnic tissue indicators have the potential of being used as complementary tools for guiding the appropriate treatment of septic shock. The results justify the need for further studies in order to determine the best use of gastric tonometry and spectroscopic impedance information in clinical practice.