Abstract 15309: Evaluation of a Fuzzy Logic Control System for Hypotensive Resuscitation in a Swine Model of Hemorrhagic Shock

Introduction: Closed-Loop resuscitation (CLR) system has been developed and tested in different animal models of hemorrhagic shock. It is an autonomous control technology of fluid therapy through real-time monitoring and feedback of physiological signal. However, currently vital signs (eg, blood pressure) are inadequate for early detection of saving-life intervention during pre-hospital. We have early confirmed that buccal mucosal CO 2 partial pressure (PbuCO 2 ) can be effectively used for identifying the severity of hemorrhagic shock. In this study, we investigated whether a fuzzy logic based CLR system that used MAP and PbuCO 2 as feedback parameters could be more effectively than gravity infusion (GI) for prolonged hypotensive resuscitation in a swine model of hemorrhagic shock. Hypothesis: We hypothesized that the CLR system used MAP combined with PbuCO 2 may guide fluid resuscitation to improve outcome in animal. Methods: 24 pigs were randomly divided into two groups, CLR and GI. Lactated Ringer’s Solution was administered to achieve MAP of 65mmHg and PbuCO 2 of 75mmHg. A fuzzy logic control system was developed to drive a programmable micro electromagnetic linear actuation pump, which was automated infusion in the CLR group. It is according to physician orders treatment in the GI group. Resuscitation was performed for 2h in both groups. Hemodynamic, microcirculation and metabolic parameters were monitored during the study. Results: There were three animal deaths within 72h of surgery. One animal died 24h after surgery in the CLR group. In the GI group, one animal died at 12h and another died at 24h after surgery. After 120min of resuscitation, the per cent change from baseline of the perfusion units (PU) of the CLR group were less than that of the GI group (10.97±4.02% versus -4.07±4.22%, P Conclusions: The use of MAP combined with PbuCO 2 as the endpoint of a fuzzy logic based CLR system for prolonged hypotensive resuscitation was associated with a smaller volume of infusion and higher survival rate than gravity infusion.