Predictors indicating the effective ecmo support in experimental septic shock

Abstract

Background: In septic shock, the determinants of a successful ECMO treatment remain uncertain. We investigated if cardiac performance parameters and lactate levels can predict outcome in a rat model of ECMO for septic shock. Materials and methods: Eighty Sprague-Dawley rats were divided into 4 groups: Controls (n=20), Septic shock (n=20), ECMO (n=20), ECMO for Septic shock (n=20). In all 4 groups, cardiovascular parameters by pressure-volume (PV) loop study, lactate levels, and histology of the heart was performed. The groups were compared among each other. The correlation between cardiac parameters and lactate/pressure-volume area (PVA), which reflects systemic perfusion/myocardial O2 demand, was analyzed for ECMO for Septic shock group. Results: The PV loop shifted to the right in both the ECMO group and ECMO for the septic shock group. The changes were more significant in ECMO for the septic shock group compared to other groups. In regression analysis, arterial elastance before ECMO initiation was positively correlated with lactate level after 2 h of ECMO. (β=2.732, p=0.009). Ejection fraction before ECMO initiation was positively correlated with PVA after 2 h of ECMO. (β=0.672, p=0.012) Conclusion: In our experimental study, the PV loop significantly shifted in both the ECMO group and the ECMO for the septic shock group suggesting ECMO itself might distress the cardiac performance. In the septic shock experimental model, the higher arterial load before ECMO initiation might be related to poor systemic perfusion. Also, the higher myocardial contractility before ECMO initiation leads to the higher myocardial O2 demand.L6362634452021-10-26 <br />