Optimal Settings at Initiation of Veno-Venous Extracorporeal Membrane Oxygenation: An Exploratory In-Silico Study

The Extracorporeal Life Support Organisation (ELSO) recommends initiating veno-venous extracorporeal membrane oxygenation (ECMO) with sweep gas flow rate () of 2 L/min and extracorporeal circuit blood flow () of 2 L/min. We used an in-silico model to examine the effect on gas exchange of initiating ECMO with different and , and the effect of including 5% in sweep gas. This was done using a set of patient examples, each with different physiological derangements at baseline (before ECMO). When ECMO was initiated following ELSO recommendations in the patient examples with significant hypercapnia at baseline, sometimes fell to < 50% of the baseline , a magnitude of fall associated with adverse neurological outcomes. In patient examples with very low baseline arterial oxygen saturation (), initiation of ECMO did not always increase to > 80%. Initiating ECMO with of 1 L/min and of 4 L/min, or with sweep gas containing 5% , of 2 L/min, and of 4 L/min, reduced the fall in and increased the rise in compared to the ELSO strategy. While ELSO recommendations may suit most patients, they may not suit patients with severe physiological derangements at baseline.