Venous Oxygen Saturation During ECMO Support (ECMOxygen)

Extracorporeal veno-arterial membrane oxygenation" (ECMO-VA), are used to manage refractory cardiogenic shocks by replacing the failed "heart-lung" block. The Extracorporeal Life Support Organisation guidelines considers that the effectiveness of these techniques must be evaluated on the adequacy of tissue perfusion biomarker, of which is O2 saturation of venous blood found in the pulmonary artery using a Swan-Ganz catheter (SVO2) or in the superior vena cava/right atrium using a central venous catheter (ScVO2). During ECMO support, it can be also measured directly in the venous ECMO cannula (SmVO2).

However, due to the difference in tips locations of the venous cannula of ECMO-VA, the central venous catheter and the Swan-Ganz catheter, and rheological issues, the SmVO2, SVO2 and ScVO2 values obtained may be different.

Further we hypothesised that the level of admission flow may also affect the correlation between these different variables.

The aim of this experimental study is to investigate the concordance of the saturation of venous blood collected from these 3 measurement sites.

The primary objectives is to compare the concordance of ScVO2 and the SmVO2, the two more easily and systematically available variables

The secondary objectives were :

1. to evaluate the concordance of the 3 variables describing oxygen saturation
2. to analyse the primary objectives during prespecified and calibrated flow changes
3. analyse the association between these 3 variables with prognosis variables (Perfusion index, lactatemia, CO2 veno-arterial differences, SOFA score, SAPS II, successful weaning from the ECMO)
4. analyse in an ancilary study the concordance between SmVO2 measured using blood sample and the value obtained using a continuous monitoring of SVO2 through the circuit.