Individualized or Conventional Transfusion Strategies During Peripheral VA-ECMO

Peripheral VA-ECMO is the mainstay of mechanical circulatory support in refractory cardiogenic shock. This treatment is associated with a high consumption of packed red blood cells (PRBCs), which can reach 1 to 3 units of PRBCs per day of support. The main reasons for such a high consumption of PRBCs are the very frequent hemorrhagic complications and the prevalence of anemias not directly related to the hemorrhagic episodes. These anemias are frequent during VA-ECMO support owing to hemolysis, hemodilution, previous bleeding episodes, thrombosis, etc.

In order to restore, maintain, or increase oxygen delivery (DO2) to peripheral organs, RGCs are often performed when anemia is observed. Several studies have reported an association between transfusion of these PRBCs with morbidity and mortality in this ECMO setting.

There is no appropriate strategy to reduce PRBC consumption, taking into account other determinants of DO2. In addition, there is currently no validated or consensus hemoglobin threshold to guide transfusion in this specific population. Furthermore, this predefined threshold-based approach may be inappropriate in the setting of VA-ECMO due to differences in DO2 requirements between patients based on their etiology, disease severity, and ECMO modality. In addition, large variations in DO2 can be observed in the same patient and between ECMO settings. Therefore, a more individualized strategy guided by a DO2 surrogate, ScVO2, may be more appropriate in this population. This ScVO2 approach has recently been shown to be associated with reduced PRBCs in two randomized controlled trials in cardiac surgery patients.

The objective of this multicenter randomized controlled trial is to compare two red cell transfusion strategies in patients receiving extracorporeal veno-arterial membrane oxygenation for refractory cardiogenic shock.

An individualized transfusion strategy based on ScVO2 level is compared with a conventional strategy based on a predefined hemoglobin threshold. The primary endpoint is red blood cell consumption, the secondary endpoints are subgroup analysis, mortality, morbidity, and cost-effectiveness.

Inclusion criteria

• Age of 18 and older,
• supported by peripheral VA-ECMO
• for cardiogenic shock
• Life expentency >90 days
• Central venous line available ScVO2 measurement

Exclusion criteria

• Pregnancy,
• Lack of health insurance,
• Opposition to blood transfusion,
• Known congenital hemoglobin disease or disorder,
• Metabolic alcaloosis with pH>7.8,
• eCPR,
• Legally incapacitated adults