Restrictive Versus Liberal Thresholds for RBC Transfusion in ECMO

Rationale: In patients supported with extracorporeal membrane oxygenation (ECMO), transfusion of red blood cells (RBC) is very common. This is possibly due to the application of liberal thresholds and the lack of evidence-based guidelines. Although RBC transfusion can be lifesaving, it is also a risk-bearing intervention with substantial risk for morbidity and mortality in this critically ill population. Also, with increasing scarcity, RBC transfusions are becoming more expensive. Furthermore, in the past decades it has been shown in several critically ill patient populations - not on ECMO - that maintaining a restrictive hemoglobin (Hb) threshold for RBC transfusion is non-inferior, including in cardiothoracic surgery, acute myocardial infarction and septic shock. Therefore, the investigators hypothesize that a restrictive transfusion threshold for RBC is safe to apply in patients on ECMO in comparison with a liberal transfusion threshold.

Objective: The primary objective of this trial is to study in a prospective randomized comparison whether a restrictive RBC transfusions strategy is non-inferior compared to a liberal strategy in patients on ECMO with respect to 90-day mortality.

Study design: Prospective multi-center randomized controlled non-inferiority trial.

Study population: Patients, 18 years or older, receiving ECMO.

Intervention: Restrictive RBC transfusion threshold: in case the Hb transfusion trigger of 7.0 g/dL (4.3 mmol/L) is reached, 1 RBC unit at a time will be transfused. The aimed Hb target range of the restrictive/intervention group will be 7.1 - 9.0 g/dL (4.3 - 5.6 mmol/L). Liberal RBC transfusion threshold: in case the Hb transfusion trigger of 9.0 g/dL (5.6 mmol/L) is reached, 1 RBC unit at a time will be transfused. Target range of the liberal group is defined as Hb 9.1 - 11.0 g/dL

Main study parameters/endpoints: The primary outcome parameter is 90-day all-cause mortality.

Secondary outcomes include: 1) proportion of patients on ECMO exposed to allogeneic RBC transfusion; 2) RBC volume infused per patient during ECMO; 3) reasons for RBC transfusion other than Hb triggers; 4) transfusion reactions; 5) time on ECMO; 6) length of hospital- and ICU-stay; 7) in-ICU morbidity; 8) quality of life (QoL), iMTA Medical Consumption Questionnaire (iMCQ) and Productivity Cost Questionnaire (iPCQ) at 3, 6, 9, and 12 months; 9) costs related to a) transfusion, b) hospital admission and c) transfusion-related sequelae.