Current recommendations for RBC transfusion [75, 76] are mainly based on the famous "TRICC" (Transfusion Requirements In Critical Care) trial in which patients assigned to a restrictive transfusion strategy (transfusion if hemoglobin level < 7 g/dl) had similar 30-day mortality rates (and even lower mortality in subgroups with APACHE II < 20 and patients younger than age 55 years) than patients transfused according to a more liberal strategy (transfusion if hemoglobin level < 10 g/dl) [77] . In cardiac surgery patients, the recent randomized, monocenter "TRACS" (Transfusion Requirements after Cardiac Surgery) trial, which compared a restrictive to a liberal strategy (transfusion when hematocrit < 24% or < 30%, respectively), reported no difference in the primary endpoint (composite of 30-day mortality and morbidity [cardiogenic shock, ARDS, acute kidney injury]) between the groups [78] .