Red cell transfusion "trigger": a review

Despite the publication of several consensus guidelines that set forth recommendations for the transfusion of red cells, actual clinical practice continues to vary widely. Animal data and studies in human volunteers and patients support a red cell transfusion threshold of 7 to 8 g/dl in most patients. However, conflicting data, particularly in cardiac patients and in the elderly, suggest that it may be impossible to define a single red cell "trigger" for all patients. A well-designed, randomized, controlled trial is still needed to establish a safe threshold for red cell transfusion in adults with coronary artery disease.