3.6 Red blood cell transfusion in chronically transfused patients

Patients requiring chronic RBC transfusions account for a significant proportion of blood usage. This includes patients with ß thalassaemia major, sickle cell disease and myelodysplasia. Hence, appropriate use of red blood cells in these patients is of great importance, both for patient welfare and for the appropriate use of a scarce and valuable resource.

Chronic hypoproduction of RBCs means that regular transfusions are generally required to maintain the Hb at a particular level. The 2001 Clinical Practice Guidelines on the Use of Blood Components¹ indicated that maintaining Hb at >80 g/L was likely to be appropriate on the basis of physiological principles. These patients are usually managed as outpatients. Hence, for practical reasons, they are often prescribed a predetermined number of RBC units (intended to achieve a defined Hb concentration), rather than having their response assessed after each unit. In addition, these patients may be deliberately transfused to a higher level of Hb than is physiologically necessary, in an attempt to maximise the interval between transfusions. This decision making appears to be based on historical practice; the triggers for initiating transfusion in such patients are different to the triggers for patients with anaemia who do not have bone marrow dysfunction.

Due to the chronic nature of the disorder, patients with chronic anaemia may receive multiple transfusions over a long period. Therefore, in addition to the usual risks associated with transfusion, patients are at risk of complications such as human leukocyte antigen (HLA) and red cell alloimmunisation, and iron overload. For the latter, use of chelation therapy should be considered.