Blood banking is a medical logistic activity. It attempts to bring the potentially life-saving benefits of transfusion to the patients who need them by making blood components available, safe, effective and cheap1. Blood banks try to maximize delivering getting blood from the right donors to the right patients in a timely manner. The easiest way to assure the timely availability of blood is to have an appropriate inventory on the shelf at all times.
Standards for blood banking have evolved in response to problems observed in the past. Donors need to be free of syphilis, hepatitis, and human immunodeficiency virus (HIV) and from a host of other diseases as well. Methods for cleaning the arms of donors should work. Blood bags should contain the appropriate solutions and be sterile. Systems for the identification of donors and patients, for the determination of antigens on their blood cells and the antibodies in their sera, and for the procedures and processes used to gather and maintain this information should be robust.
Regulatory agencies, like the United States (U.S.) Food and Drug Administration (FDA), are charged to assure that blood products are safe and effective. They attempt to assure safety by enforcing the standards noted above. They attempt to assure effectiveness by demanding demonstrations that a reasonable fraction of red cells, platelets and plasma proteins survive after storage before licensing new blood storage systems or blood modifying products like leukocyte reduction filters4,5. Yet the reasonable fraction for red cells is 75%, for platelets is 67%, and for plasma proteins is 80%. Standards, such as insisting that every unit of blood be tested for HIV, work only if the licensed tests detect the circulating viruses, a moving target.
Better understanding of the basic biology and better tests on which to base better standards are needed. If we understood the changes that occur with the storage of red cells, platelets and plasma better, we could both design better storage systems and regulate storage more effectively. If we knew more about the viruses and bacteria and the cytokines and blood breakdown products that threaten blood safety we could institute controls to further improve blood safety. This paper will explore some specific examples.