Currently blood is a volatile issue. The safety of blood and the quantification of transfusion risks have been dominant themes that have stimulated the development of alternative approaches in this rapidly developing area. In clinical medicine conventional blood and its components are used in supportive therapies dependent on the choice of apparent uncritical trigger factors. A compounding factor is depth of prospective clinical trials for evidence. Such trials in critical care areas would be of enormous value, not only in recording adverse effects and under-transfusion, but also indicating...