Evaluation of posttransfusion recovery and survival of transfused red cells.

Increasing diversity of red cell preservation solutions has required more attention to the techniques of documenting the in vivo efficacy of stored red cell transfusion products. Use of double labels and survival studies will not only improve the precision of the measurement but, hopefully, will offer insight into some of the effects of the newer preservation systems. Further development of the low chloride hypotonic red cell storage solutions pioneered by Meryman may well result in red cell transfusion products that can be stored liquid in vitro for more than twice the normal in vivo lifespan. Verifying that such cells not only are recovered in the circulation but survive for the normal in vivo lifespan and function correctly will demand increasingly accurate techniques. The combination of assay precision and external imagability render radionuclide techniques the standard for verifying red cell efficacy despite the small disadvantage of the radiation absorbed dose.