Studies on blood coagulation activity during storage of red cell products intended for transfusion.

Preservation of red blood cells in special media, such as saline-adenine-glucose-mannitol (SAGM) solution involves storage at a citrate and plasma protein concentration much lower than found in normal CPD or CPD-adenine plasma. In the present study, the effects on the coagulation and other connected enzymatic systems in SAGM medium have been investigated. Significantly higher levels of fibrinopeptide A (FPA) and plasma kallikrein activity were observed in the SAGM medium compared to CPD plasma, indicating an increased enzymatic activation in the SAGM medium. For this reason storage of red cells in SAGM solution, supplemented with citrate, was tested and compared with storage in SAGM and CPD plasma. The results demonstrate a positive effect of citrate as an added ingredient in the SAGM solution. Significantly lower levels of primarily FPA but also decreased activities of plasma kallikrein and general proteolysis were noticed. The decreased citrate concentration in Red Blood Cells stored in SAGM protein poor medium must be considered to have a destabilizing influence on the coagulation and on other connected enzymatic systems.