Micro-aggregate content of red cell suspensions stored in saline adenine glucose mannitol optimal additive solution

The micro-aggregate content of blood collected into conventional CPDA-1 preservative was compared with that of red cells stored in saline adenine glucose and mannitol optimal additive preservative solution (SAG-M). The results show that the optimal additive packs from which either platelet rich or platelet poor plasma have been removed contain 38% of the micro-aggregates in CPDA-1 blood. When platelets, plasma and the buffy coat are also removed, the residual micro-aggregates amount to only 16% of those in CPDA-1 whole blood. No differences were seen between the amount of haemolysis in any of the red cell preparations. From these results and previously published guidelines for the use of micro-aggregate filters with whole blood (International Forum 1977) it may be concluded that there is no place for the routine use of micro-aggregate filters with optimal additive preserved blood unless over 12 units are likely to be transfused.