When a patient has experienced severe allergic reactions associated with transfusion, reactions to subsequent transfusions may be prevented by the use of red cells that have been washed in sterile saline using special equipment.

This should remove residual plasma proteins cytokines or antibodies that may be the cause of the reactions. Saline washed RBCs must be used within 24 hours after washing since the saline contains no red cell nutrients and the original collection bag has been entered with consequent risk of bacterial contamination.