Blood preservation considering the possibilities, the patient and the purse.

An efficient motivation for the clinician to use blood components instead of whole blood is that the components have improved quality. Systems of integrally connected plastic bags makes the preparation easy and safe. This means that the blood can be collected in a solution which is not at the same time the storage medium. The anticoagulant may--but must not necessarily--be one of the conventional solutions, ACD or CPD. Adenine and possibly guanosine should preferably be added to a separate red cell suspension medium which can simply consist of sodium chloride, adenine and glucose. In order to avoid elevated hemolysis, sucrose or mannitol can be enclosed in the medium, if the protein concentration is low. Control of pH by a buffering system or an ion-exchange device is a necessity if the liquid storage shall be possible for more than 5--6 weeks. An interesting new possibility to improve the storage conditions is to introduce a chemical coupling of heparin onto the inner surface of the plastic bag.