[Changes in erythrocyte deformability in blood preservation].

The deformability changes of erythrocytes during storage were characterized by a filtration procedure for blood units mainly used for erythrocyte substitution in the GDR. Following order of maintaining deformability properties were measured: 1. At-196 degrees C cryopreserved erythrocytes; 2. whole blood units; 3. at-28 degrees C cryo-preserved erythrocytes (in clinical examination); 4. buffy-coat free erythrocyte concentrates resuspended with CDS-AG medium. The drastic deformability loss of CDS-AG resuspended erythrocytes (75% of all erythrocyte transfusions!) is caused by an increase of the internal viscosity due to a practically irreversible shrinkage of erythrocytes as an effect of low ionic strength. In contrast to former data a reinvestigation of in vivo survival resulted in values 20% below the limit of 70% 24 h p.i. In comparison to this the abroad used CPDA-1 whole blood units and SAGM resuspensions showed only small deformability changes during storage. By a change of composition of the GDR-resuspension medium the drastic deformability loss is avoided. This new resuspension medium is concerning the deformability loss comparable to the SAGM medium. A comparison of deformability changes during storage in plastic bags and glass bottles as well as in media with various hemolysis reducing agents did not show any differences.