[Blood preservation. Bacteriological, immunohematological, hematological and hemorrheological studies].

The knowledge of erythrocyte viability during blood bank storage period has been a major problem for transfusional practice. This problem must be considered by taking into account blood flowing properties which are directly related to the rheological properties of erythrocytes. The aim of this work was to perform an interdisciplinary study of the modifications induced in erythrocyte properties during 29 days storage of whole blood in a blood bank. Three samples of venous blood collected from healthy adults in plastic bags, anticoagulated with ACD (citric acid, citrate, dextrose) and stored at 4 degrees C were studied. Rheological properties (deformability, membrane elasticity and surface viscosity), immunohematological conditions (antigenicity) of erythrocytes, haematological index variation and bacteriological cultures of blood were weekly analysed. Rheological studies were performed using the Erythrodeformeter, a polymicroviscosimeter (paper filter) and erythrocyte filtration through polycarbonate membranes of 5 microns pore diameter. Impairment of membrane rheological properties, loss of antigenicity and decreases of Ht, Hb, MCHC and MHC were observed. Bacteriological cultures gave always negative results. The studies performed showed significant alterations of erythrocyte rheological parameters. It becomes evident that such modifications would influence the erythrocyte mechanical behavior in microcirculation and impair the in vivo viability of the transfused red cells.