STORAGE DEPENDENT CHANGES IN THE STORED-B LOOD OF CATS

In the present study, storage dependent effects were investigated in 1 0 blood preserves of the cat over a period of 42 days. During this sto rage time, no striking changes of the erythrocyte count were shown, wh ile the haematocrit decreased by 1.5%. A significant increase of the p lasma haemoglobin concentration, which was certainly neglectable compa red to the blood haemoglobin, pointed indeed at a partially increased permeability of the erythrocyte cell membrane or a damaged erythrocyte structure. The leukocyte and platelet number decreased distinctly dur ing storage, to some extent as a result of aggregation. For that reaso n, the transfusion of a blood preserve is primarily indicated for the correction of an anaemia. Additional distinct storage dependent change s were the increasing concentration of Na+, K+ and total protein in th e blood preserve, expressing the damage of cells, too. The pH decrease owing to a distinct loss of buffer base capacity such as the diminuti on of the blood glucose concentration in the blood preserve expressed the metabolism activity of the erythrocytes. The gas permeability of t he PVC-bag could be read from the decreased pCO2 and the increase in p O2. The latter was rendered possible by an increasing O2 affinity of t he haemoglobin. Besides the quality loss, mirrored by a decrease of in tact cells, storage consequently causes also changes (formation of mic roaggregates, K+-increase, pH-decrease), which are able to damage dire ctly the receiving animal. While transfusion of microaggregates can be prevented by adding a microfilter, the altered pH and increased K+-co ncentration have to be considered when transfusing a great volume of s tored cat blood to an intensive care patient.