SHALL RED-CELL UNITS STAND UPRIGHT, LIE FLAT OR BE MIXED DURING STORAGE - IN-VITRO STUDIES OF RED-CELLS COLLECTED IN 0.5 CPD AND STORED IN RAS2 (ERYTHROSOL(R))

Red cells were prepared using a new anticoagulant with half the normal amount of citrate and a new additive solution (RAS2, Erythrosol(R)) p reviously shown to give improved storage conditions, and stored in a h ighly gas permeable plastic container (PL 2209). Mixing daily and week ly resulted in lower PCO2, higher PO2 and more rapid oxygen saturation of the haemoglobin than storage unmixed in an upright position. Stora ge horizontally in a lying position unmixed resulted in similar blood gas values as with mixing. The haemolysis was lowest in units mixed on ce weekly: 0.21 +/- 0.09% after 28 days and 0.26 +/- 0.06% after 56 da ys. The morphology was better maintained in mixed than in unmixed unit s. Horizontal storage and mixing once per week seem to be optimal as j udged from these in vitro studies.