HALF-STRENGTH CITRATE CPD AND NEW ADDITIVE SOLUTIONS FOR IMPROVED BLOOD PRESERVATION .2. THE EFFECT OF STORAGE AT AMBIENT-TEMPERATURE BEFORE COMPONENT PREPARATION AND DIFFERENT MEANS OF SUPPLYING GLUCOSE TO THE RED-CELLS

In current anticoagulant-additive systems used for the preparation of blood components an early loss of erythrocyte 2,3-bisphosphoglycerate (BPG) during storage is unavoidable. This increases reversibly the oxygen affinity of the haemoglobin of red blood cells (RBC). Using half-strength citrate CPD solution (0.5CPD) as anticoagulant and a red-cell additive solution (RAS 2) containing citrate, adenine, phosphate, mannitol and glucose, it was possible effectively to counteract this undesirable effect without loss of adenine nucleotides. The initial mean BPG level was maintained for 4 weeks and the total adenine nucleotide concentration for 7 weeks. The initial BPG level decreased upon prolonged hold of the whole blood at ambient temperature to 85-90% of normal after 4 h, 70% after 12 h and 50% after 22 h. Both preparation and storage haemolysis were lower in 0.5CPD blood processed into RAS-2-suspended RBC than in CPD blood processed into SAGM-suspended cells. The possibility of adding glucose to the red cells via the primary anticoagulant instead of the additive solution was tested. The glucose concentration had to be increased to three times that in normal CPD to supply the red cells with sufficient glucose for 6-7 weeks of storage. However, this caused increased haemolysis, particularly after prolonged hold of the whole blood at ambient temperature before component preparation. The results therefore indicate that the glucose supply should be in the additive solution. Less citric acid in the 0.5CPD anticoagulant, an increase in intracellular pH on addition of the new additive solution and supply of phosphate seem to be major factors in explaining the effects. The new combination of anticoagulant and red-cell additive solution is a clear improvement for blood component preparation and storage.