Twelve-week RBC storage.

BACKGROUND: Better storage can improve RBC availability and safety. Optimizing RBC ATP production and minimizing hemolysis has allowed progressively longer storage. STUDY DESIGN AND METHODS: In the first study, 24 units of packed CPD RBCs were pooled in groups of four, realiquoted, and added to 300 mL of one of four variants of experimental additive solution 76 (EAS-76) containing 45, 40, 35, or 30 mEq per L NaCl. Units were sampled weekly for 12 weeks for morphologic and biochemical measures. In the second study, 10 volunteers donated 2 units of RBCs for a crossover comparison of Tc/Cr 24-hour in vivo recovery of 6-week storage in AS-1 versus 12-week storage in EAS-76 variant 6 (EAS-76v6) having 30 mEq per L NaCl. RESULTS: RBCs stored in the lower salt variants of EAS-76 had higher concentrations of RBC ATP with less hemolysis and microvesiculation. RBC 2,3 DPG was preserved for two weeks. RBCs stored for 12 weeks in EAS-76v6 exhibited 78 +/- 4 percent 24-hour in vivo recovery. CONCLUSIONS: It is possible to store RBCs for 12 weeks with acceptable recovery and 0.6 percent hemolysis and with normal 2,3 DPG concentrations for 2 weeks.

Alkaline CPD and the preservation of RBC 2,3-DPG.

BACKGROUND: Concentrations of 2,3-DPG decline rapidly in the first week of RBC storage because of the low pH of conventional storage solutions. Alkaline additive solutions, which can preserve RBCs for up to 11 weeks, still do not preserve 2,3-DPG because the starting pH is below 7.2. STUDY DESIGN AND METHODS: Alkaline CPD (pH=8.7) was made with trisodium citrate, dextrose, and disodium phosphate. Twelve units of whole blood were collected into heparin and pooled in groups of four units. Each pool was then aliquoted into four units; 63 mL of CPD with pH 5.7, 6.5, 7.5, or 8.7 was added to one unit of each pool, and 300 mL of the alkaline experimental additive solution-76 was added. In Study 2, 12 units were collected into alkaline CPD, pooled in groups of four, aliquoted as described, and stored in four variants of experimental additive solution-76 containing 0, 9, 18, and 27 mM of disodium phosphate. RBC ATP and 2,3-DPG concentrations, intracellular and extracellular pH and phosphate concentrations, hemolysis, and other measures of RBC metabolism and function were measured weekly. RESULTS: RBCs stored in more alkaline conditions made 2,3-DPG, but at the expense of ATP. Concentrations of 2,3-DPG decreased after 2 weeks storage, but ATP concentrations never fully recovered. Providing more phosphate both increased the duration of 2,3-DPG persistence and raised ATP concentrations in the later stages of storage. CONCLUSIONS: Maintaining both 2,3-DPG and ATP requires both high pH and high concentrations of phosphate.