The effect of two additive solutions on the postthaw storage of RBCs

BACKGROUND: Sterile systems for freezing and for washing thawed blood will allow the storage of RBCs for more than 24 hours after removal of the cryop rotectant glycerol. This study assessed the effect of two ASs in maintainin g deglycerolized RBCs. STUDY DESIGN AND METHODS: Twenty-four RBC units were stored for 6 days, poo led in groups of 4, realiquoted, sterilely glycerolized, and frozen. One mo nth later, the units were thawed, sterilely deglycerolized by using an auto mated system (H215; Haemonetics), and stored for 5 weeks in either 100 or 2 00 mL of AS-3 or an experimental AS (EAS-61). Sterile samples were taken we ekly for chemical and morphometric analysis. RESULTS: The glycerolization and deglycerolization process produced highly comparable RBC units, but it caused a marked reduction of RBC pH, to about 6.4 at the beginning of storage. The addition of acidic AS-3 further reduce d the pH, which in turn reduced glucose consumption, lactate formation, and RBC ATP concentrations. Alkaline EAS-61 increased these measures. Hypotoni c EAS-61 caused increased cell swelling and hemolysis, despite better RBC m orphology. CONCLUSIONS: Automation of sterile glycerolization and deglycerolization wi th the H215 works well, but the solutions should be reformulated for extend ed postthaw storage. This would best be accomplished by raising the pH of t he wash solutions by the addition of disodium phosphate or sodium bicarbona te or both, by using alkaline ASs, and by matching the osmolality of the wa sh solution and ASs.