The role of electrolytes and pH in RBC ASs

BACKGROUND: Experimental additive solutions (EASs) containing saline, adeni ne, glucose, mannitol and disodium phosphate can support RBCs for 9 or 10 w eeks if used in 200- or 300-mL volumes, The effects of variations in the el ectrolyte composition and volume of EASs were explored. STUDY DESIGN AND METHODS: In three four-arm studies, 24 RBC units were pool ed in groups of 4 and realiquoted as test units to ensure that all donors w ere equally represented in each study arm. In Study 1, units were stored fo r 11 weeks in EAS containing 0, 10, 20, or 30 mmol per L of sodium bicarbon ate. In Study 2, units were stored for 9 weeks in EAS containing 26, 50, 10 0, or 150 mmol per L of sodium chloride. In Study 3, units were stored in 1 00 or 200 mL of AS-3 or EAS-61. RBC ATP concentrations and hemolysis were m easured weekly. RESULTS: Increasing the sodium bicarbonate content of EASs increased the pH throughout storage and increased RBC ATP concentrations in the later phase s of storage, but it had no effect on hemolysis. Increased sodium chloride content of EASs led to lower RBC ATP concentrations and increased hemolysis . In EAS-61, RBC ATP concentrations were increased throughout storage, and hemolysis was lower than that of RBCs stored in AS-3. CONCLUSION: RBC ATP synthesis is highly dependent on the pH of the AS. Hemo lysis is affected by the salt content and volume of the AS.