Characterization of biochemical changes occurring during storage of red cells. Comparative studies with CPD and CPDA-1 anticoagulant-preservative solutions.

Citrate-phosphate-dextrose-adenine (CPDA-1), containing 0.25 mM adenine (final concentration) and 25 percent more glucose than citrate-phosphate-dextrose (CPD), has extended the allowable storage time for red cells to 35 days. Studies were conducted to understand better the characteristics of stored CPDA-1 red cells in relation to the properties of stored CPD red cells. Units with hematocrits near 80 percent showed the following: First, adenosine triphosphate (ATP) and total adenine nucleotide levels of red cells stored with CPDA-1 remained essentially constant during the first 3 weeks of storage after which the levels decreased; with red cells stored with CPD, ATP, and adenine nucleotide, levels were decreased even after 1 week of storage. Second, the pattern of the fall in 2,3-diphosphoglycerate was similar in red cells stored with CPD and CPDA-1. Third, changes in plasma and red cell levels of sodium and potassium, and in plasma ammonia levels, were comparable in CPD and CPDA-1 units; changes in cation levels were most pronounced during the initial 2 weeks of storage. Fourth, hemolysis was much greater in units stored in CPDA-1 for 35 days than in units stored in CPD for 21 days. Fifth, residual glucose concentrations were adequate in units drawn in CPDA-1 and stored for 35 days. We conclude that the changes in the biochemical characteristics of units of red cells stored with CPD and CPDA-1 are similar in most instances with the notable exception of the better maintenance of adenosine triphosphate levels in red cells stored with CPDA-1.