Red cells suspended in a phosphate-fortified additive: biochemical enhancement and longer storage

When compared to our current storage regime, an additive solution, with 75 mM inorganic phosphate, improved certain biochemical and morphological parameters measured in suspensions of packed red cells throughout 49 days of liquid storage. In particular, the mean ATP level of 20 donations stored with the high phosphate additive was consistently and significantly higher than in standard (n = 6) suspensions. The increased amount of inorganic phosphate and the higher pH of the new additive stimulated ATP production and provided better pH buffering than the standard solution currently in use. Although survival study results indicated adequate 24h survivals for erythrocytes stored for 42 days with the new solution, after 49 days storage, the mean 24h survival of autologous erythrocytes was only 58 +/- 7% (n = 6).