Half-Strength Citrate CPD Combined with a New Additive Solution for Improved Storage of Red Blood Cells Suitable for Clinical Use

Abstract

Currently used systems for red blood cell (RBC) collection and storage for transfusion have the disadvantage that the RBC 2,3-bisphosphoglycerate (BPG) concentration is depleted within two weeks of storage, resulting in a left-shift of the oxygen dissociation curve and a temporarily impaired capacity to deliver oxygen. We have studied the effects on red cell metabolism, morphology and in vivo recovery of 49-day storage of RBC, with collection in half-strength citrate CPD (0.5CPD) and storage in an additive solution containing citrate, adenine, mannitol, phosphate and glucose (RAS2). Traditional CPD-SAGM was used for comparison. Component preparation was performed after an initial holding period of the whole blood at ambient temperature for 8h. The BPG concentration in 0.5CPD-RAS2 RBC was 0.633±0.120 mol (mol Hb)^-1 as compared to 0.454±0.138 mol (mol Hb)^-1 in CPD-SAGM RBC which implied a decrease to 67 and 48% of normal concentration, respectively. The mean RBC BPG concentration was maintained at the initial level for 28 days in the new system but decreased to very low levels within 14 days in the controls. The total adenine nucleotides were well maintained in both systems, adenosine triphosphate slightly better in the new system. Hemolysis after 49 days was 0.35±0.21% in the new system and 0.72±0.25% in the controls (p<0.001). The morphology was better maintained in the new system (p<0.001). The 24-hour posttransfusion survival of 49-day stored RBC was 78.9±7.1%. The membrane leakage of sodium and potassium was not significantly different in the two systems. The concentration of inorganic phosphate (Pi) in the extracellular fluid of 0.5 CPD-RAS2 RBC was initially 7.1±0.8 mmol l^-1. It decreased to approximately 5.5 mmol l^-1 during the first 2 weeks of storage and then slowly increased to 9.4±0.9 mmol l^-1 on day 49. Pi in the CPD-SAGM controls was low initially but rose to 6.2±0.4 mmol l^-1 at the end of storage. The new system offers clearcut advantages as compared to traditional systems and does not seem to raise any serious clinical objections against its use even in massive transfusions.

Clinical and Laboratory Experience with Erythrocyte and Platelet Preparations from a 0.5 CPD Erythro-Sol Opti System

“…The hemolysis was lower than in traditional additive solutions such as SAGM, thus confirming earlier findings with Erythro-Sol. The glucose concentration had decreased by about 55% with a corresponding increase in lactate concentration, in agreement with earlier findings [9,12]. The concentration of ATP was normal and that of total adenylates above nor mal.…”

“…After collection of blood in an acid anticoagulant like ACD or CPD, the 2,3-DPG concentration decreases rapidly if the blood is not cooled to storage temperature; a loss of about 50% in 8 h was observed in our previous experiments [9,12]. The higher the temperature, the more quickly starts the 2,3-DPG decrease.…”

“…Rapid cooling of the blood to 20°C is a way to counteract the loss, but even then about 60% of the original 2,3-DPG content is lost within 16 h [24], thus at a rate of about 4%h. This initial loss is less rapid when the blood is collected in 0.5CPD but great individual variations are seen [12,16].…”

“…Applying 8-hour hold before component separation allows 49-day storage of the red cells at 4°C with about 80% in vivo recovery [12], Recently, these findings have been confirmed in studies showing that the initial hold of whole blood before compo nent preparation can be extended to 24 h, still with mainte nance of the already mentioned positive effects [14], In an…”

“…The use of half strength citrate CPD solution as anticoag ulant [10] and a new additive solution, provisionally named RAS2 [9,11,12] and later manufactured under the name of Erythro-Sol, improves the stability of factor VIII [10,13] in 20°C-stored whole blood, and delays considerably the nor mally rapid loss of 2,3-DPG in 4°C-stored red cells [9,12], Other advantages with the system are lower storage hemo lysis and better maintained erythrocyte viability, morphol ogy and adenine nucleotide concentration. Applying 8-hour hold before component separation allows 49-day storage of the red cells at 4°C with about 80% in vivo recovery [12], Recently, these findings have been confirmed in studies showing that the initial hold of whole blood before compo nent preparation can be extended to 24 h, still with mainte nance of the already mentioned positive effects [14], In an…”