Objective

Transfusion of RBC during cardiac surgery associates with adverse clinical outcomes, and is linked with ‘storage lesion’ (SL). The SL is characterised by a) the accumulation of metabolites in the RBC supernatant such as free hgb and microparticles, and b) changes in the stored erythrocytes such as depletion of adenosine triphosphate (ATP) and 2, 3-diphosphoglycerate (DPG). We compare 1) storage in the hypotonic additive solution AS7, 2) washing RBC, or 3) rejuvenation (REJ) to reduce the SL.

Methods

Leukoreduced RBC were manufactured from 5 units of whole blood that had been pooled and split into identical units on each of 6 occasions and stored in SAGM or AS7 for 20 days. RBC were then washed using a Haemonetics ACP215 (SAGM or AS7), rejuvenated with Rejuvesol and washed (SAGM units only, Citra labs In, USA) or left untreated in either SAGM or AS7. Samples were analysed immediately and 1, 2, 5 and 14 days after washing.

Results

Lactate, K+ and microparticle levels were similar in AS7 and SAGM, and were removed by washing/REJ. RBC ATP levels were restored by washing and to a greater extent by REJ. ATP levels returned to the original after 5 days. REJ or storage in AS7 improved deformability and resistance to osmotic stress as compared to SAGM storage or washing. Only REJ restored 2,3-DPG levels, which remained stable for the first 2 days. Free hgb release was lower in units stored in AS-7 and was prevented by REJ.

Conclusion

ATP levels were partially restored following washing and storage in SAGM, and to a greater extent AS-7, but as expected maximal effect was seen with rejuvenation. Storage in AS-7 alone reduced free haemaglobin levels and rejuvenation partially attenuated free haemaglobin release following washing in AS-7 or SAGM. These data suggest that these interventions might attenuate the storage lesion of red cells compared with storage of red cells in SAGM.