Evaluation of a potassium removal filter on irradiated red cells stored in SAGM

Abstract

Background and objectives: Irradiation of red cell concentrates RCCs) can lead to well-documented elevated extracellular potassium concentrations. Transfusion of these products has the potential, if given as a massive/rapid transfusion, to lead to transient hyperkalemia. A potassium absorption filter (PAF) has recently been developed and has been proven to effectively remove excess K+. However, data are lacking on the red cell quality parameters over storage after irradiation. Methods: Thirty RCCs were pooled and split into 3 groups of 10. All RCCs were irradiated on day 14 and filtered on day 28 (group 1 control), day 15 (group 2) or day 17 (group 3). Pre-irradiation, pre- and post-filtration and day 28 samples were taken for each study. Standard red cell quality parameters were measured over storage at the above time points. Results: Losses for haemoglobin, haematocrit and volume were minimal after filtration with all units containing >40g Hgbunit-1. Statistically, significant differences were observed for K+ and Na+ levels in groups filtered at either 24 or 72h post-irradiation, and this was observed directly after filtration and remained by day 28. Filtration had no significant impact on any other parameters measured. Conclusions: PAF effectively removed supernatant potassium (93%) from all RCC units. Early removal of K+ at either day 15 or 17 on RCCs subsequently stored to day 28 had no measurable effect on red cell quality, suggesting this may be a useful device to ensure further safety for at-risk immunocompromised patient groups requiring irradiated RCCs.