Standardization of the red cell product.

Red cell products are currently sourced from whole blood and apheresis donations. Whole blood derived red cell products may show up to a two-fold variation in red cell content (potency); apheresis derived red cell products are currently more standardized to a red cell content of 180 ml and with much less variation, approximately 6%. Whole blood collections can be modified to produce a more standardized red cell content and apheresis collections can also be modified to increase variability. The advantage of a standardized red cell product lies in the greater degree of predictability of clinical outcome for any predefined recipient. This, in turn, could result in an alteration in physician prescribing practices, avoiding over-transfusion, especially in low volume recipients. An alternative would be to measure and label the potency of each red cell product, allowing some degree of recipient defined product choice by the transfusion service. The current situation where red cell products are prescribed in non-standard 'units' is outdated and unscientific.