Assessment of Storage Related Haematological and Biochemical Changes in Blood Units
Red blood cells are still the most widely transfused blood component worldwide and their story is intimately entwined with the history of transfusion medicine and the changes in the collection and storage of blood.1,2 At present, the most widely used protocol for the storage of red blood cells (for up to 42 days) is the collection of blood into anticoagulant solutions (typically citrate-dextrose-phosphate); red cell concentrates are prepared by the removal of plasma and, in some cases, also leukoreduction. The product is stored at 4 ± 2° C in a slightly hypertonic additive solution, generally SAGM (sodium, adenine, glucose, mannitol, 376 mOsm/L).1 The British obstetrician, Braxton Hicks in 1868, experimented with a solution of phosphate of soda, but this also proved toxic. Richard Lewinsohn, in 1915, of the Mount Sinai Hospital in New York is credited with introducing sodium citrate into clinical practice as an anticoagulant.3 In fact, a 1% solution of sodium citrate was already widely used in laboratories as an anticoagulant. This high concentration was toxic to humans but, as Lewinsohn himself recalled, `Nobody had ever followed the simple thought of carrying out experiments to ascertain whether a much smaller dose might not be sufficient’ for use as an anticoagulant.
