Storage of red blood cells: new approaches.

Longer red blood cell (RBC) storage can improve blood logistics, increase the usefulness of autologous blood storage, and reduce donor exposure in neonatal intensive care. Better RBC storage can prevent membrane loss and preserve the secretion of adenosine 5'-triphosphate (ATP) in response to deformation. Better RBC storage may also reduce the formation of proinflammatory membrane breakdown products that lead to transfusion-related acute lung injury and the systemic inflammatory response syndrome. To improve RBC storage, the authors have attempted to maximize the production of ATP by the manipulation of pH and to minimize membrane loss through the use of membrane protectants and the manipulation of tonicity. Increasing the initial storage pH led to successively higher RBC ATP concentrations until pH 7.2 was reached, when the synthesis of 2,3-diphophoglycerate was initiated at the expense of ATP. Synthesis of ATP could be maintained by buffering the fall of pH with increased storage solution volume or the addition of bicarbonate. Maintaining RBC ATP turns out to be an important way of preventing membrane microvesiculation or blebbing, as does the manipulation of tonicity and the addition of mannitol. These experiments show that it is possible to store RBC in experimental additive solutions containing only saline, adenine, glucose, mannitol, sodium bicarbonate, and disodium phosphate for 11 weeks or longer with little loss of membrane and high in vivo recovery.