The mean time of red cell storage for a unit at transfusion is approximately 17.9 days (Department of Health and Human Services).
The maximal allowable storage duration of RBCs depends on the storage media.
AS-1, AS-3, AS-5 Are frequently used as solutions for anticoagulation so that RBCS Can be stored for up to 42 days at a temperature of 33.8-42.8°F.
During RBC storage biochemical, metabolic, structural, inflammatory, and physiologically changes occur due to the storage process.
Collectively, storage changes are referred to as the “storage lesion”.
It is common practice for hospital blood services to issue the oldest compatible red blood cell unit available for transfusion as part of routine inventory management.
The relationship between the duration of RBC storage and clinical outcomes among recipients of transfusions is not clear-cut.
Many studies have been done comparing fresher RBCS to older RBCs without definitive results.
Some studies of RBC storage associated with increased risk of mortality, pneumonia, multiple organ dysfunction while others concluded no such relationship.
RBC storage duration is primarily based on the degree of hemolysis at the end of storage at the percent of the RBCs remaining in the circulation 24 hours following transfusion.
The degree of hemolysis at the end of storage should be less than 1% and 75% of cells should remain in the circulation 24 hours following transfusion.
During red blood cell storage there is progressive decrease in intracellular 2,3 diphospoglycerate (DPG) and adenosine triphosphate with a concomitant accumulation of extracellular free hemoglobin and free iron.
As a result of a decrease in 2,3-DPG There is reduced oxygen delivery to tissues.
RBC storage leads to irreversible changes in RBC cellular membrane, including the release of microvesicles, reduced deformability and the increased possibility of occlusion of the microvasculature.
RBC storage may lead to free extracellular hemoglobin accumulation or to the accumulation in microvesicles where it may scavenge nitric oxide, and may increase circulating non-transferrin bound iron and promote inflammation.
With RBC storage there is a progressive accumulation of lactic acid, potassium and a progressive decrease in pH.
With RBC storage there is increasing accumulation of biological byproducts, cytokines, lipids, histamines, and enzymes capable of inducing febrile reactions, oxidative membrane damage or alterations in the immune system.
Despite the above alterations and metabolic changes no data exists to suggest in vivo clinical significances.
Studies on the duration of RBC storage in patients undergoing cardiac surgery, trauma or critical care are mixed and that no clear cut consistent adverse relationships exists.
Duration of blood cells storage is not associated with significant differences in the change in multiple organ dysfunction score: transfusion of RBCs stored for 10 days or less is not superior to the transfusion od RBCs stored for 21 days or more among patients undergoing complex cardiac surgery (Steiner ME et al).
Among critically ill pediatric patients, the use of fresh red blood cells did not reduce the incidence of new progressive multiple organ dysfunction syndrome (Spinella PC).