Duration of storage is dependent on a number of factors, including the management system, supply and demand, and blood type (less common blood types, such as Type AB negative, tend to be stored longer than more common types, particularly Type O). Currently, the Food and Drug Administration (FDA) limits storage duration to a maximum of 42 days, depending on the storage system.
"Stored blood undergoes changes, meaning that transfusion of older red blood cells may result in the delivery of high concentrations of red blood cell components such as hemoglobin, free iron, and red blood cell fragments," said Colleen G. Koch, MD, MS, MBA, from the Cleveland Clinic in Ohio. "These components may contribute to adverse clinical events observed in a number of investigations."
Dr. Koch and colleagues reviewed existing literature to examine the presence of storage-related complications in patients who underwent blood transfusions. They found several studies in trauma and cardiac surgery that linked increased blood storage duration to post-injury multiple organ failure, infection, deep vein thrombosis, and hospital mortality, while other studies reported no apparent relationship between storage duration and clinical outcomes.
Several ongoing randomized controlled trials may answer more questions in the future. Meanwhile, the researchers recommend exploring changes to the current first-in, first-out process. They pointed to new models of inventory management in the retail sector that would reduce inventory shelf time in favor of just-in-time delivery of products.
"We hope our results engage others in the medical community to investigate alternative inventory management strategies that would contribute to reducing the storage age of the red cell product without adversely influencing inventory availability," said Dr. Koch.
One existing model involves blood platelet donation. Platelets expire 5 days after donation, so managing platelet inventory requires hourly monitoring and more frequent deliveries from blood collection agencies. Using these same techniques for red blood cell donations could help reduce blood storage duration to 14 days or less, according to the researchers.
"We recommend further work with inventory management to explore strategies that would optimize fresher blood for patients," said Dr. Koch. "Until results of ongoing randomized controlled trials in the area of storage duration are completed, we cannot recommend a change in the current FDA formal guidelines; however, we encourage surgeons to remain aware of the possible complications associated with red blood cell transfusion."