Researchers at the Johns Hopkins University who analyzed red blood cells-RBCs in patients receiving blood through transfusion found that blood stored for transfusion, for more than three weeks could lack the ability to deliver oxygen throughout the body.
Lead researcher, Dr. Steven M. Frank, Associate Professor in Critical care Medicine and Anesthesiology at the hospital said that there is proof available which strengthens the view point that shelf-life of blood may not be six weeks which is considered safe by blood banks. He said that fresher the blood, the better.
The team enlisted sixteen patients who were to undergo spinal fusion surgery in which blood transfusion is usually required. Six patients got five units or more of blood while ten required three units or lesser. Each bag was analyzed for flexibility of RBCs.
Researchers said that RBCs in stored blood gradually loose their flexibility or ability required to push cells through the smallest capillaries in order to deliver oxygen. Blood stored for three weeks or more was likely to contain fewer flexible RBC membranes. They found that the damage caused by infusing such blood was irreversible and the problem persisted for the entire life of blood cells which lasts normally up to 120 days.
An earlier study had proved that blood stored for three weeks or more when transfused in patients who underwent cardiac surgery doubled their chances of death as compared to patients who received blood stored for not more than 10 days.
Dr. Frank observed that blood banks might not have enough fresh blood to offer for transfusion. Also, shorter storage periods could reduce stock in inventory. He said that the deficit in fresh blood could be attributed to prioritizing pediatric patients over adults for fresh units.
Sheila MacLennan who is consultant Hematologist at NHS Blood and Transplant in UK observed the findings and said that until bigger clinical trials are conducted to prove these findings, blood should not be stored for shorter time duration since this could lead to wastage of a precious resource.