(RxWiki News) United States blood banks deploy rigid testing protocols and are generally considered safe. However, the breakdown of red blood cells in stored blood may cause complications for those receiving transfusions.
A research study says blood stored longer than 39 days could reduce blood flow and damage vital tissues if transfused into a patient. Federal guidelines allow for blood to be stored up to 42 days.
"Ask a nurse the age of transfusion blood before you receive it."
Dr. Mark T. Gladwin, senior investigator, chief of the division of pulmonary, allergy and critical care medicine at the Pittsburgh School of Medicine, and director of Pitt’s Vascular Medicine Institute, said that when blood is stored for an extended period, cells can break down and release their contents, including molecules of hemoglobin and red blood cell microparticles.
University of Pittsburgh School of Medicine and Wake Forest University researchers found that transfusing blood days before it must be thrown out is linked to an increased risk of infection, kidney, lung or multiple organ failure, and death. This was especially true of vulnerable patients such as the elderly.
After old blood is transfused to a patient, the hemoglobin and microparticles destroy nitrogen oxide. Nitrogen oxide helps keep blood vessels open to ensure blood flow. A search for nitrogen oxide ultimately causes blood vessels to constrict. This prevents tissues and organs from getting adequate oxygen.
During the study, researchers noticed that stored human blood accumulates loose hemoglobin that is no longer contained in the damaged cells. Those products of the breakdown process reacted with nitrogen oxide about 1,000 times faster than intact red blood cells.
Investigators hope to use the research to help make blood transfusions safer. They are researching several possibilities including restoring nitric oxide, better preserving blood, or developing a method to scavenge the loose hemoglobin.
Additional research also is being conducted to evaluate the safety of blood stored beyond 14 days.
The research was published in Circulation.