Monday, July 25, 2011

Blood Stored Too Long May Threaten Patient Safety

THURSDAY, July 21 (HealthDay News) -- New research links medical problems caused by blood transfusion to the breakdown of red blood cells during blood storage. The findings suggest that a better way to store blood is needed.
When transfused, older blood or high amounts of blood can lead to complications, including infection, kidney and lung failure and death, said study co-author Dr. Mark T. Gladwin in a news release from Wake Forest University, which led the study.
The study examines the interaction between nitric oxide (NO) and the byproducts created as red blood cells break down over time. The researchers found that the interaction in older blood can reduce blood flow and perhaps damage tissues in the body.
"When blood sits for a while, some of the cells break down and release their contents, which include molecules of hemoglobin and red blood cell microparticles," said Gladwin, chief of the division of pulmonary, allergy and critical care medicine at the University of Pittsburgh School of Medicine. "These accumulate in the stored bag of blood and are transfused into the patient with the blood. In the bloodstream, the hemoglobin and microparticles bind to and destroy [nitric oxide], a very important molecule that is used by the body to keep blood vessels dilated for normal blood flow."
"Transfusion of stored blood is one of the most common medical therapies," said study senior author Daniel B. Kim-Shapiro, professor of physics and director of the Translational Science Center at Wake Forest University, in the news release. "For example, perhaps we can restore nitric oxide activity that is lost upon transfusion, use preservation solutions that better limit the degradation of blood cells, or develop agents that scavenge free hemoglobin."
Future studies will examine the safety of blood stored more than 14 days. Under current federal guidelines, blood can be stored for up to 42 days.
Each year in the United States more than 5 million people receive blood transfusions, according to the study.
The study is published in the journal Circulation.