With blood, fresh is not best
Trials show that older stored transfusion blood delivers better outcomes than freshly harvested stuff, writes Jeff Glorfeld.
A landmark Australian research trial has found that blood, like good red wine, improves with age – at least when it’s stored for transfusion.
In a study published in the New England Journal of Medicine, researchers from the Australian and New Zealand Intensive Care Research Centre at Monash University in Melbourne led teams in five countries to investigate the effect of the age of transfused red blood cells on critically ill patients.
The trials involved 5000 intensive care patients in Australia, New Zealand, Finland, Ireland and Saudi Arabia. Analysis concluded the transfusion of older stored red blood cells is safe and, surprisingly, associated with fewer side effects.
Researchers demonstrated that fresher blood was no better than older blood. They also found fewer transfusion reactions, including fever, with the older blood; and in the most severely ill patients, the transfusion of older blood was associated with fewer deaths.
In Australia, red blood cells are stored for up to 42 days before transfusion. Routine practice in most hospitals is to allocate the oldest available compatible blood. However, concerns regarding changes in the red blood cells for transfusion during storage have led some countries to reduce this storage time to 35 days, and some doctors to request fresher blood for specific patients.
“Such practices can significantly reduce the availability of blood for transfusion,” lead researcher Jamie Cooper says. “Our study shows these practices are not required and are potentially counterproductive.”
Cooper says “older blood appears to be like a good red wine – better with some age”.
“The findings of our trial confirm that the current duration of storage of red blood cells for transfusion is both safe and optimal,” he says.