Fresh blood not best, old Red blood cells equally safe for transfusion : NEJM

A landmark Australian research trial has found the transfusion of older stored red blood cells is safe and surprisingly, associated with fewer side effects. In the TRANSFUSE trial, researchers from the Australian and New Zealand Intensive Care Research Centre at Monash University in Melbourne led teams in 5 countries to investigate the effect of the age of transfused red blood cells on critically ill patient's outcomes.

In a study published in the New England Journal of Medicine on September 27th, the team demonstrated that fresher blood was no better than older blood. Unexpectedly 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.

Lead researcher Professor Jamie Cooper said "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".

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. Concerns regarding changes in the red blood cells for transfusion during storage, have led some countries to reduce this to 35 days, and some doctors to request fresher blood for specific patients under the belief the "fresh must be best". "Such practices can significantly reduce the availability of blood for transfusion" said Professor Cooper. "Our study shows these practices are not required and are potentially counterproductive".