Does stored blood lose effectiveness after two weeks?

[Mk]

http://www.newscientist.com/channel...or-transfusions.html?feedId=online-news_rss20

Doctors at the Cleveland Clinic in Ohio have found that patients who receive blood that is more than 14 days old are nearly two-thirds more likely to die than those who get newer blood.

The survey of more than 9000 heart surgery patients also suggests that recipients of older blood are more at risk from blood poisoning and organ failure.

http://content.nejm.org/cgi/content/full/358/12/1229
Oh dear.

Discuss.

 

[scorpa]

The longer red cells are stored the more potassium (and everything else you find inside a red cell) will leak out of the cell and accumulate in the plasma or additive solution they are stored in. This puts you at risk for an immediate non hemolytic transfusion reaction, in this case due to potassium toxicity. This is a huge thing for newborns, they are so senstitive to this that only fresh units can be used in their case.

Plus red cells only have a lifespan of 120 days in the body, this is less when it is in a bag (depending on storage methods this can be prolonged). The longer you wait to transfuse the cells the more the cell membranes will lose integrity, increasing the chance that you will be transfusing hemolyzed cells into the patient, which feeds back to the risk of red cell components leaking out.