BAD
BLOOD
Is the Debate Over Stored Red Blood
Cells Still Relevant?
With age comes wisdom, the saying goes,
unless we are talking about red blood cells
(RBCs). Then with age comes the theoretical risk of a lack of ability to deliver
oxygen, a potential failure to traverse microcirculation, and a slew of biomechanical differences that may affect outcomes
after transfusion.
Still, each year, thousands of people in
the United States receive a blood transfusion. It would be impossible for each one
of these patients to get the freshest RBCs
available.
The U.S. Food and Drug Administration regulations state that RBCs with additive solutions can be banked for up to 42
days and still be considered usable. That’s
good news for U.S. patients who require
about 36,000 units of RBC daily, either
because they are undergoing an operation
or an emergency procedure, receiving a
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ASH Clinical News
new organ, or being treated for cancer and
other diseases that may compromise bone
marrow function.
To maximize RBC supplies, blood
banks generally dispense on a first-in,
first-out basis, the way milk is rotated in
convenience store refrigerators, working
off the assumption that blood stored up
to 42 days will degrade to some extent,
but that blood stored for this long is not
inherently harmful.
“We do know that a number of changes
occur in red cells while they are stored
in added solution over the 42-day limit
– these are morphological, biochemical,
and physiologic changes,” explained John
Roback, MD, PhD, of the Emory University Blood Bank in Atlanta, Georgia. “The
biggest concern that patients and physicians have is whether older red cells are as
efficacious as fresh red cells, or if they may
actually be deleterious.”
But if old blood loses its efficacy and
raises safety concerns, and managing
supplies means storing RBCs and using
these banked supplies in transfusions, he
asked, “Where does that leave clinicians
who need to waste as little of this precious
commodity as possible?”
In a 2013 ASH Hematology paper,
James Zimring, MD, PhD, of Puget
Sound Blood Center Research Institute
in Seattle, Washington, laid out the
central point in the fresh versus stored
blood for transfusion debate: “The
answer to the question of whether there
is a difference between fresh and old
blood seems to be an unequivocal ‘yes.’
… On the contrary, the question of ‘does
it matter’ remains unclear and is likely
to remain so for some time.”1
So, does age of transfused RBCs matter?
February 2016