In a report published online in the journal Anesthesia & Analgesia, the Johns Hopkins investigators say red cells in blood stored that long gradually lose the flexibility required to squeeze through the body's smallest capillaries to deliver oxygen to tissue. Moreover, they say, that capacity is not regained after transfusion into patients during or after surgery.
"There's more and more information telling us that the shelf life of blood may not be six weeks, which is what the blood banks consider standard," says study leader Steven M. Frank, M.D., an associate professor of anesthesiology and critical care medicine at the Johns Hopkins University School of Medicine. "If I were having surgery tomorrow, I'd want the freshest blood they could find."
Frank acknowledges that blood banks do not have enough fresh blood for everybody, and that shorter storage periods would result in diminished inventory. But he says that the current practice of transfusing blood stored up to six weeks may need to be reconsidered.
One previous, large study published in the New England Journal of Medicine has already shown that cardiac surgery patients who received blood stored longer than three weeks were almost twice as likely to die as patients who got blood that had been stored for just 10 days.
For the new study, Frank and his colleagues enrolled 16 patients scheduled to have spinal fusion surgery, a type of operation that typically requires blood transfusions. Six of the patients received five or more units of blood, while 10 needed three or fewer units. The researchers drew samples from every bag of blood used — 53 in total — and measured the flexibility of the red blood cells. What they found is that blood older than 3 weeks was more likely to have less flexible red blood cell membranes, a condition that may make it more difficult for blood to deliver oxygen, Frank says.
The team also took blood samples from patients in the three days following surgery. Even though the blood cells were out of storage and back in biological environments with proper pH (acidity), electrolytes and oxygen levels, the injury to the red cells was not reversible and appeared to be permanent. The damaged blood cells would likely remain dysfunctional for their life cycle limit, which is up to 120 days, Frank says.
Frank also noted that patients in the study who got fewer units of blood had healthier red cells overall, even though the blood was just as old and showed cell damage. He says it is likely that a small amount of these problem cells make less of a difference than when a large number of damaged cells are present.
According to the research report, the average age of the blood given in the study was more than 3 weeks. Only three samples in the study were 2 weeks old or less. One reason for the lack of availability of fresher bloods for adults, Frank says, is the routine practice of giving pediatric patients priority for the freshest units.
In fact, he notes, blood banks dispense the oldest blood first so that it doesn't exceed its shelf life before it can be used. "As a colleague said, it's like how they sell milk in the grocery store — they put the oldest cartons out front so they can sell them before they expire," Frank says.
Two large randomized controlled studies, one at many centers across the United States, including Johns Hopkins, and one in Canada, are under way to determine the relative safety of older versus newer blood, and the results are expected next year. Frank says blood banks need to be prepared to change practice if those studies show that a six-week shelf life for blood is just too long.
The study was supported in part by the National Institutes of Health's National Institute on Aging (R01 AG021523) and National Heart, Lung, and Blood Institute (R01 HL092259-01).
Other Johns Hopkins researchers involved in the study include Bagrat Abazyan, M.D.; Masahiro Ono, M.D.; Charles W. Hogue, M.D.; David B. Cohen, M.D., M.P.H.; Daniel E. Berkowitz, M.D.; Paul M. Ness, M.D.; and Viachaslau M. Barodka, M.D.
Ness has consulted for Terumo BCT and Fenwal Labs, both companies involved with blood storage. Nothing in this study directly benefits these companies. The terms of these arrangements are being managed by The Johns Hopkins University in accordance with its conflict of interest policies.
For more information:
Stephanie Desmon | EurekAlert!
Innovative genetic tests for children with developmental disorders and epilepsy
11.07.2018 | Christian-Albrechts-Universität zu Kiel
Oxygen loss in the coastal Baltic Sea is “unprecedentedly severe”
05.07.2018 | European Geosciences Union
A new manufacturing technique uses a process similar to newspaper printing to form smoother and more flexible metals for making ultrafast electronic devices.
The low-cost process, developed by Purdue University researchers, combines tools already used in industry for manufacturing metals on a large scale, but uses...
For the first time ever, scientists have determined the cosmic origin of highest-energy neutrinos. A research group led by IceCube scientist Elisa Resconi, spokesperson of the Collaborative Research Center SFB1258 at the Technical University of Munich (TUM), provides an important piece of evidence that the particles detected by the IceCube neutrino telescope at the South Pole originate from a galaxy four billion light-years away from Earth.
To rule out other origins with certainty, the team led by neutrino physicist Elisa Resconi from the Technical University of Munich and multi-wavelength...
For the first time a team of researchers have discovered two different phases of magnetic skyrmions in a single material. Physicists of the Technical Universities of Munich and Dresden and the University of Cologne can now better study and understand the properties of these magnetic structures, which are important for both basic research and applications.
Whirlpools are an everyday experience in a bath tub: When the water is drained a circular vortex is formed. Typically, such whirls are rather stable. Similar...
Physicists working with Roland Wester at the University of Innsbruck have investigated if and how chemical reactions can be influenced by targeted vibrational excitation of the reactants. They were able to demonstrate that excitation with a laser beam does not affect the efficiency of a chemical exchange reaction and that the excited molecular group acts only as a spectator in the reaction.
A frequently used reaction in organic chemistry is nucleophilic substitution. It plays, for example, an important role in in the synthesis of new chemical...
Optical spectroscopy allows investigating the energy structure and dynamic properties of complex quantum systems. Researchers from the University of Würzburg present two new approaches of coherent two-dimensional spectroscopy.
"Put an excitation into the system and observe how it evolves." According to physicist Professor Tobias Brixner, this is the credo of optical spectroscopy....
13.07.2018 | Event News
12.07.2018 | Event News
03.07.2018 | Event News
20.07.2018 | Power and Electrical Engineering
20.07.2018 | Information Technology
20.07.2018 | Materials Sciences