WASHINGTON - For critically ill patients, transfusing fresher blood didn't translate to better outcomes, researchers said here.
In a single-center retrospective study, patients had the same overall rates of transfusion complications and other morbidities including length of ICU and hospital stays whether they were given red blood cells that were less than 8 days old, or more than two weeks old, according to Leanne Clifford, BM, of the Mayo Clinic in Rochester, Minn., and colleagues.
"We found a lack of evidence to say that older blood is associated with worse outcomes," Clifford reported during a late-breaking abstract session at the American Society of Anesthesiologists meeting.
Some work has shown that using older stores of blood may be tied to worse outcomes, although the literature is not definitive, Clifford said. Indeed, a study published last week in the Journal of the American Medical Association found that fresh blood didn't improve outcomes for premature infants.
To explore the question, Clifford and her colleagues conducted a retrospective study at their facility that compared 99 patients who received fresh cells with 99 controls. Participants were matched on the number of blood units transfused, the number of leukoreduced units, age, admission source, and primary body system affected.
They looked only at blood that was either less than 8 days old or more than 14 days old because a number of other studies had used those parameters.
Overall, they found no differences in adverse effects whether the blood was fresh or old.
Patients had the same rates of overall transfusion complications (1% in fresh, 2% in old) and overall morbidity was comparable between groups.
There were also had similar lengths of stay in the ICU (1.8 days versus 1.6) and in the hospital (8.6 days versus 8).
Clifford said her team did see more nosocomial infections with transfusions of fresh red blood cells (9.1% versus 2%), and mortality also appeared higher in the fresh blood group (20.2% versus 9.1%).
But she said these findings are likely due to chance given the small sample size of the study, and concluded that using older blood stores doesn't appear to have any impact on outcomes in critically ill patients.
Joel Zivot, MD, of Emory University in Atlanta, who moderated the session during which the findings were presented, said the study poses a "timely and important question," although he cautioned that future studies would need to look at the exact time the transfusion occurred.
A problem with ICU outcomes, he said, is that they depend on how many days the patient has been in the unit. For instance, a transfusion occurring on the first day may be more critical than one occurring after a few days, he said.
"This is the beginning," of research into this issue, he said. "It doesn't answer the question definitively. There is more work that needs to be done on this."
Source: Med Page Today http://www.medpagetoday.com/MeetingCoverage/AdditionalMeetings/35306?utm_content=&utm_medium=email&utm_campaign=DailyHeadlines&utm_source=WC&xid=NL_DHE_2012-10-15&eun=g514381d0r&userid=514381&[email protected]&mu_id=
Secondary Source: The American Society of Anesthesiologists Meeting: Clifford L, et al "Transfusion of aged red blood cells has no impact on the outcomes of critially ill patients" ASA Meeting 2012; Abstract LBC04