Age of transfused blood in critically ill adult trauma patients: a prespecified nested analysis of the Age of Blood Evaluation randomized trial.

Background: Blood transfusion is common in the resuscitation of patients with traumatic injury. However, the clinical impact of the length of storage of transfused blood is unclear in this population.
Study Design and Methods: We undertook a prespecified nested analysis of 372 trauma victims of the 2510 critically ill patients from 64 centers treated as part of the Age of Blood Evaluation (ABLE) randomized controlled trial. Patients were randomized according to their trauma status to receive either a transfusion of fresh blood stored not more than 7 days or standard-issue blood. Our primary outcome was 90-day all-cause mortality.
Results: Overall, 186 trauma patients received fresh blood and 186 received standard-issue blood. Adherence to transfusion protocol was 94% (915/971) for all fresh blood transfused and 100% (753/753) for all standard-issue blood transfused. Mean ± SD blood storage duration was 5.6 ± 3.8 days in the fresh group and 22.7 ± 8.4 days in the standard-issue group (p < 0.001). Ninety-day mortality in the fresh group was 21% (38/185), compared to 16% (29/184) in the standard-issue group, with an unadjusted absolute risk difference of 5% (95% confidence interval [CI], -3.1 to 12.6) and an adjusted absolute risk difference of 2% (95% CI, -3.5 to 6.8).
Conclusion: In critically ill trauma patients, transfusion of fresh blood did not decrease 90-day mortality or secondary outcomes, a finding similar to the overall population of the ABLE trial.
(© 2018 AABB.)