Cold‐stored versus room‐temperature platelets for hemostasis in combat trauma patients

BACKGROUND: The United States military has transfused room temperature platelets (RTPs) in combat since 2004, but distribution to far-forward locations is limited. To expand access, cold-stored platelets (CSPs) were approved for 10-day storage in 2017, increased to 14 days in 2019, but clinical outcome reporting has been limited. This study assessed whether CSPs were associated with mortality in combat trauma patients when compared with RTPs. STUDY DESIGN AND METHODS: A retrospective analysis of military databases evaluated combat casualty records 2001-2023. The intervention of interest was the transfusion of at least one unit of CSPs under a 10-day or 14-day expiration protocol. The outcome of interest was mortality at discharge. Logistic regression compared the treatment groups with a control cohort that only received RTPs. RESULTS: Over the study period, 159 patients received 341 CSP units. Records were located for 124 patients: 57 received 10-day CSPs and 67 received 14-day CSPs. Overall mortality was 16.1% in the CSP cohort and 13.9% in the control group. Exposure to 10-day CSPs (adjOR = 0.39 [0.18-0.86]; p = .02) or 14-day CSPs (adjOR = 0.41 [0.20-0.83]; p = .01) was associated with decreased mortality. The outdating rate was 75.2% for RTPs and 93.4% for CSPs. CONCLUSION: CSPs up to 14 days old appear non-inferior to 5-day RTPs. CSP age at transfusion trended toward the end of shelf life, indicating demand previously unmet by RTPs. Patients do well when they receive platelets as close to injury as possible; CSPs better facilitate this intervention in remote locations. CSPs should be further evaluated for use in a broader range of emergent transfusion scenarios.