Impact of a rapid blood warmer on the quality and function of cold-stored platelets.

Background and objectives: Pre-hospital critical care faces challenges in carrying platelet concentrates (PC). Cold-stored platelets (CSP) may offer improved haemostatic function over room temperature platelets. Rapid warming of blood products is crucial for hypothermic trauma patients. This study evaluates whether the°M Warmer System (°MEQU, Copenhagen), used for red cells and intravenous thrombin receptor activator peptide 6 fluids, affects CSP functionality compared to a standard giving set.

Materials and methods: Buffy coat-derived platelets, in a platelet additive solution to plasma ratio of approximately 65:35, were stored at 4 ± 2°C without agitation for 6 days. A baseline measurement was taken on Day 2. On Day 6, a 'pre-sample' was taken; then CSP were either infused through the°MEQU or a standard transfusion-giving set. Platelet function was assessed by aggregation and thromboelastography (TEG). Platelet activation was assessed by CD62P expression, Annexin V binding, microparticle concentration and soluble CD62P concentration. Ten replicates were completed.

Results: Neither aggregation nor TEG showed significant differences between PC infused through the standard set or the rapid blood warmer. Soluble CD62P levels were significantly higher in both the standard giving set (26.7 ± 6.4 ng/mL) and rapid blood warmer (25.9 ± 5.1 ng/mL) compared to the pre-sample (18.8 ± 4.8 ng/mL), with no significant difference between the groups.

Conclusion: The°MEQU did not detrimentally affect platelet quality and functionality compared to a standard giving set, suggesting the feasibility for a CSP clinical trial in the pre-hospital environment.