The Use of Frozen Platelets for the Treatment of Bleeding

Frozen platelets have been used for the treatment of bleeding patients in military and austere settings. In addition to the advantage of a prolonged shelf life, following thawing, frozen platelets may have enhanced hemostatic capacities compared to normal stored platelets. The process of freezing and thawing leads to activation of platelets. Although there appears to be a decreased aggregation capacity compared to normal stored platelets, initiation of clotting occurs faster and thrombin-generating potential is increased with frozen platelets. There is rapid clearance of freeze-thawed platelets from the circulation, which has caused concern. However, whereas clearance of these platelets from the circulation within hours is unwanted in patients for whom a platelet transfusion is intended to correct a thrombocytopenia, it may not necessarily be harmful when administered to a bleeding patient, providing the bleeding has stopped. In this chapter, we will outline the effect of the freeze-thawing cycle on the platelet itself and on hemostatic assays, as well as on the safety and efficacy of the use of frozen platelets to stop bleeding as reported in clinical studies.