Refrigerated Platelets for the Treatment of Acute Bleeding: a Review of the Literature and Reexamination of Current Standards

This review is a synopsis of the decisions that shaped global policy on platelet (PLT) storage temperature and a focused appraisal of the literature on which those discussions were based. We hypothesize that choices were centered on optimization of preventive PLT transfusion strategies, possibly to the detriment of the therapeutic needs of acutely bleeding patients. Refrigerated PLTs are a better hemostatic product, and they are safer in that they are less prone to bacterial contamination. They were abandoned during the 1970s because of the belief that clinically effective PLTs should both be hemostatically functional and survive in circulation for several days as indicated for prophylactic transfusion; however, clinical practice may be changing. Data from two randomized controlled trials bring into question the concept that stable autologous stem cell transplant patients with hypoproliferative thrombocytopenia should continue to receive prophylactic transfusions. At the same time, new findings regarding the efficacy of cold PLTs and their potential role in treating acute bleeding have revived the debate regarding optimal PLT storage temperature. In summary, a ‘‘one-size-fits-all’’ strategy for PLT storage may not be adequate, and a reexamination of whether cold-stored PLTs should be offered as a widely available therapeutic product may be indicated. KEYWORDS—Cold platelets, severe hemorrhage, acute hemorrhage, hypoproliferative thrombocytopenia, trauma, platelet storage temperature, damage control resuscitation, massive transfusion protocols ABBREVIATIONS—PLT V platelet; 4C-PLTs V refrigerated (4-C)-stored platelets; RT V room temperature; RT-PLTs V room temperature (22-C)Ystored platelets; CFRV Code of Federal Regulations sections; RCTV randomized controlled trial COLD VERSUS ROOM TEMPERATURE STORAGE OF PLATELETS FOR THE TREATMENT OF ACUTE BLEEDING Platelet (PLT) transfusion is associated with improved clinical outcomes in acutely bleeding trauma patients (1Y9). Despite common beliefs to the contrary, PLTs are available in whole-blood products; they can also be prepared as whole bloodYderived concentrates, as buffy coat preparations, or as apheresis units. Currently, unlike red cell products that are stored under refrigeration, PLT units are stored at room temperature (RT) (20-CY24-C) with constant agitation for 5 days (7 days in some European countries) to maximize recovery and survival in vivo following transfusion, because refrigerated PLTs are cleared more rapidly from circulation (10). Platelets participate in immunomodulation, maintenance and repair of vessel structures, and, their best-known function, clot formation. Prevention of bleeding requires longer circulation times (survival), whereas hemorrhage control requires initiation of the clot (activation), which removes the PLT from circulation. Increasing PLT circulating time reduces the frequency of prophylactic PLT transfusion and thus the risk of alloimmunization in patients with hypoproliferative thrombocytopenia, a population that is primarily made up of patients receiving chemotherapy. Blood providers adopted RT-stored PLTs (RT-PLTs) because most civilian PLTs are used by patients with hypoproliferative thrombocytopenia; split inventories pose logistical problems for transfusion services, and providers believe that RT storage meets the needs of patients with acute postsurgical or traumatic bleeding. Furthermore, focusing on PLT use in cancer therapy, regulators adopted PLT in vivo circulation time as the primary metric of PLT function, instead of other parameters such as adhesion, aggregation, or contribution to clot strength. Unfortunately, the switch to RT-PLTs came at the cost of increased risk of bacterial contamination and decreased hemostatic function compared with cold storage (0-CY6-C) (11Y16). Refrigerated PLTs (4C-PLTs) have been reported to reduce blood loss due to acute hemorrhage, are less conducive to bacterial growth, and were the standard of care until the mid-1980s. 51 SHOCK, Vol. 41, Supplement 1, pp. 51Y53, 2014 Address reprint requests to Andrew P. Cap, MD, PhD, FACP, Blood Research Program, US Army Institute of Surgical Research, Fort Sam Houston, TX 78234. E-mail: [email protected]. The authors declare that they have no conflicts of interest relevant to this article. The opinions or assertions contained herein are the private views of the author and are not to be construed as official or as reflecting the views of the Department of the Army or the Department of Defense. DOI: 10.1097/SHK.0000000000000078 Copyright 2014 by the Shock Society Copyright © 2014 by the Shock Society. Unauthorized reproduction of this article is prohibited. 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