Platelet concentrates (PC) are essential for the haemostatic management and prevention of bleeding in trauma patients.  PCs intended for transfusion are stored in the blood centre at room temperature (RT), with total shelf life of 5 days. The limited storage duration for the PC results in uneven inventory which on one-hand may lead to shortage during increased requirement or can result in increased wastage due to outdating PC. Cryopreservation of surplus whole blood-derived PC using dimethyl sulfoxide (DMSO) offers a promising solution to this problem, by extending the shelf life up to 2 years. This can be especially useful during trauma, war, disasters, seasonal epidemics (such as dengue), etc.  

Although, several in-vivo studies have been conducted to assess its safety and efficacy and has been shown to be non-inferior to fresh PC. As result of which many countries have adopted use of cryopreserved platelets for clinical use. Since, no studies have been conducted in the Indian context, where the shelf life of PC is limited to 5 days. We intend to evaluate the morphology, number and function of the cryopreserved platelets using cellular indices, flowcytometric markers for its activation and thromboelastometric response, following its transfusion in thrombocytopenic trauma patients.  

Dept of transfusion medicine: PC shall be prepared from whole blood collected from blood donors. Surplus PCs will then be pooled together on day 4 of storage, followed by splitting into equal halves to ensure that the control and intervention group are similar in terms of baseline platelet counts, sterility and platelet activation markers, measured using flowcytometry. After this the control group will be stored and issued as per the current standards. Simultaneously the PC in the intervention group, will be treated with DMSO (to achieve final concentration of 5-6% DMSO) under aseptic conditions. The procedure will be performed under strict aseptic conditions and in accordance with the protocols published in the literature. These DMSO treated PC will be stored at -80C for a minimum of 72 hours. After this the DMSO treated PC will be thawed and evaluated for the platelet counts, sterility and platelet activation markers, measured using flowcytometry. This will help us in establishing the in-vitro platelet recovery and the function of the cryopreserved platelets. 

Dept of surgery and Dept of critical and intensive care: Adult trauma patients who are hemodynamically stable and require platelet transfusion prophylactically, will be enrolled in the study groups (control and intervention) after taking informed consent. A baseline sample for complete blood counts, coagulation assays, and platelet function assays (thromboelastometry) will be done, prior to PC transfusion. After transfusion (1-2 hours), the same tests (complete blood counts, coagulation assays, and platelet function assays) will be performed to evaluate the response to to the platelet transfusions. After transfusion of PCs, patients will be actively monitored next 48 hours, for any adverse reactions associated with the transfusion and any additional need for platelet transfusion will be evaluated. This will help us in establishing the in-vivo haemostatic response to the platelet transfusions.