High-dose radiation exposure of cold-stored whole blood does not affect hemostatic function.

BACKGROUND: Whole blood (WB) transfusion is routinely used to resuscitate severely injured military trauma patients. Blood can be stored refrigerated while still maintaining reasonable function but is susceptible to environmental influences, including radiation exposure. Immune-compromised patients are transfused with irradiated blood to inactivate donor lymphocyte function (25 Gy per Association for the Advancement of Blood and Biotherapies [AARB] standard 5.7.3.2). However, there is limited information on function of WB exposed to high radiation doses. OBJECTIVE: This study aimed to determine if stored irradiated WB still retains function. This will be important if the stored blood supply is exposed to radiation in a combat situation or mass casualty incident when the need for blood will be high. METHODS: Whole blood collected from healthy donors was irradiated at 0, 25, or 75 Gy and stored at 4°C. Blood cell count, blood gas chemistry, thromboelastometry, platelet aggregation, and reactive oxygen species were measured before irradiation and at 1, 7, and 14 days of storage. Irradiated WB was compared with nonirradiated WB controls. RESULTS: Irradiated WB stored for up to 14 days was not significantly different than nonirradiated WB in most of the parameters measured. Stored blood showed expected changes associated with functional decline at longer storage times, but irradiation did not hasten the decline. There was a significant change in potassium and sodium ion concentrations after irradiation, but the functional relevance is not clear. CONCLUSION: High-dose irradiation had little effect on stored WB. Although there were changes in plasma sodium and potassium levels, there was little to no effect on hemostasis and blood cell viability. This suggests that stored blood subjected to a radiation event generating at least a dose of 75 Gy is still suitable for transfusion, which could be particularly important in the event of a mass casualty event where a large amount of blood is needed.

Evaluation of adenosine, lidocaine, and magnesium for enhancement of platelet function during storage.

BACKGROUND: The combination of adenosine, lidocaine, and magnesium (Mg2+) (ALM) has demonstrated cardioprotective and resuscitative properties in models of cardiac arrest and hemorrhagic shock that are linked to reduction of metabolic demand. Platelets play a key role in resuscitation strategies for ATC but suffer from loss of function following storage in part owing to mitochondrial exhaustion. This study evaluates whether ALM also demonstrates protective properties in stored platelet preparations. METHODS: Platelets were tested at (baseline, Day 5, Day 10, and Day 15) at 22°C (room temperature) or 4°C in 100% plasma and platelet additive solution. Adenosine, lidocaine, and magnesium treatment or its individual components (A, L, M, or combinations) were added directly to the minibags at baseline for storage. Measurements consisted of blood gas and chemistry analyses, thromboelastography, impedance aggregometry, and flow cytometry. RESULTS: Blood gas and cell analysis, as well as flow cytometry measures, demonstrated only differences between temperature groups starting at Day 5 (p < 0.05) and no differences between treatment groups. Aggregation response to collagen (A only, M only, and ALM high dose) and thrombin receptor activation peptide (A + M, and ALM high dose) was significantly greater at Day 5 compared to respective 4°C (100% plasma) controls (p < 0.05). Thromboelastography analysis revealed significant preservation of all measures (reaction time, maximum amplitude, and angle) at Day 15 for 4°C-stored samples in 100% plasma in both controls (no ALM) and ALM treatment compared to room temperature (p < 0.05); no differences were observed between the ALM and control groups. CONCLUSIONS: The mechanism of ALM's protective effect remains unclear; key cellular functions may be required to provide protection. In this study, improvements in collagen and thrombin receptor activation peptide aggregation were seen when compared to 4°C-stored plasma samples although no improvements were seen when compared to 4°C-stored platelet additive solution platelets. LEVEL OF EVIDENCE: Therapeutic/care management, level II.