BACKGROUND Many military and civilian centers have shifted to a damage-control resuscitation approach, focused on providing oxygen-carrying capacity while simultaneously mitigating coagulopathy with a balanced ratio of platelets and plasma to red blood cells. It is unclear to what degree this strategy is used during burn or soft tissue excision. Here, we characterized blood product transfusion during burn and soft tissue surgery and reviewed the published literature regarding intraoperative coagulation changes. We hypothesized that blood product resuscitation during burn and soft tissue excision is not hemostatic and would be insufficient to address hemorrhage-induced coagulopathy. METHODS Consented adult patients were enrolled into an institutional review board–approved prospective observational study. Number, component type, volume, and age of the blood products transfused were recorded during burn excision/grafting or soft tissue debridement. Component bags (packed red blood cells, fresh frozen plasma, platelets, and cryoprecipitate) were collected, and the remaining sample was harvested from the bag and tubing. Aliquots of 1/1,000th the original volume of each blood product were obtained and combined, producing an amalgam sample containing the same ratio of product transfused. Platelet count, rotational thromboelastometry, and impedance aggregometry were measured. Significance was set at p < 0.05. RESULTS Amalgamated transfusate samples produced abnormally weak clots (p ≤ 0.001) particularly if they did not contain platelets. Clot strength (48.8 [2.6] mm; reference range, 49–71 mm) for platelet-containing amalgams was below the lower limit of the reference range despite platelet–red blood cell ratios greater than 1:1. Platelet aggregation was abnormally low; transfused platelets were functionally inferior to native platelets. CONCLUSION Our study and focused review demonstrate that further work is needed to fully understand the needs of patients undergoing tissue excision. The three studies reviewed and the results of our observational work suggest that coagulopathy and thrombocytopenia may contribute to intraoperative hemorrhage. Blood product resuscitation during burn and soft tissue excision is not hemostatic. LEVEL OF EVIDENCE Epidemiologic study, level V.

The risks of severe ionizing radiation exposure are increasing due to the involvement of nuclear powers in combat operations, the increasing use of nuclear power, and the existence of terrorist threats. Exposure to a whole-body radiation dose above about 0.7 Gy results in H-ARS (hematopoietic acute radiation syndrome), which is characterized by damage to the hematopoietic system; higher doses result in further damage to the gastrointestinal and nervous systems. Only a few medical countermeasures for ARS are currently available and approved for use, although others are in development. Cell therapies (cells or products produced by cells) are complex therapeutics that show promise for the treatment of radiation injury and have been shown to reduce mortality and morbidity in animal models. Since clinical trials for ARS cannot be ethically conducted, animal testing is extremely important. Here, we describe cell therapies that have been tested in animal models. Both cells and cell products appear to promote survival and lessen tissue damage after whole-body irradiation, although the mechanisms are not clear. Because radiation exposure often occurs in conjunction with other traumatic injuries, animal models of combined injury involving radiation and future countermeasure testing for these complex medical problems are also discussed.

Introduction: Trauma patients are susceptible to coagulopathy and dysfunctional immune responses. Mesenchymal stromal cells (MSCs) are at the forefront of the cellular therapy revolution with profound immunomodulatory, regenerative, and therapeutic potential. Routine assays to assess immunomodulation activity examine MSC effects on proliferation of peripheral blood mononuclear cells (PBMCs) and take 3–7 days. Assays that could be done in a shorter period of time would be beneficial to allow more rapid comparison of different MSC donors. The studies presented here focused on assays for MSC suppression of mitogen-stimulated PBMC activation in time frames of 24 h or less.Methods: Three potential assays were examined—assays of apoptosis focusing on caspase activation, assays of phosphatidyl serine externalization (PS+) on PBMCs, and measurement of tumor necrosis factor alpha (TNFα) levels using rapid ELISA methods. All assays used the same initial experimental conditions: cryopreserved PBMCs from 8 to 10 pooled donors, co-culture with and without MSCs in 96-well plates, and PBMC stimulation with mitogen for 2–72 h.Results: Suppression of caspase activity in activated PBMCs by incubation with MSCs was not robust and was only significant at times after 24 h. Monitoring PS+ of live CD3+ or live CD4+/CD3+ mitogen-activated PBMCs was dose dependent, reproducible, robust, and evident at the earliest time point taken, 2 h, although no increase in the percentage of PS+ cells was seen with time. The ability of MSC in co-culture to suppress PBMC PS+ externalization compared favorably to two concomitant assays for MSC co-culture suppression of PBMC proliferation, at 72 h by ATP assay, or at 96 h by fluorescently labeled protein signal dilution. TNFα release by mitogen-activated PBMCs was dose dependent, reproducible, robust, and evident at the earliest time point taken, with accumulating signal over time. However, suppression levels with MSC co-culture was reliably seen only after 24 h.Discussion: Takeaways from these studies are as follows: (1) while early measures of PBMC activation is evident at 2–6 h, immunosuppression was only reliably detected at 24 h; (2) PS externalization at 24 h is a surrogate assay for MSC immunomodulation; and (3) rapid ELISA assay detection of TNFα release by PBMCs is a robust and sensitive assay for MSC immunomodulation at 24 h.