Death on the battlefield (2001–2011): Implications for the future of combat casualty care

Massive transfusion on the combat field using autonomous drones: A case report

BACKGROUND

Hemorrhage is a leading cause of preventable deaths in combat settings, requiring rapid blood transfusion to improve survival. While the feasibility of drone-assisted medical logistics has been explored, its practical application in battlefield transfusion remains unreported.

STUDY DESIGN AND METHODS

This case report describes the first documented massive transfusion in a combat environment using an autonomous unmanned aerial vehicle (UAV). A 27-year-old soldier sustained severe lower limb injuries from an improvised explosive device explosion and developed hemorrhagic shock in a remote battlefield location where adverse weather conditions prevented immediate evacuation. In response, 6 units of whole blood and 2 units of fresh frozen plasma were transported via UAV, enabling prehospital transfusion under telemedicine supervision.

RESULTS

The UAV successfully delivered blood products on two consecutive flights, ensuring early resuscitation and stabilization despite delayed evacuation. The casualty's vital signs improved post-transfusion, and surgical interventions were successfully performed following hospital admission. This case demonstrates the feasibility of drone-assisted blood product transport in prolonged field care scenarios.

DISCUSSION

To our knowledge, this is the first reported case of a combat casualty receiving a UAV-facilitated massive transfusion in an operational setting. While UAV-based medical logistics offers a rapid and reliable alternative for remote trauma care, challenges remain in regulatory implementation, blood product stability, and integration into standardized protocols. Further controlled studies are needed to optimize UAV-assisted transfusion strategies and their potential expansion into civilian and disaster response settings.

Effectiveness of prehospital chest decompression in resolving clinical signs of tension pneumothorax

BACKGROUND

Thoracic injuries are a leading cause of morbidity and mortality in military trauma. Tension pneumothorax (TPX) is a critical diagnosis that can lead to rapid hemodynamic and respiratory collapse if untreated. While timely intervention is essential, prehospital TPX diagnosis is challenging and may lead to unnecessary interventions. This study aimed to assess military prehospital chest injury management, including indications for chest decompression and clinical improvement post-intervention.

STUDY DESIGN AND METHODS

Retrospective analysis of the Israel Defense Forces (IDF) Trauma Registry from January 2010 to August 2023 identifying patients who underwent needle or chest tube decompression. Data included demographics, injury mechanisms, vital signs, additional interventions, and prehospital mortality. Chart review evaluated decompression indications and outcomes, with the primary outcome being resolution of decreased oxygen saturation, tachycardia, or hypotension post-decompression.

RESULTS

Overall, 224 patients were included, with a median age of 22 years. The most common injury mechanisms were gunshots (36.6%) and motor vehicle accidents (34.4%). Needle chest decompression was performed in 58.5% of cases, chest tubes in 12.5%, and both in 29.0%. Indications included traumatic cardiac arrest (53.1%), profound shock (17.9%), and SpO2 < 85% (13.8%). In 15.2% of cases, decompression did not meet the IDF guideline criteria. Only three cases (1.3%) showed resolution of tachycardia, hypotension, or low oxygen saturation. In five cases, vital signs briefly returned after traumatic cardiac arrest, but none survived to hospital admission.

DISCUSSION

Chest decompression may be overutilized in prehospital military trauma. Future studies should refine criteria to optimize benefits while minimizing iatrogenic risks.

Assessing direct transfusion feasibility with syringe-based collection of whole blood from universal donors

BACKGROUND

The anticipated multidomain operations of future battlefields necessitates minimalistic medical strategies for treatment of combat wounded. Direct transfusion, involving the administration of blood directly from a donor to a recipient, may be a solution for treating hemorrhagic shock patients in an austere environment where the tools to execute clinical practice guidelines are unavailable.

STUDY DESIGN AND METHODS

Six participants were enrolled in this observational pilot study. Blood was drawn through medical tubing using a 60 mL syringe and pushed through a second medical tubing set with output to a waste container. Three participants were collected with untreated lines, and three collections were performed with heparin flushed lines. Visible clotting was assessed, and blood samples were collected from the output at baseline, after 240 mL of blood collected, and at study endpoint, which was 400 mL collection or termination due excessive clotting or draw difficulties. Coagulation, hematology, and chemistry testing were performed on the samples.

RESULTS

Visible clotting was observed at endpoint in the four procedures with the longest draw times. There were statistically significant differences in platelet count and fibrinogen concentration between baseline and endpoint samples of the non-heparin group. Clot strength decreased over time in the non-heparin group.

DISCUSSION

The association between longer procedure times and visible clotting indicates direct transfusions should be completed based on time constraints rather than target volumes. Maintenance of platelet count, fibrinogen concentration, and clot strength in the heparin group suggest that heparin coated lines may enhance the safety of direct transfusions.

The cost of saving lives: Complications arising from prehospital tourniquet application

BACKGROUND

Uncontrolled hemorrhage is a leading cause of preventable death in trauma. Tourniquets (TQs) are commonly used to control bleeding in the prehospital setting, although their application is associated with risks. Therefore, this study aimed to identify complications arising from TQ use and to examine contributing risk factors.

METHODS

This retrospective observational study reviewed the medical records of adult trauma casualties (>18 years) hospitalized at Chaim Sheba Medical Center (SMC) between 2010 and 2020 who had a TQ applied in the prehospital setting. The primary outcome was the rate and type of complications. Logistic regression analyses identified risk factors using demographic, injury, and clinical data.

RESULTS

From 2010 to 2020, a total of 84 trauma casualties with documented prehospital TQ application were hospitalized at SMC. Of these, 20 (23.81%) experienced TQ-related complications, including local infection, compartment syndrome, and thromboembolism. The average TQ application time was 44.2 min, with no significant difference between those with and without complications. However, significant differences were noted in the mechanism of injury (MOI), wound contamination levels, indications for TQ application, and initial blood test results (p < 0.05). Logistic regression analyses revealed length of stay (LOS) and injuries from falls were significantly associated with the development of complications.

CONCLUSIONS

This study found that a significant trauma in prehospital settings requiring TQ application is associated with a high rate of complications. Early complications, including local infections and compartment syndrome, were more frequent, whereas late complications like thromboembolism and muscle atrophy were less common. The findings suggest that factors such as the MOI and wound contamination may contribute to these complications, yet after applying multivariate regression, LOS and falls were the only variables found to be significantly associated with the development of complications. These findings underscore the need for further research comparing casualties with and without TQ application.

Freeze-dried plasma: Hemostasis and biophysical analyses for damage control resuscitation

BACKGROUND

Effective hemorrhage protocols prioritize immediate hemostatic resuscitation to manage hemorrhagic shock. Prehospital resuscitation using blood products, such as whole blood or alternatively dried plasma in its absence, has the potential to improve outcomes in hemorrhagic shock patients. However, integrating blood products into prehospital care poses substantial logistical challenges due to issues with storage, transport, and administration in field environments.

STUDY DESIGN AND METHODS

We utilized hemostatic assays and advanced biophysical techniques, such as calorimetry, infrared spectoscopy, dynamic light scattering, and biolayer interferometry, to compare the functional and structural properties of freeze-dried plasma (FDP; OctaplasLG Powder, Octapharma AB) with those of fresh plasma controls.

RESULTS

Hemostatic characterization of FDP revealed that clot formation properties and coagulation parameters were largely comparable to fresh plasma controls, with some variations observed in Von Willebrand factor-ADAMTS13 axis and fibrinolysis. No change to moisture content of FDP (~1% water content) was observed after 6-month storage at ambient conditions. Biophysical analyses of FDP during transfusion demonstrated spontaneous exothermic mixing of FDP in plasma, a dilution effect from saline, as well as comparable stability to plasma controls. Quantification of ligand-binding affinities of platelet receptors activated GPIIbIIIa and GPIbα showed comparable binding properties to plasma controls.

CONCLUSION

Our results show that FDP exhibits hemostatic functionality and protein stability on par with fresh plasma, as assessed by novel, highly sensitive techniques. FDP therefore represents a viable alternative to conventional plasma in damage control resuscitation, offering significant logistical and storage advantages for prehospital and remote applications, especially in scenarios where whole blood is unavailable.

An assessment of laboratory changes during autologous whole blood transfusion training: A prospective, observational study

INTRODUCTION

Hemorrhage is the leading cause of death after trauma. Blood transfusions are used to restore physiology but are stored in citrate preservative which can bind electrolytes, particularly calcium, leading to hypocalcemia. Few data exist on the changes that occur in humans because of whole blood donation/transfusion. We sought to determine the electrolyte changes that occur during whole blood donation/reinfusion.

METHODS

We conducted a prospective observational study of military personnel that served as donor/recipient for personnel performing autologous whole blood transfusion training. Trained research staff analyzed whole blood samples collected pre-donation, post-donation, and post-reinfusion of one autologous unit of whole blood. We used the i-STAT laboratory analyzer. Laboratory data are reported using means and standard deviations.

RESULTS

We prospectively enrolled 40 participants. The median age was 22 years (interquartile range [IQR] 20-26), and 95% were male. The median body mass index was 25.3 (IQR 23.0-29.1). There were four participants that reported use of dietary supplements: three reported taking creatine, and the other one reported taking fish oil, magnesium, multivitamin, creatine, caffeine, and beetroot powder. Mean iCa was 1.25 mmol/L (standard deviation [SD] 0.04) pre-donation, 1.26 (SD 0.04) post-donation, and 1.12 (SD 0.14) post-reinfusion. Comparatively, the mean potassium values were 3.90 mEq/L (SD 0.36), 4.10 (SD 0.62), and 4.09 (SD 0.72). Hemoglobin levels decreased by 0.34 g/dL (p < .001) from post-donation to post-reinfusion. Other labs had no significant changes.

CONCLUSIONS

We noted a decrease in ionized calcium measurements post-reinfusion. Future studies should assess changes after larger volume transfusions and assess repletion methods.

Potential military applications for a new freeze-dried plasma

Hemorrhage is a leading cause of potentially preventable death in both military and civilian trauma. Current resuscitation approaches minimize crystalloids and emphasize plasma and other blood components to achieve a balanced transfusion as early as possible after injury. Owing to the nature of military operations, military medical systems must contend with great distances, degraded infrastructure, and harsh environments, as well as combat and humanitarian assistance and disaster relief (HADR) scenarios. These factors limit both patient movement and the ability to deliver blood products to the point of need. Current projections are that future military scenarios will have longer times to reach a medical treatment facility than experienced in recent conflicts, increasing the need for logistically efficient blood products. Freeze-dried plasma (FDP) is rapidly available, easy to use, and shelf-stable at room temperature, making it easier to deliver at the point of need in challenging military environments. For the past 30 years, FDP has been available in only a few countries. Where it has been available, it has become the preferred plasma for austere or military expeditionary settings. Recently, a new FDP, OctaplasLG Powder, was approved in 17 countries worldwide and for emergency use by the Canadian and United States militaries. It is expected that FDP will soon become available to many more militaries. This review discusses the importance of plasma, reassesses the potential military uses of FDP across the range of military operations, and provides a brief discussion of OctaplasLG Powder.

Nationwide estimates of potential lives saved with prehospital blood transfusions

INTRODUCTION

Prehospital blood transfusions result in a significant reduction in mortality risk for injured patients in hemorrhagic shock; however, prehospital blood transfusions have not been widely implemented across the United States. Thus, a paucity of data surrounding the impact of achieving near-complete population-level access to this resource exists. We aimed to determine the number of lives that could potentially have been saved among injured patients in hemorrhagic shock between 2020 and 2023 had prehospital blood products (blood components or whole blood, pBP) been fully implemented.

METHODS

We performed a retrospective review of the National Emergency Medical Services Information System (NEMSIS) from 2020 to 2023 for all trauma patients ≥16 years. Patients with prehospital systolic blood pressure <90 mmHg and heart rate >108 beats per minute, or a systolic blood pressure <70 mmHg, and who did not receive pBP products were included in the analysis. Potential lives saved were calculated using mortality and risk ratio estimates (RR) from previously published studies, assuming 100% nationwide access to pBP. A series of models were developed incorporating varying RR, mortality rate assumptions, and nationwide access to pBP to encompass a wide range of scenarios.

RESULTS

A total of 260,472 patients met our inclusion criteria. Using a 22.1% 24-h mortality rate and an RR of 0.629, 21,356 deaths over the four-year study period could have potentially been saved with the nationwide implementation of pBP.

CONCLUSION

Transfusion of pBP offers the potential to save thousands of injured patients lives. Efforts toward making policy-level interventions aimed at increasing the adoption and availability of pBP should be sought.

Experimental model and simulant for studying blast penetrating injury to the skin

Energised fragments from explosions are the most common wounding mechanism in conflicts and terrorist attacks. Skin covers the vast majority of the human body and is therefore the first anatomical component to be penetrated by fragments, however, its resistance to penetration largely has not been taken into account in models of injury. In this study, an experimental model for ballistic testing of skin is established and a suitable skin simulant for studying resistance to penetration is determined. Fragment-simulating projectiles were fired at human cadaveric skin and skin-simulant candidates. Tissue responses were quantified by evaluating the impact velocity at 50% risk of skin penetration and perforation, and the depth of penetration in cadaveric tissue or skin-simulant candidates. The results identified a 1.5-mm-thick butyl rubber as a suitable skin simulant across the range of threats tested. The findings can help refine assessment of protective systems and predictive models of injury in an effort to improve outcomes of fragment-penetrating injuries.

Finger thoracostomy: Significant risks and unproven benefits in prehospital settings

BACKGROUND

Trauma is a leading cause of preventable death, with a significant portion of trauma deaths occurring in the prehospital setting. Interventions such as chest drainage may play a critical role in managing life-threatening conditions but face challenges due to poorly defined indications and reliance on anecdotal evidence rather than rigorous studies. Among chest drainage techniques, finger thoracostomy (FT) is a well-described, but controversial, method for decompressing the pleural cavity in emergencies like tension pneumothorax or hemothorax. Despite its simplicity and minimal equipment requirements, FT carries risks, including bleeding, infection, organ injury, temporary effects, and procedural failure.

STUDY DESIGN AND METHODS

This study examines eight FT procedures performed by Israel Defense Forces providers during the 2023-2024 "Swords of Iron" War in Gaza.

RESULTS

All patients sustained severe penetrating injuries, with mixed outcomes. One case highlighted severe complications, including infection and empyema weeks later. Additionally, challenges in maintaining up-to-date knowledge and adherence to protocols among reservists led to unauthorized FT procedures, emphasizing the dangers of improvisation without evidence.

DISCUSSION

Our findings, coupled with limited evidence for FT's effectiveness in prehospital settings, raise questions about its appropriateness in trauma care. These concerns highlight the critical importance of adhering to validated and evidence-based protocols in all aspects of medical practice. Deviating from such protocols not only introduces unnecessary risks but also undermines the standardization essential for optimal patient care. Further research is needed to clarify the role, if any, of FT in prehospital trauma management.

Evaluating reimbursement for prehospital blood transfusions: A nationwide survey

BACKGROUND

Prehospital blood transfusion improves survival among patients in hemorrhagic shock but remains underutilized, in part due to financial barriers. However, little is known about how prehospital blood transfusion programs are reimbursed. The objective of this study is to determine the percentage of prehospital blood transfusion programs that receive reimbursement, the percentage of patients receiving blood who were public health insurance-eligible (pediatric and geriatric patients), and the most common reason for blood transfusions in these populations.

STUDY DESIGN AND METHODS

An electronic survey was administered to Emergency Medical Services agencies with an active blood transfusion program in 2024.

RESULTS AND DISCUSSION

Of the 53/150 agencies who responded to the survey, only 6 (11%) agencies reported receiving reimbursement for prehospital blood transfusions. However, 53 (100%) agencies reported transfusing geriatric patients, and 43 (81%) agencies reported transfusing pediatric patients, both groups that are eligible for public health insurance. Medical emergencies were the most common indications for transfusion in geriatric patients, whereas blunt and/or penetrating injuries were the primary indications for transfusion in pediatric patients. For most agencies, geriatric and pediatric patients were frequent recipients of blood transfusions, each comprising up to 50% of the total transfusions administered.

CONCLUSION

Many patients who receive prehospital blood transfusion are public health insurance-eligible. Health policy changes to enable government reimbursement for prehospital blood transfusions would provide critical financial support for this life-saving intervention.

An Observational Study of Combat Medics' Tactical Combat Casualty Care Medication Administration Through a Single-Center Simulated Trauma

INTRODUCTION

Timely battlefield resuscitation improves service member survivability. The Tactical Combat Casualty Care (TCCC) guidelines focus on early interventions to mitigate preventable causes of death. Key to this guideline is the early and correct administration of medications like tranexamic acid (TXA), antibiotics, analgesia, and calcium if indicated. A concerning trend in recent retrospective data reviews has found that combat medics have poor adherence to the TCCC guidelines, specifically inadequate tourniquet placement and underuse of TXA and analgesic medications. It is unknown what role knowledge and training play compared to complex operational factors. This is the first study to assess TCCC medication knowledge and drug administration for commonly used TCCC medications (TXA, calcium, ketamine, and ertapenem) in a simulated trauma training.

MATERIALS AND METHODS

This is a multiple-group cross-sectional observational study of simulated medication administration in accordance with TCCC guidelines. A convenience sample of medics, previously trained in TCCC, completed an individual simulated training that required the administration of 4 commonly used TCCC medications, TXA, calcium, ketamine, and ertapenem. Participant demographic and training data were collected. Trained graders assessed specific skills using a point-based checklist. This study was deemed exempt by the Institutional Review Board.

RESULTS

There were 127 medics who participated, completing 432 unique medication encounters. Individual medications were correctly identified 85% of the time. The appropriate dose was identified 61% of the time. Individual medications were correctly administered 40.7% (95% CI, 34.7-43.1) of the time. Only 7% of participants identified, dosed, and administered all 4 medications correctly. Senior medics had higher rates of drug identification (1.084, 1.006-1.167). There was a trend toward higher rates of dose identification, but it was not significant (1.131, 0.963-1.327). For junior medics, dose identification was positively associated with Table VIII training within 6 months (1.414, 1.119-1.744) and self-perceived TCCC confidence (1.977, 1.271-3.387).

CONCLUSIONS

Significant deficiencies were noted in combat medics' administration of TCCC medications, suggesting that gaps in TCCC knowledge and skills may impact TCCC adherence in the operational environment. Further studies are needed to assess the efficacy of current training, the rate of skills atrophy, and interval training needs.

Association Between Finger Plethysmographic Features and Impedance-Based Thoracic Fluid Content Measurement in a Lower Body Negative Pressure Model of Hemorrhagic Shock

INTRODUCTION

Timely identification of the need for lifesaving intervention in battlefield conditions may be improved through automated monitoring of the injured warfighter. Technologies that combine maximal noninvasive insight with minimal equipment footprint give the greatest opportunity for deployment at scale with inexperienced providers in forward areas. Finger photoplethysmography (PPG) signatures are associated with impending hemorrhagic shock but may be insufficient alone. Transthoracic impedance (TTI) monitoring is a complementary modality to PPG and able to identify volume loss and estimate functional cardiovascular parameters. We sought to understand how PPG features correlate with volume loss estimation from TTI during lower body negative pressure (LBNP) challenge. We hypothesized that features of the PPG waveform would correlate with thoracic fluid content (TFC) as measured by TTI.

MATERIALS AND METHODS

We obtained physiologic monitoring data from healthy adult subjects in LBNP hemorrhagic shock models after local Institutional Review Board and DoD Human Research Protection Office approval. Subjects were excluded for pregnancy, age >45 years, and conditions prohibitive of LBNP exposure. Subjects were instrumented with noninvasive sensors, including a finger PPG sensor and a TTI monitor. Subjects underwent a stepwise LBNP exposure program of -10 mmHg every 10 minutes and notified laboratory staff at first sign of near syncope, terminating the sequential program. TTI data were continuously streamed to a custom program written in MATLAB and time synchronized. To calculate PPG measures, we downsampled data to 250 Hz, screened, and parsed each beat. We featurized each beat to include a systolic, diastolic, and dicrotic notch peak, beat length and area under the curve (AUC), peak-to-peak systolic/diastolic interval, and leading/trailing slopes, all normalized to instantaneous heart rate. Thoracic fluid content was normalized to subjects' pre-LBNP baselines. We summarized all PPG features and the TFC using means (SD) generated as a subject average for each step. We used generalized estimating equation models to examine the relationship between TFC and PPG features while controlling for LBNP stage and subject.

RESULTS

Thirty-two subjects were enrolled; 4 participants were excluded because of sensor malfunction. Twenty-eight subjects had a mean (SD) age of 25.11 (6.66) years. A total of 35.7% of subjects were female. Photoplethysmography analysis demonstrated a decreased systolic-diastolic peak interval, diastolic peak height, and beat AUC with decreased LBNP pressure. End-stage baseline normalized TFC showed an average decrease of 14.68% (±4.98%) (range: 7.54% to 27.69%). The strongest average correlations between stage TFC and PPG occurred in beat length (0.68) and normalized AUC (0.69). In generalized estimating equation models incorporating all stages, beat length, normalized AUC, and the systolic-diastolic interval were all significantly associated with time as a function of LBNP level (P < .001). Thoracic fluid content began decreasing at 12.8 (4.7) minutes, the normalized AUC decreased at 20.7 (7.2) minutes, the beat length decreased at 20.9 (7.0) minutes, and the systolic-diastolic time interval decreased at 30.6 (16.7) minutes.

CONCLUSIONS

While both PPG features and impedance-based TFC trend congruently in the perishock state following LBNP exposure, peripheral pulse wave signals lag redistribution of thoracic fluid volume. Photoplethysmography features of beat length and normalized AUC may serve as a surrogate for TFC when direct thoracic sensing is not available.

Assessing the Trauma System in Ukraine Through the Perspectives of International Healthcare Volunteers and Ukrainian Healthcare Workers: Application of an Observational Tool

INTRODUCTION

Ukraine's health and trauma care system has been devastated by the Russian Federation's invasion in 2022. Previous research shared insight of returned volunteers into changes in the system; however, as the war continues there is the need to understand how the observations of United States (U.S.) volunteers and Ukrainians working in healthcare in Ukraine may differ regarding perceptions of the trauma system's current strengths and challenges.

MATERIALS AND METHODS

We conducted structured interviews with U.S. healthcare or healthcare-adjacent returned volunteers and Ukrainian healthcare workers using the Ukraine Trauma System Assessment Tool Study Region Observation (TSAT SRO) Tool. Mean scores were calculated for each trauma system domain among both Ukrainian and U.S. groups. t-tests were used to determine if there were any statistical differences between these means among the 2 groups.

RESULTS

The overall score for the Ukraine trauma system combining scores from U.S. volunteers and Ukrainians was 1.89 out of a possible 3.00. The domains with the highest combined scores included Prehospital, Chemical, Biological, Radiological, Nuclear, and Explosive (score = 2.33), Prehospital Training (score = 2.25), and Definitive Care Facilities: Blood Product Use (score = 2.38). Domains with the lowest combined scores included Injury Prevention (score = 1.55), Definitive Care Facilities: Disease and Non-Battle Injuries (DNBI) (score = 1.60), and Logistics and Supply (score = 1.55). U.S. volunteers scored every domain lower compared to Ukrainian respondents. All differences between U.S. volunteers and Ukrainian responses were statistically significant except Definitive Care Facilities: Telemedicine, Definitive Care Facilities: Blood Product Use, and Definitive Care Facilities: DNBI.

CONCLUSIONS

TSAT SRO component scoring from observations of U.S. volunteers and Ukrainian healthcare workers suggests the current Ukrainian trauma system is in development. Domain scores differed between U.S. volunteers and Ukrainians; most were statistically significant, demonstrating the importance of including citizens of a nation versus only foreign healthcare workers in assessing a healthcare or trauma system.

Exposure to sub-zero temperatures down to -11 °C does not impact packed red cells storage quality

European guidelines require packed red blood cells (pRBC) to be stored at 2-6 °C. However, negative temperature shifts can occur especially in prehospital transfusion. We investigated the impact of sub-zero temperature exposure on pRBC storage quality. At day 6 post donation (D6), three cohorts (14 pRBC) were put on a supercooled table for 10 h at either - 1 °C, -5 °C, and - 11 °C and compared to a control cohort. Hemolysis, pH and plasma biochemistry were evaluated weekly until D49. Storage-induced micro-erythrocytes (SMEs) were quantified as a surrogate marker for transfusion recovery. The primary endpoint was compliance with European storage standards at D42. The three sub-zero-exposed cohorts met standards at D42. Differences in hemolysis, pH, plasma biochemistry, or SMEs between exposed and control cohorts were non-statistically and/or non-clinically significant. Ten hours exposure to sub-zero temperatures down to -11 °C by conduction maintains storage quality of pRBCs, enabling a wiser risk assessment for potential transfusion use.

Prehospital whole blood use in civilian trauma care: A review of current evidence and practices

ABSTRACT

The use of whole blood (WB) as an adjunct to component therapy has gained popularity for the resuscitation of civilian trauma patients in the last decade. Additionally, it has been shown that earlier transfusion of WB is associated with improved early and late mortality. Despite the proven association of improved outcomes with the emergency transfusion of WB, the role of prehospital whole blood in the resuscitation of hemorrhaging trauma patients remains uncertain because of conflicting results in previous studies. This article will review the existing literature on the use of WB in prehospital settings and the rationale behind its potential advantages among hemorrhaging trauma patients.

LEVEL OF EVIDENCE

Therapeutic/Care Management; Level V.

Treatment of Noncompressible Torso Hemorrhage With Thermoreversible Intra-abdominal Foam: A Dose-response Study in a Porcine Model

INTRODUCTION

Noncompressible torso hemorrhage (NCTH) leads to significant mortality in civilian settings where transport to a trauma center may be delayed and is also the leading cause of exsanguination on the battlefield. Fast Onset Abdominal Management (F.O.A.M.) is a medical device under development that deploys a rapidly expanding thermoreversible foaming agent from a prefilled pressurized canister via an autostopping needle inserted into the peritoneal cavity. Previous pilot and safety studies in porcine models of NCTH have shown that F.O.A.M. increased survival and reached desired intra-abdominal pressure endpoints without significant adverse effects. However, the optimal intra-abdominal deployment pressure for the foaming agent is yet to be determined.

METHODS

In this prospective study, NCTH was modeled using a modified Ross-Burns swine model wherein a grade IV-V liver laceration was made in 40 animals. Each F.O.A.M. device was set to deliver agent to a preset intra-abdominal goal pressure. The pressure for the initial cohort was 60 mmHg and the experimental pressure for each subsequent cohort of animals was selected to be the pressure with the highest posterior probability of being the minimum effective pressure based on an ordinal Bayesian continual reassessment method.

RESULTS

After the allocation of animals to various pressures delivered by the F.O.A.M. device ranging between 50 and 80 mmHg, 33/40 swine had interpretable outcomes (e.g., technically successful device deployments). Based on a priori exclusion criteria, 7 animals were excluded from the analysis, four based on prototype device failure, and three based on off-target needle administration. At the final analysis, two pressures (70 mmHg and 80 mmHg) remained in the 95% credible interval.

CONCLUSIONS

Pressure is the gold standard for effective tamponade of bleeding. In this dose-finding study of the F.O.A.M. device for intra-abdominal tamponade of NCTH in a porcine model, we found a 95% posterior probability that either 70 mmHg or 80 mmHg is the minimum effective pressure as defined in our model. Future studies will be needed to assess long-term survival and adverse events at this pressure.

CounterFlow Hemostatic Gauze Provides Military Medics Confidence and Demonstrates Effective Hemorrhage Control in a Live Tissue Simulation

INTRODUCTION

Trauma-induced hemorrhage is the leading cause of preventable death on the battlefield, with anatomical junctional wounds accounting for ∼19% of deaths. This highlights the need for effective hemorrhage control interventions. Consequently, CounterFlow-Gauze was developed to deliver thrombin, tranexamic acid (TXA), and calcium through a self-propelling acid-base reaction, eliminating the need for manual compression. This study evaluates the usability and efficacy of CounterFlow-Gauze to the Committee on Tactical Combat Casualty Care standard of care, Combat Gauze.

MATERIALS AND METHODS

Ten Canadian Armed Forces medics tested the usability CounterFlow-Gauze and Combat Gauze in a swine junctional hemorrhage model. A 4-mm vascular punch was used to induce femoral injury, followed by a 15-second free bleed. Medics packed the wound and applied 3-minute compression. Medics were blinded to the gauze treatment and completed surveys to evaluate the gauzes. Animals were observed for 3 hours or until death, and blood loss was measured. Blood samples were also collected to measure TXA levels and establish baseline and treated values for blood gas, hematological, and coagulation parameters.

RESULTS

Medics reported enhanced usability and greater efficacy of CounterFlow-Gauze (4.3 ± 0.9/5) compared to Combat Gauze (3.0 ± 1.2 /5; P < .05) in attenuating bleeding. CounterFlow-Gauze achieved high survivability (10/10 animals) and low blood loss (10.21 ± 1.83 g/kg) compared to Combat-Gauze (9/10 animals, 12.72 ± 3.03 g/kg; P > .05), while delivering systemic therapeutic levels of TXA by 30 minutes (10.92 ± 0.17 µg/mL). Changes in mean arterial pressure and heart rate were less pronounced with CounterFlow-Gauze compared to Combat Gauze (P > .05), while no differences were observed between baseline and treated values for any of the other measured parameters.

CONCLUSIONS

The self-propelling hemostatic agents of CounterFlow-Gauze may compensate for suboptimal packing by novice users or in high-stress situations. These findings support the adoption of CounterFlow-Gauze, providing all soldiers access to superior but restricted hemostatic agents in a safe and easy-to-use gauze on the battlefield.

Red cell haemolysis secondary to intraosseous (IO) blood transfusion in adult patients with major trauma: a systematic review

INTRODUCTION

Intraosseous (IO) administration of medications and blood products is accepted practice in major trauma when intravenous access is not immediately available. However, there is a concern that the high infusion pressures required for IO transfusion may increase the risk of red cell haemolysis and its associated complications. The aim of this systematic review is to synthesise the existing evidence describing the risks of red cell haemolysis in IO blood transfusion.

METHODS

We undertook a systematic search of MEDLINE, CINAHL and EMBASE using the search terms: "intraosseous transfusion" and "haemolysis". Two authors independently screened abstracts, and reviewed full-text articles against the inclusion criteria. Reference lists of included studies were reviewed and a grey literature search undertaken. Studies were assessed for risk of bias. Inclusion criteria were: all human and animal study types that reported novel data on IO-associated red cell haemolysis. The Preferred Reporting Items for Systematic Reviews and Meta-Analyses guideline was used.

RESULTS

Twenty-three abstracts were identified; n=9 full papers met the inclusion criteria. No further studies were identified from reference lists or grey literature. These papers included: seven large animal translational studies, a prospective and a retrospective human study. The overall risk of bias was high. One animal study with good translatability to adult patients with trauma demonstrated haemolysis. Other animal studies had methodological constraints that limit their human applicability. No haemolysis was observed in low-density flat bones (sternum), whereas haemolysis was reported in long bones (humerus, tibia). IO infusion using a three-way tap was associated with haemolysis. Conversely, pressure bag transfusion was not associated with haemolysis, but this method may result in insufficient flow rates for effective resuscitation.

CONCLUSIONS

There is a paucity of high-quality evidence surrounding the risks of red cell haemolysis in IO blood transfusion. However, evidence from one study suggests that the likelihood is increased by use of a three-way tap to administer blood transfusion to young adult male patients with trauma. Further research is needed to address this important clinical question.

PROSPERO REGISTRATION NUMBER

CRD42022318902.

The influence of hemorrhagic shock on brain perfusion in a swine model of raised intracranial pressure

PURPOSE

In patients with hemorrhagic shock and an intracranial space occupying lesion (SOL), brain perfusion is severely compromised due to raised intracranial pressure (rICP), significantly worsening outcomes. This study aims to develop a swine model of a SOL with rICP and shock and characterize the effect on brain perfusion.

METHODS

Ten male swine were divided into two groups- normal ICP (nICP) and rICP. rICP animals had an intracranial Fogarty balloon catheter inserted, which was infused with saline to simulate a SOL. Animals underwent hemorrhage to systolic blood pressures (SBP) of 60, 40, and 20mmHg. Cerebral blood flow (CBF) and cerebral blood volume (CBV) were measured using CT perfusion.

RESULTS

The CBF/Mean arterial pressure (MAP) and CBV/MAP curves were modeled using non-linear regression, with both groups demonstrating a sigmoid relation. In both the CBF/MAP and CBV/MAP curves, animals with rICP had loss of autoregulation at a higher MAP compared to nICP. The curves were an excellent fit for CBF (nICP R2 = 0.95; rICP R2 = 0.77) and CBV (nICP R2 = 0.96; rICP R2 = 0.78).

CONCLUSIONS

This study aids in quantifying the compounding insult of raised ICP and hemorrhage with regard to brain perfusion. Raised ICP results in autoregulatory failure at a higher MAP compared to animals with nICP. These results can help inform future studies that should be aimed at evaluating novel interventions for this complex clinical scenario.

Rapid synthesis of degradable ester/thioether monomers and their incorporation into thermoset polyurethane foams for traumatic wound healing

Polyurethane (PUr) foam hemostatic dressings are highly effective at controlling bleeding in traumatic wounds, but their traditionally slow degradation rate requires dressing removal, which could result in wound rebleeding. Incorporating degradable linkages into the PUr network can provide a biodegradable dressing that could be left in place during healing, eliminating rebleeding upon removal and providing scaffolding for new tissue ingrowth with no remains of the applied dressing after healing. In this work, a library of degradable PUr foams was synthesized from degradable monomers based on hydrolytically labile esters and oxidatively labile thioethers using rapid click-chemistry reactions. In a twelve-week in vitro degradation study in 3% hydrogen peroxide and 0.1 M sodium hydroxide, incorporation of degradable monomers resulted in significantly increased PUr foam mass loss, offering biodegradable foam dressings that could better match the rate of traumatic wound healing. Changes to foam chemical, mechanical, thermal, and physical properties throughout degradation were also analyzed. Furthermore, the degradable PUr foams had increased platelet interactions, which could improve foam-induced clotting for a more effective hemostatic dressing. Overall, a biodegradable PUr foam hemostatic dressing could significantly improve healing outcomes in traumatic wounds. STATEMENT OF SIGNIFICANCE: A simple, solvent-free, rapid synthesis technique was developed to provide degradable polythiol monomers for use in polyurethane synthesis. The degradable monomers were incorporated into hemostatic polyurethane foams to provide materials with tunable degradation rates within clinically-relevant time frames. The resulting foams and their degradation byproducts were cytocompatible and hemocompatible, and foams made with the new degradable monomers had enhanced blood clotting, enabling their future use as hemostatic dressings.

Emulsion-Based Encapsulation of Fibrinogen with Calcium Carbonate for Hemorrhage Control

Hemorrhage, particularly non-compressible torso bleeding, remains the leading cause of preventable death in trauma. Self-propelling hemostats composed of thrombin-calcium carbonate (CaCO3) particles and protonated tranexamic acid (TXA+) have been shown to reduce blood loss and mortality in severe bleeding animal models. To further enhance both hemostatic and self-propelling properties, this study was to investigate fibrinogen-CaCO3 particles prepared via a water-oil-water (W/O/W) emulsion method. The particles were characterized using light and fluorescence microscopy, gel electrophoresis, rotational thromboelastometry (ROTEM), and video motion tracking. The method produced spherical micrometer-sized particles with various yields and fibrinogen content, depending on the preparation conditions. The highest yield was achieved with sodium carbonate (SC), followed by ammonium carbonate (AC) and sodium bicarbonate (SBC). AC and paraffin generated smaller particles compared to SC and heptane, which were used as the carbonate source and oil phase, respectively. Fibrinogen incorporation led to an increase in particle size, indicating a correlation between fibrinogen content and particle size. Fluorescence microscopy confirmed successful fibrinogen encapsulation, with various amounts and hemostatic effects as assessed by gel electrophoresis and ROTEM. Combining fibrinogen-CaCO3 particles with TXA+ and thrombin-CaCO3 particles showed synergistic hemostatic effects. All fibrinogen-encapsulated particles exhibited self-propulsion when mixed with TXA+ and exposed to water, regardless of fibrinogen content. This study advances current hemostatic particle technology by demonstrating enhanced self-propulsion and fibrinogen incorporation via the W/O/W emulsion method. Further optimization of the encapsulation method could enhance the effectiveness of fibrinogen-CaCO3 particles for hemorrhage control.

Risk of Severe Sepsis After Blood Product Administration for Traumatic Hemorrhage: A Trauma Quality Improvement Program Study

INTRODUCTION

Transfusion of whole blood (WB) for traumatic hemorrhage has generated renewed interest in civilian trauma based on military experience. The association between blood products and severe sepsis remains unknown. We sought to determine which blood products were associated with the development of severe sepsis.

METHODS

We utilized the TQIP database from 2020 to 2021. We included patients ≥15 ys of age who received at least one blood product and survived at least 24 hs. Severe sepsis is a standardized core quality measure for all reporting centers and defined as sepsis with organ dysfunction. We used descriptive, inferential, and multivariable logistic regression methods to test for associations and adjust for confounders.

RESULTS

There were 83,924 patients included, of whom 1471 met criteria for severe sepsis. Patients with severe sepsis tended to be older (47 versus 42, P < 0.001), male (79% versus 74%, P < 0.001), have a higher injury severity score (29 versus 19, P < 0.001), higher proportion of serious injuries to the thorax (65% versus 47%, P < 0.001), abdomen (54% versus 32%, P < 0.001), and extremities (45% versus 32%, P < 0.001). Severe sepsis patients received more packed red cells, WB, platelets, cryoprecipitate, and plasma. When adjusting for age, sex, mechanism of injury, and injury severity score, WB was positively associated with severe sepsis (unit odds ratio 1.04, 95% confidence interval 1.01-1.07).

CONCLUSIONS

Within this dataset, we found a 4% increased odds of sepsis with each unit of WB received among civilian trauma patients. The effects of blood product administration on immune system function remain unclear. High-quality, prospective explanatory studies are needed to better understand this relationship.

Military-Civilian Partnership to Improve Combat Casualty Care Readiness Among Non-physician Providers

BACKGROUND

Military-civilian partnerships (MCP) provide a bidirectional exchange of information and trauma best practices. In 2021, Penn Presbyterian Medical Center and the U.S. Navy signed a 3-year memorandum of understanding to embed active duty trauma providers into the Trauma Division to facilitate the training and sustainment of combat casualty care (CCC) skills. To date, there is little evidence to demonstrate the efficacy of military-civilian partnerships in maintaining combat casualty readiness in non-physician trauma providers.

METHODS

We evaluated the impact of combat casualty readiness for non-physician providers by mapping clinical experiences in an urban Level I trauma center against the Defense Health Agency's Joint Trauma Systems (JTS) Clinical Practice Guidelines (CPG). The JTS CPGs provide best practices for CCCand highlight the critical skills providers need to know before deploying to an austere environment. Patient acuity data and specific JTS CPG skills performed by a non-physician providers were collected in their respective specialties for each patient seen between January 2023 to January 2024. Analyses were performed using descriptive statistics via Redcap.

RESULTS

A sample of 6 Navy personnel in different specialties: 1 Physician Assistant, 3 Registered Nurses (emergency medicine, perioperative, critical care), and 2 corpsmen (scrub tech and search & rescue/prehospital medic) completed 1299 records on patients treated. In all, 685 (52.7%) were trauma patients and 614 (47.3%) were non-trauma patients. Categories of injuries seen, listed from the most frequent to the least, were as follows: Other (764), Falls (250), Motor Vehicle Crashes (164), Gunshot Wound (126), Stab-related injuries (41). Category 1 skills, defined as "essential to know," were performed in 921 (36.1%) of the patients treated. In Category 2, skills described as "important to know" were performed in 889 (34.8%) of the patients treated. Category 3 skills, identified as "less urgent" as they are rare among trauma patients, were performed in 486 (19.0%) of the patients treated, and 252 (9.8%) required none of the JTS CPG skills. These categories were further broken down based on the frequency of the skills performed. Analysis revealed strengths and identified opportunities to direct clinical experience for underperforming skills.

CONCLUSION

Military-civilian partnerships support CCC readiness. The data presented and the continuation of mapping personnel's clinical experience to military CPGs can gauge readiness in non-physician trauma providers. Notably, several skills in each category were identified as opportunities to modify the clinical exposure of the military provider. These findings indicate that modifications in clinical assignments could enhance active duty combat casualty readiness in these critical skills.

Detection of occult hemorrhage using multivariate non-invasive technologies: a porcine study

Objective.Occult hemorrhage (OH) can emerge subtly post-trauma, especially when internal bleeding is not yet severe enough to result in noticeable hemodynamic changes or shock. Despite normal appearances of traditional vital signs like heart rate (HR) and blood pressure (BP), clinically significant OH may be present, posing a critical diagnostic challenge. Early detection of OH, before vital signs begin to deteriorate, is vital as delays in identifying such conditions are linked to poorer patient outcomes. We analyze the performance of poly-anatomic multivariate technologies-including electrical impedance tomography (EIT), near-infrared spectroscopy (NIRS), electrical impedance spectroscopy (EIS), plethysmography (Pleth), and ECG-in a porcine model of OH. The goal was to detect OH without the need to know the subject's pre-established normal baseline.Approach.Forty female swine were bled at slow rates to create an extended period of subclinical hemorrhage, during which the animals' HR and BP remained stable before hemodynamic deterioration. Continuous vital signs, Pleth, and continuous non-invasive data were recorded and analyzed with the objective of developing an improved means of detecting OH. This detection was set up as a supervised voting classification problem where the measurement of each technology (minimally transformed) was used to train a classifier. A soft majority voting classification technique was then used to detect the existence of OH.Main Results.When comparing the prediction performance of the most significant univariate technology (EIT) to that of a poly-anatomic multivariate approach, the latter achieved higher area-under-the-curve (AUC) values from receiver operating characteristic analyses in almost every observation interval duration. In particular, after 21 min of continuous observation, the best AUC of the multivariate approach was 0.98, while that of the univariate approach was 0.92. The best multivariate technologies, in descending order, appeared to be EIT on the thorax, NIRS on the abdomen, and EIS on the thorax.Significance.In this clinically relevant porcine model of clinically OH, multivariate non-invasive measurements may be superior to univariate ones in detecting OH. Advanced technologies such as EIT, NIRS, and EIS exhibit considerably greater potential to accurately predict OH than standard physiological measurements. From a practical standpoint, our approach would not require the medical device to have prior access to non-hemorrhage baseline data for each patient. Early detection of OH using these technologies could improve patient outcomes by allowing for timely intervention before vital signs begin to deteriorate.

An injectable, expandable polyacrylamide cryogel decreases blood loss and improves survival in a porcine model of junctional hemorrhage

Uncontrolled hemorrhage, including junctional hemorrhage, is a leading cause of preventable death in military trauma. Effective therapies are urgently needed to stabilize patients and prevent further blood loss. We developed an injectable, Expandable Polyacrylamide Cryogel (EPC) that rapidly expands to tamponade bleeding. The hemostatic efficacy of EPC was compared to other hemostatic products in a porcine junctional hemorrhage model. Splenectomized domestic swine (~ 40 kg; N = 37) were randomized to no treatment (N = 8), EPC (N = 7), EPC + thrombin (N = 6), XStat (N = 7), and Combat Gauze (CG, N = 9). They underwent transection of the right femoral artery/vein, followed by 30 s of free bleed, 3 min of manual compression, and observation for up to 3 h. EPC application achieved hemostasis and 100% survival for both formulations, compared to XStat (85%), CG (67%), and no treatment (37%) (p 0.0228, Fisher exact). Mean total blood loss was lowest in EPC groups (~ 590 mL) versus no treatment (1,683 ± 570 mL), XStat (784 ± 407 mL), and CG (1,181 ± 721 mL; p < 0.001 ANOVA). All other endpoints tended to favor the EPC formulations. EPC application for junctional-type injury produced wound tamponade with better survival, reduced blood loss, and better hemodynamic and laboratory parameters compared to no treatment, with trending improvements over XStat and CG.

Coagulation and platelet function in cold-stored whole blood on missions in a helicopter emergency service

BACKGROUND

Haemorrhage is a leading cause of morbidity and mortality in trauma, and prehospital transfusion of blood products is often necessary. Whole blood has been proposed to be the best alternative, but it is unclear whether, and how, storage and transport of the blood in a helicopter affects the blood units. We investigated the coagulation capacity and platelet function in whole blood at different time points during helicopter missions.

METHODS

Twenty units of low-titre group O RhD negative whole blood were collected from healthy volunteers and analysed before, during and after transport in a helicopter. Coagulation and platelet function, as measured by thromboelastography, and blood samples for pH, electrolytes, glucose and lactate were assessed at baseline and 24, 72 and 168 h after storage in the helicopter. Plasma concentrations of coagulation factors and haemoglobin and blood counts were measured at baseline and after 168 h.

RESULTS

Plasma concentrations of coagulation factors and haemoglobin did not change during storage and transport. Platelet counts decreased from a baseline mean of 172 ± 29 × 109/L to a mean of 120 ± 28 × 109/L after 168 h, and platelet function worsened slightly but significantly by 8%-9% during storage and transport. pH and glucose decreased while potassium and lactate levels increased after 168 h compared with baseline.

CONCLUSION

Storage and transport of whole-blood units in a rescue helicopter, for up to 168 h, had a slight impact on the blood quality. Storage of whole blood on board of the helicopter holds up to European standard, measured as temperature and haemolysis.

The impact of spatial structures of collagen on the hemostatic properties of collagen/calcium alginate composite membranes

Biomacromolecule-based hemostatic materials with biocompatibility and biodegradability have become a topic of significant research for the treatment of wound hemorrhage. Among available biomacromolecules, collagen and alginate are particularly promising. Although collagen and alginate composite materials have been developed, the impact of the spatial structures of collagen on the hemostatic properties of these materials remains to be fully understood. Collagen fibers, formed through self-assembly, share the same composition as collagen but exhibit distinct spatial structures. In this study, calcium alginate (CaAlg) membranes containing collagen (Col) or collagen fibers (Col-fiber) were fabricated. By adjusting the ratio of collagen to alginate, Col/CaAlg and Col-fiber/CaAlg composite membranes with favourable tensile strength and water retention ability were selected. The impact of collagen's spatial structures on the structures and properties of composite membranes was investigated, revealing that collagen fibers enhance the cytocompatibility, blood compatibility, and hemostatic performance of alginate membranes more effectively than collagen. Therefore, the Col-fiber/CaAlg membranes could be a promising candidate for hemostatic applications.

A Military-Civilian Training Partnership for Army Nurses

BACKGROUND

In 2018, the U.S. Army Surgeon General created the Army Medical Department Military-Civilian Trauma Team Training (AMCT3) program to enhance the clinical proficiency of medical personnel serving on Army trauma teams called forward resuscitative surgical detachments (FRSDs). FRSDs provide resuscitative and surgical care to wounded patients in the deployed environment until they can be medically evacuated to a higher level of care. Through AMCT3, FRSD personnel work at civilian trauma centers while not deployed in order to maintain their combat casualty care competency.

PURPOSE

This article describes an innovative nursing-specific AMCT3 program model in which Army nurses serving on an FRSD are embedded within a level 1 trauma center for a 3-year assignment. The goal of the program, which was established at Vanderbilt University Medical Center (VUMC) in Nashville, Tennessee, is to improve participants' clinical proficiency and skills in preparation for the next major military conflict, with the aim of reducing preventable battlefield deaths.

METHODS

The VUMC Military Affairs Committee, in consultation with Army medical leaders, developed a unique 3-part model for a nursing partnership program at VUMC. This model includes separate tracks for critical care and emergency nurses. The nurses receive training in their specialty, cross-training in the opposite track, and other professional development opportunities. A critical care nurse and an emergency nurse were assigned to the program in January 2022 and September 2022, respectively.

RESULTS

Between January 2022 and June 2023, the critical care nurse completed all the required individual critical task lists-specialty-specific clinical skills Army medical personnel must be competent in before deployment-except for 1, obtaining intra-abdominal pressure.

CONCLUSION

The VUMC AMCT3 nursing partnership training model ensures that Army nurses are highly prepared to function as part of the FRSD and to provide superior combat casualty care in a resource-limited environment.

Haemostatic resuscitation in practice: a descriptive analysis of blood products administered during Operation HERRICK, Afghanistan

INTRODUCTION

Life-threatening haemorrhage is the leading cause of potentially survivable injury in battlefield casualties. During Operation HERRICK (Afghanistan), mortality rates improved year on year due to a number of advances in trauma care, including haemostatic resuscitation. Blood transfusion practice has not previously been reported in detail during this period.

METHODS

A retrospective analysis of blood transfusion at the UK role 3 medical treatment facility (MTF) at Camp Bastion between March 2006 and September 2014 was performed. Data were extracted from two sources: the UK Joint Theatre Trauma Registry (JTTR) and the newly established Deployed Blood Transfusion Database (DBTD).

RESULTS

3840 casualties were transfused 72 138 units of blood and blood products. 2709 adult casualties (71%) were fully linked with JTTR data and were transfused a total of 59 842 units. Casualties received between 1 unit and 264 units of blood product with a median of 13 units per patient. Casualties wounded by explosion required almost twice the volume of blood product transfusion as those wounded by small arms fire or in a motor vehicle collision (18 units, 9 units, and 10 units, respectively). More than half of blood products were transfused within the first 2 hours following arrival at the MTF. There was a trend towards balanced resuscitation with more equal ratios of blood and blood products being used over time.

CONCLUSION

This study has defined the epidemiology of blood transfusion practice during Operation HERRICK. The DBTD is the largest combined trauma database of its kind. It will ensure that lessons learnt during this period are defined and not forgotten; it should also allow further research questions to be answered in this important area of resuscitation practice.

Tranexamic acid as an adjunct to resuscitative endovascular balloon occlusion of the aorta does not worsen outcomes in a porcine model of hemorrhage

Background

Non-compressible torso hemorrhage (NCTH) represents a leading cause of preventable mortality in trauma. Resuscitative endovascular balloon occlusion of the aorta (REBOA) stabilizes NCTH but may predispose patients to thrombus generation. REBOA must therefore be prospectively evaluated for coagulation risks with concomitant usage of anti-fibrinolytic tranexamic acid (TXA). Using a porcine model of hemorrhage, it was hypothesized that TXA with REBOA would worsen coagulation outcomes and organ damage.

Materials and methods

Thirty-two male Yorkshire swine underwent 30% blood volume hemorrhage with randomization to vehicle control (VC; normal saline), VC+REBOA, TXA, or TXA+REBOA. At T0, animals received 10 mL/minute of group-specific infusion (GSI) followed at T10 by 500 mL of whole blood (WB), second GSI at 13 mL/hour, and Zone 1 REBOA inflation in REBOA groups. At T40, REBOA was deflated, with additional 500 mL WB, and continuation of GSI for 3 hours. Physiological, coagulation, and inflammatory parameters were measured throughout the protocol, with postmortem histopathology.

Results

After REBOA deflation at T40, lactate was significantly higher for the REBOA groups versus the non-REBOA groups, and pH, bicarbonate, and base excess were all significantly lower than the non-REBOA groups. There were no significant differences observed between groups in coagulation, inflammatory, metabolic, or histopathologic parameters.

Conclusions

Administration of TXA with REBOA did not cause more deleterious coagulation outcomes. All significant changes were expected results of REBOA ischemia, and not attributable to TXA treatment. This suggests NCTH can safely be treated with both hemorrhage control methods without exacerbating clotting outcomes.

Level of evidence

Not applicable-basic animal research.

Blood-Based Lateral-Flow Immunoassays Dipstick Test for Damaged Mitochondrial Electron Transport Chain in Pyruvate Treated Rats with Combined Blast Exposure and Hemorrhagic Shock

Blast trauma presents a unique challenge due to its complex mechanism of injury, which impacts the brain and other vital organs through overpressure waves and internal bleeding. Severe blood loss leads to an inadequate oxygen supply and insufficient fuel delivery to cells, impairing ATP production by mitochondria-essential for cell survival. While clinical symptoms of metabolic disruption are evident soon after injury, the molecular, cellular, and systemic damage persists for days to years post-injury. Current challenges in treating traumatic brain injury (TBI) stem from (1) the lack of early blood-based biomarkers for detecting metabolic failure and mitochondrial damage and (2) the limited success of mitochondrial-targeted therapeutic strategies. Objectives: To identify blood-based mitochondrial biomarkers for evaluating the severity of brain injuries and to investigate therapeutic strategies targeting mitochondria. Methods: A preclinical rat model subjected to blast exposure, with or without hemorrhagic shock (HS), followed by resuscitation was utilized. Blood samples were obtained at baseline (T0), post-injury (T60), and at the conclusion of the experiment (T180), and analyzed using a validated dipstick assay to measure mitochondrial enzyme activity. Results: Blast and HS injuries led to a significant decrease in the activity of mitochondrial enzymes, including complex I, complex IV, and the pyruvate dehydrogenase complex (PDH), compared to baseline (p < 0.05). Concurrently, blood lactate concentrations were significantly elevated (p < 0.001). An inverse correlation was observed between mitochondrial enzyme dysfunction and blood lactate levels (p < 0.05). Treatment with sodium pyruvate post-injury restored complex I, complex IV, and PDH activity to near-baseline levels, corrected hyperlactatemia, and reduced reactive oxygen species (ROS) production by mitochondria. Conclusions: Serial monitoring of blood mitochondrial enzyme activity, such as complex I, complex IV, and PDH, may serve as a valuable tool for prognostication and guiding the use of mitochondrial-targeted therapies. Additionally, mitochondrial enzyme assays in blood samples can provide insights into the global redox status, potentially paving the way for novel therapeutic interventions in TBI.

A Joint Trauma System Clinical Practice Guideline: Traumatic Brain Injury Management and Basic Neurosurgery in the Deployed Environment

Management of the patient with moderate to severe brain injury in any environment can be time consuming and resource intensive. These challenges are magnified while forward deployed in austere or hostile environments. This Joint Trauma System Clinical Practice Guideline provides recommendations for the treatment and medical management of casualties with moderate to severe head injuries in an environment where personnel, resources, and follow-on care are limited. These guidelines have been developed by acknowledging commonly recognized recommendations for neurosurgical and neuro-critical care patients and augmenting those evaluations and interventions based on the experience of neurosurgeons, trauma surgeons, and intensivists who have delivered care during recent coalition conflicts.

A Scoping Review of Military Combat Casualty Data on Submassive, Massive, and Supermassive Transfusions

INTRODUCTION

Blood transfusions are common during combat casualty care, aiming to address the loss of blood volume that often accompanies severe battlefield injuries. This scoping review delves into the existing military combat casualty data to analyze the efficacy, challenges, and advances in the use of massive and super-massive transfusions in the management of critically injured warfighters.

MATERIALS AND METHODS

We performed a scoping review of combat-related literature published between 2006 and 2023 pertaining to massive transfusions used during combat deployments. We utilized PubMed to identify relevant studies and utilized the PRISMA-ScR Checklist to conduct the review.

RESULTS

We identified 53 studies that met the inclusion criteria with the majority being retrospective studies from registries used by the United States, British, French, and Dutch Militaries. Most of the studies focused on transfusion ratios, the movement of blood transfusions to more forward locations, implementation of massive transfusions with different fibrinogen-to-red blood cell ratios, the addition of recombinant factor VII, and the use of predictive models for transfusion. Lastly, we identified reports of improved survival for casualties with the rapid implementation of various blood products (warm fresh whole blood, cold-stored low titer group O blood, freeze-dried plasma, and component therapy) and literature relating to pediatric casualties and submassive transfusions. Notable findings include the establishment of hemodynamic and cell blood count parameters as predictors of the requirement for massive transfusions and the association of higher fibrinogen-to-red blood cell ratios with decreased mortality.

CONCLUSIONS

We identified 53 studies focused on blood transfusions from the Global War on Terrorism conflicts. The majority were related to transfusion ratios and the movement of blood transfusions to more forward locations. We highlight key lessons learned on the battlefield that have been translated into scientific developments and changes in civilian trauma methods.

How Much Does Intravenous Fluid Cause Hematocrit to Drop? Improving Interpretation of Hematocrit Toward Better Post-Hemorrhage Care

INTRODUCTION

Hemorrhage is assessed, at least in part, via hematocrit testing. To differentiate unexpected drops in hematocrit because of ongoing hemorrhage versus expected drops as a result of known hemorrhage and intravenous fluid administration, we model expected post-operative hematocrit values accounting for fluid balance and intraoperative estimated blood loss (EBL) among patients without substantial post-operative bleeding.

MATERIALS AND METHODS

We reviewed patient-level data from the electronic health record of an academic medical center for all non-pregnant adults admitted for elective knee or hip arthroplasty from November 2013 to September 2022 who did not require blood products. We used linear regression to evaluate the association between post-operative hematocrit and predictor variables including pre-operative hematocrit, intraoperative net fluid intake, blood volume, time from surgery to lab testing, EBL, patient height, and patient weight.

RESULTS

We included 6,648 cases. Mean (SD) estimated blood volume was 4,804 mL (1023), mean net fluid intake was 1,121 mL (792), and mean EBL was 144 mL (194). Each 100 mL of EBL and 1,000 mL net positive fluid intake was associated with a decrease of 0.52 units (95% CI, 0.51-0.53) and 2.4 units (2.2-2.7) in post-operative hematocrit. Pre-operative hematocrit was the strongest predictor of post-operative hematocrit. Each 1-unit increase in pre-operative hematocrit was associated with a 0.70-unit increase (95% CI, 0.67-0.73) in post-operative hematocrit. Our estimates were robust to sensitivity analyses, and all variables included in the model were statistically significant with P <.005.

CONCLUSION

Patient-specific data, including fluid received since the time of initial hemorrhage, can aid in estimating expected post-hemorrhage hematocrit values, and thus in assessing for the ongoing hemorrhage.

The Efficacy of Whole Blood Resuscitation During Resuscitative Endovascular Balloon Occlusion of the Aorta (REBOA) to Mitigate Post-occlusion Circulatory Collapse: A Translational Model in Large Swine

INTRODUCTION

Uncontrolled torso hemorrhage is the primary cause of potentially survivable deaths on the battlefield. Zone 1 Resuscitative Endovascular Balloon Occlusion of the Aorta (REBOA), in conjunction with damage control resuscitation, may be an effective management strategy for these patients in the prehospital or austere phase of their care. However, the effect of whole blood (WB) transfusion during REBOA on post-occlusion circulatory collapse is not fully understood.

MATERIALS AND METHODS

Yorkshire male swine (n = 6 per group, 70-90 kg) underwent a 40% volume-controlled hemorrhage. After a 10-minute hemorrhagic shock period, a REBOA balloon was inflated in Zone 1. Fifteen minutes after inflation, 0, 1, or 3 units (450 mL/unit) of autologous WB was infused through the left jugular vein. Thirty minutes after initial balloon inflation, the balloon was deflated slowly over 3 minutes. Following deflation, normal saline was administered (up to 3,000 mL) and swine were observed for 2 hours. Survival (primary outcome), hemodynamics, and blood gas values were compared among groups. Statistical significance was determined by log-rank test, one-way ANOVA, and repeated measures ANOVA.

RESULTS

Survival rates were comparable between groups (P = .345) with 66% of control, 33% of the one-unit animals, and 50% of the 3-unit animals survived until the end of the study. Following WB infusion, both the 1-unit and the 3-unit groups had significantly higher blood pressure (P < .01), pulmonary artery pressure (P < .01), and carotid artery flow (P < .01) compared to the control group.

CONCLUSIONS

WB transfusion during Zone 1 REBOA was not associated with increased short-term survival in this large animal model of severe hemorrhage. We observed no signal that WB transfusion may mitigate post-occlusion circulatory collapse. However, there was evidence of supra-normal blood pressures during WB transfusion.

Military influences on the evolution of clinical trials throughout history

Clinical trials of drugs, procedures, and other therapies play a crucial role in advancing medical science by evaluating the safety, efficacy, and optimal use of medical interventions. The design and implementation of these trials have evolved significantly over time, reflecting advancements in medicine, ethics, and methodology. Early historical examples, such as King Nebuchadnezzar II's and his captives' dietary experiment and Ambroise Paré's treatment of gunshot wounds, laid some foundational principles of trial design. The momentum of clinical trial development increased notably with James Lind's 1747 trial for scurvy and continued to progress during World War I with innovations in blood transfusion techniques. World War II (WWII) marked a pivotal moment with breakthroughs in oncology, including the development of the first modern chemotherapeutic agents derived from mustard gas and the introduction of the randomized controlled trial, credited to British epidemiologist Austin Bradford Hill, which revolutionized trial design. More recent conflicts, such as those in Vietnam, Iraq, and Afghanistan, have driven advancements in trauma care, heroin addiction treatment, and hemorrhage management. In response to historical abuses committed by the Nazis during WWII, the evolution of clinical trials has increasingly emphasized ethical standards, particularly informed consent, starting with the Doctors' Trial and the Nuremberg Code. This article discusses how military needs and wartime innovations have shaped modern clinical research, highlighting the interplay between military imperatives and medical progress. Ultimately, clinical trials play an essential role in advancing medical science and improving patient outcomes.

Ionised calcium levels during trauma resuscitation in predicting outcomes-a prospective cohort study

BACKGROUND

Haemorrhage remains the leading cause of preventable mortality following trauma, often aggravated by the acidosis, hypothermia and coagulopathy-the lethal triad of trauma. However, the impact of trauma-induced hypocalcemia on the haemorrhage remains unclear. It is intuitive to consider perturbations of ionised calcium early during trauma resuscitation in acutely injured patients given its pathophysiological significance for an improved outcome. Thus, we conducted a prospective study to analyse the role of ionized calcium ion levels during trauma resuscitation and its association with the need for blood transfusion(s) requirement and mortality.

METHODS

A prospective study was conducted on acutely injured patients with haemorrhage getting admitted to a Level 1 trauma center in India between September 2020 and June 2022. Ionised calcium was measured on arrival, after 6 h, and on day two of the injury to assess the prevalence. The amount of blood transfusion received by the patient was noted along with other demographic and in-hospital details. The association of hypocalcemia with blood transfusion and mortality was also evaluated.

RESULTS

Of the 1961 patients screened for eligibility, 200 patients were recruited and analysed. 72.5% of patients were hypocalcaemic on emergency department (ED) admission. Ionized hypocalcaemia was significantly associated with the need for blood transfusion(s) (p-value < 0.01). A significant association was also noted between ionized hypocalcaemia and mortality (p-value: 0.0085). On the univariate and multivariable analysis, ionized hypocalcaemia was a significant predictor of mortality.

CONCLUSIONS

Ionized hypocalcaemia is widely prevalent among acutely injured. Trauma-induced hypocalcaemia at admission is associated with increased need for blood transfusions and increased mortality.

Protocolized approach saves the limb in peripheral arterial injury: A decade experience

PURPOSE

Outcomes of peripheral arterial injury (PAI) depend on various factors, such as warm ischemia time and concomitant injuries. Suboptimal prehospital care may lead to delayed presentation, and a lack of dedicated trauma system may lead to poorer outcome. Also, there are few reports of these outcomes. The study aims to review our experience of PAI management for more than a decade, and identify the predictors of limb loss in these patients.

METHODS

This is a retrospective analysis of prospectively maintained database of trauma admissions at a level I trauma center from January 2008 to December 2019. Patients with acute upper limb arterial injuries or lower limb arterial injuries at or above the level of popliteal artery were included. Association of limb loss with ischemia time, mechanism of injury, and concomitant injuries was studied using multiple logistic regressions. Statistical analysis was performed using STATA version 15.0 (Stata Corp LLC, Texas).

RESULTS

Out of 716 patients with PAI, the majority (91.9%) were young males. Blunt trauma was the most common mechanism of injury. Median ischemia time was 4 h (interquartile range 2-7 h). Brachial artery (28.5%) was the most common injured vessel followed by popliteal artery (17.5%) and femoral artery (17.3%). Limb salvage rate was 78%. Out of them, 158 (22.1%) patients needed amputation, and 53 (7.4%) had undergone primary amputation. The majority (88.6%) of patients who required primary or secondary amputations had blunt trauma. On multivariate analysis, blunt trauma, ischemia time more than 6 h and concomitant venous, skeletal, and soft tissue injuries were associated with higher odds of amputation.

CONCLUSION

Over all limb salvage rates was 77.9% in our series. Blunt mechanism of injury and associated skeletal and soft tissue injury, ischemia time more than 6 h portend a poor prognosis. Injury prevention, robust prehospital care, and rapid referral to specialized trauma center are few efficient measures, which can decrease the morbidity associated with vascular injury.

Synthesis and evaluation of drug-loaded silver nanoparticles as hemostatic agents to halt uncontrolled bleeding

OBJECTIVE

The aim of this research study was to formulate a cost-effective, stable, less toxic and more efficacious intravenous nanoformulation that could rapidly augment the process of hemostasis.

SIGNIFICANCE

Silver nanoparticles (AgNPs) evoked platelet activation, whereas alum (AM) neutralized the plasma proteins, causing blood coagulation. Tranexamic acid (TA) inhibited fibrinolysis and stabilized the formed blood clot.

METHODS

The nanoformulation (NF) was subjected to characterization techniques such as UV-Vis spectrophotometry, FTIR, XRD, TGA and DSC analysis, which elucidated successful drug conjugation.

RESULTS

Zeta-sizing confirmed the particle size of NF to be 256.6 nm with 0.497 PDI and a zeta potential of + 9.24 mV. In-vitro release profile exhibited first-order kinetics, indicating sustained release, conferring sustained release of NF for 12 h. NF was hemocompatible at the tested doses, as its extent of hemolysis was < 0.8% and < 1%, following EU and FDA guidelines, respectively. Ex-vivo studies revealed that NF recorded the highest viscosity, i.e. 36.5 cP, and maximum mass of clotted blood, i.e. 17.4 mg, in comparison to other combinations. In-vivo studies indicated a 100-fold dose reduction, i.e. 0.1 mg/kg, compared to the marketed formulation, Transamin®, i.e. 10 mg/kg. 10 folds dose reduction, i.e. 1 mg/kg, exhibited more efficacious results than Transamin®, owing to the synergistic effect and nano-sizing of components.

CONCLUSION

A safe, cost-effective, and relatively less toxic hemostatic nanoparticles were formulated, that can be intravenously administered to halt bleeding within seconds.

Platelet to erythrocyte ratio and mortality in massively transfused trauma patients

BACKGROUND

The optimal transfusion ratio of platelets (PLT), plasma and red blood cells (RBC) in trauma patients with massive haemorrhage is still a subject of discussion. The objective of this study is to assess the effect of platelet transfusion on mortality in trauma patients who received massive transfusion.

METHODS

Data were collected from four Dutch level-1 trauma centres. All trauma patients aged ≥ 16 years who received ≥ 6 RBC / 6 h from the time of injury were included. Patients were divided based on PLT:RBC ratio (no platelets, low (<1:5) and high (≥1:5)). Primary outcome measure was 6-hour mortality and secondary outcomes included mortality at other time points and transfusion characteristics.

RESULTS

A total of 292 patients were included. Patients in the high PLT ratio group had lower mortality rates at six and 12 h as compared to the low PLT ratio and no PLT group. In the high PLT group mortality as a result of exsanguination (12 %) was significantly lower as compared to the low PLT group (23 %). High PLT ratio had lower probability for 6-hour mortality multivariable analysis. Higher plasma:RBC ratios were associated with lower mortality at all time points.

CONCLUSIONS

Although the optimal patient specific transfusion strategy in patients with traumatic haemorrhage is still not resolved, these results show that higher PLT to RBC ratios are associated with lower early mortality.

The anatomical distribution of penetrating junctional injuries and their resource implications: A retrospective cohort study

BACKGROUND

There is no standardised definition of what constitutes a junctional injury. Although well described in military literature, this is not the case in the civilian setting. This study aims to characterise the epidemiology of the civilian penetrating junctional injuries in our centre.

METHODS

A retrospective study of all adult and paediatric patients with penetrating injuries to a junctional area presenting to an urban Major Trauma Centre over one year. Data on site of injury, imaging, theatre utilisation, management, and cost was extracted. Differences between patients with injuries to the neck, axillae, diaphragm, groins, buttocks, and multiple injuries, were tested using chi-squared, Kruskal-Wallis and Mann-Whitney-U tests.

RESULTS

Penetrating junctional injuries represented 27 % of all penetrating injuries (132/487). Most patients were young males presenting outside of the hours of 0800-1700. Injuries to the buttocks were most common (n = 50, 38 %) but carried the lowest median ISS of 8. Junctional injuries were very resource intensive utilising 384 images and 183 blood products in just 132 patients. 60 patients required surgical management. In one year, 418 ward-days and 50 ITU-days were required, with an approximated total cost of £914,076. Statistically: significant findings include that the youngest patients presented 1700 - 2000 (p < 0.001). Patients with diaphragm injuries had significantly higher ISS (p < 0.001), received more operations (p < 0.001), stayed on the ward longer (p = 0.002) and were more costly than the other anatomical areas (p < 0.001). Of the areas found adjoining an extremity to the torso, patients with groin injuries had significantly higher ISS (p = 0.025) and were more costly (p = 0.018).

CONCLUSION

Junctional injuries are common and carry a high resource burden. Patients with injuries to the neck, axillae, groin, and buttocks were similar in demographics, resource requirement and cost, although groin injured patients had higher median ISS and cost. Diaphragmatic injuries share some characteristics of junctional injuries, but had significantly higher ISS, blood product use, number of operations, ward length of stay, and cost. The authors support a narrower definition of 'junctional' to exclude diaphragm, such as 'locations adjoining the extremities to the torso'.

Blast injuries: The experience of a level 1 trauma center

BACKGROUND

There is a global surge in blast injuries, which are associated with high morbidity and mortality. To our knowledge, there are no guidelines for the management of blast injuries in the trauma bay.

METHODS

This single-center retrospective cohort study utilized data on all patients admitted to our emergency department (ED) with terror- or combat-related injuries between October 7, 2023 (Gaza Iron Swords War onset) and February 4, 2024. The primary outcome was trauma severity indicated by either an injury severity score (ISS) >15 and/or need for acute care. We also analyzed the mechanisms of injuries, focusing on those resulting from blasts.

RESULTS

Of 208 patients who were admitted following terror-and combat related injuries, 109 patients (101 males [93 %], median age 24.0 years) were admitted following blast injuries. Of them, 88 % were military personnel and 12 % were civilians, with a median ISS of 8 [IQR:4.0-17.0]. The level of trauma was severe in 48 patients (44 %). Tertiary sub-category of blast injuries (P =0.004), chest (P =0.032), abdomen (P =0.018), and lower extremities (P =0.044) injuries were significantly associated with severe trauma. Blast injuries mandated the urgent availability of specialist personnel and appropriate equipment to contend with multiple life-threatening sequelae of exposure to blasts upon the arrival of the victims to emergency services.

CONCLUSION

Blast injuries present unique challenges in management and demand a multidisciplinary approach and specialized resources. We present an algorithm for terror- and combat-related blast injuries treated in our trauma bay. The step-by-step procedures may be applicable to any blast injury sustained under variable conditions.

The modified crABCDE treatment algorithm as recommendation in extreme cold

Trauma care prioritizes life-threatening conditions using the ABCDE algorithm based on the principle "treat first what kills first". As for catastrophic hemorrhage, a leading preventable cause of death in trauma, modifications of this algorithm are necessary in specific cases. In cold climates, life-threatening hypothermia poses additional challenges. Rapid cooling of a patient's core temperature, especially when immobile or poorly insulated, necessitates early prevention. Modified algorithms like the military MhARCH therefore prioritize hypothermia management alongside hemorrhage control in extreme conditions. This article advocates for the crABCDE approach in civilian rescue, emphasizing immediate hypothermia prevention in cold, wet, or high-altitude environments. Tailored protocols that consider environmental risks and patient factors are essential for improving outcomes in both military and civilian trauma care.

Blood far forward: A cross-sectional analysis of prehospital transfusion practices in the Canadian Armed Forces

BACKGROUND

Canadian Armed Forces (CAF) operate in environments that challenge patient care, especially trauma. Military personnel often find themselves in remote settings without conventional healthcare facilities. Treating traumatic injuries, particularly hemorrhagic shock, often necessitates prehospital blood transfusion. This study aims to present an overview of the current CAF prehospital transfusion practices. Furthermore, the study compared current and developing protocols against expert-recommended guidelines.

METHODS

A cross-sectional survey design was employed to describe and compare CAF prehospital blood transfusion practices and protocols against expert recommendations. Topics included protocols, equipment, and procedures. An online survey targeted medical leadership and providers within CAF, with data collected from August 15 to December 15, 2023. Results were summarized descriptively. This study received approval from the Unity Health Toronto Research Ethics Board (REB 23-087).

RESULTS

Units and teams with prehospital blood transfusion capabilities were contacted, achieving a 100 % response rate. Within CAF, Canadian Special Operations Forces Command (CANSOFCOM), Mobile Surgical Resuscitation Team (MSRT), and Canadian Medical Emergency Response Team (CMERT) possess these capabilities, established between 2013 and 2018. These programs are crucial for military operations. CAF has access to standard blood components, cold Leuko-Reduced Whole Blood (LrWB), and factor concentrates from Canadian Blood Services (CBS), available for both domestic and international missions given adequate planning and favorable conditions. Key findings indicate high adherence to recommended practices, some variability in the transfusion process, and potential benefits of standardizing prehospital transfusion practices.

CONCLUSIONS

This study provided insights into CAF's implementation of prehospital transfusion practices, highlighting high adherence to national expert recommendations and the importance of structured protocols in military prehospital trauma management.

IMPLICATIONS OF KEY FINDINGS

CAF's approach and adoption of prehospital transfusion protocols lay a strong foundation for managing trauma patients in remote settings and for expanding prehospital transfusion capabilities across CFHS deployed assets. Further research is needed to advance military trauma care by adapting prehospital blood transfusion to dynamic tactical landscapes and evolving technologies.

Counterfactual reasoning using causal Bayesian networks as a healthcare governance tool

BACKGROUND

Healthcare governance (HG) is a quality assurance processes that aims to maintain and improve clinical practice. Clinical decisions are routinely reviewed after the outcome is known to learn lessons for the future. When the outcome is positive, then practice is praised, but when practice is suboptimal, the area for improvement is highlighted. This process requires counterfactual reasoning, where we predict what would have happened given both what happened and the possible different decisions. Causal models that capture the mechanisms that generate events can support counterfactual reasoning.

OBJECTIVE

This study is an initial attempt to show how counterfactual reasoning with causal Bayesian networks (CBNs) can be used as a HG tool to assess what would have happened if treatments other than those occurred had been selected.

METHODS

Motivated by the Defence Medical Services (DMS) mortality and morbidity (M&M) review meeting, in this paper we (1) extended the use of counterfactual reasoning in CBNs to review decisions, where the alternative treatment strategies and its effect belong to different stages of care, (2) placed counterfactual reasoning in a specific clinical context to examine how it can be used as a HG tool.

RESULTS

Using three realistic examples, we demonstrated how the proposed counterfactual reasoning can be used to assist the DMS M&M review meetings.

CONCLUSIONS

Useful lessons can be learned by assessing decisions after they are made. M&M review meetings are fruitful ground for counterfactual reasoning. The use of a clinical decision support tool that can assist clinicians in assessing counterfactual probabilities will be beneficial.

Detection and Successful Treatment of Gunshot Wound to the Femoral Artery and Vein Four Days Post-incident: A Case Study

This case study presents the successful treatment of a 26-year-old male who experienced profuse bleeding from a gunshot wound to his thigh 4 days after the initial injury. The patient underwent surgery performed by a military vascular surgeon, during which previously undetected injuries to the femoral artery and vein were identified. The surgeon conducted a femoral artery alloprosthesis and sutured the damaged femoral vein. Following the surgery, the patient received post-operative conservative treatment and vacuum-assisted closure therapy, resulting in no complications or development of irreversible ischemic manifestation. The clinical case demonstrates the possible positive effects of placing an endovascular balloon in the main artery (more proximal lesion) for prolonged bleeding control without the use of a tourniquet. In this case, the role of the endovascular balloon was played by a hematoma. As a result, the lower extremity survived 4 days before the arterial blood flow reconstruction was done. Although such a model of bleeding control is absolutely unacceptable for planned specialized surgery or even military surgery at a medical assistance level of II-III, it may be considered as a lifesaving measure when surgical intervention is not immediately available.

In Vivo Evaluation of Two Hemorrhagic Shock Resuscitation Controllers with Non-Invasive, Intermittent Sensors

Hemorrhage is a leading cause of preventable death in military and civilian trauma medicine. Fluid resuscitation is the primary treatment option, which can be difficult to manage when multiple patients are involved. Traditional vital signs needed to drive resuscitation therapy being unavailable without invasive catheter placement is a challenge. To overcome these obstacles, we propose using closed-loop fluid resuscitation controllers managed by non-invasive, intermittent signal sensor inputs to simplify their use in far-forward environments. Using non-invasive, intermittent sensor controllers will allow quicker medical intervention due to negating the need for an arterial catheter to be placed for pressure-guided fluid resuscitation. Two controller designs were evaluated in a swine hemorrhagic shock injury model, with each controller only receiving non-invasive blood pressure (NIBP) measurements simulated from invasive input signals every 60 s. We found that both physiological closed-loop controllers were able to effectively resuscitate subjects out of life-threatening hemorrhagic shock using only intermittent data inputs with a resuscitation effectiveness of at least 95% for each respective controller. We also compared this intermittent signal input to a NIBP cuff and to a deep learning model that predicts blood pressure from a photoplethysmography waveform. Each approach showed evidence of tracking blood pressure, but more effort is needed to refine these non-invasive input approaches. We conclude that resuscitation controllers hold promise to one day be capable of non-invasive sensor input while retaining their effectiveness, expanding their utility for managing patients during mass casualty or battlefield conditions.

The October 7, 2023, Attack on Israel Indicates a Change in Trauma Patterns of Terror Victims, due to the Use of Thermobaric Weapons

INTRODUCTION

The terror attack on October 7, 2023, in southern Israel resulted in approximately 1,200 civilians and security personnel killed. Of the civilians murdered, approximately 200 men, women, and children were murdered inside their homes, while the remaining casualties were murdered in an open field at a music festival, in their cars, or in the streets of local cities.

MATERIALS AND METHODS

Currently, official data have not yet been published regarding the types of injuries suffered by Israeli civilians during the terror attack. However, the massive damage found in buildings infiltrated by the terrorists, weapons found on neutralized terrorists, and the findings of the pathologists tasked with examining and identifying the casualties, as well as preliminary clinical evidence, suggested that many died from hand-held explosive devices or rocket-propelled grenades containing a "thermobaric"-type warhead.

RESULTS

The use of thermobaric weapons has also been reported from the Russia-Ukraine war, suggesting that these weapons are becoming more common in their use. Thermobaric injuries differ from typical battlefield injuries due to their specific blast characteristics. Considering that thermobaric weapons are relatively cheap to manufacture and highly efficient, it can be assumed that their unique injury patterns will become more common in future battlefields.

CONCLUSIONS

This paper reports on a possible change in the nature of terror and battlefield injuries and alerts emergency organizations and military forces worldwide to prepare for the need of treating more blast injuries, burns, smoke inhalation, and asphyxiation.