Causes of death in U.S. Special Operations Forces in the global war on terrorism: 2001-2004

A comprehensive review of massive transfusion and major hemorrhage protocols: origins, core principles and practical implementation

Until the beginning of the century, bleeding management was similar in elective surgeries or exsanguination scenarios: clotting tests were used to guide blood product orders and, while awaiting these results, an aggressive resuscitation with crystalloids was recommended. The high mortality rate in severe hemorrhages managed with this strategy endorsed the need for a special resuscitation plan. As a result, modifications were recommended to develop a new clinical approach to these patients, called "Damage Control Resuscitation". This strategy includes four principles: damage control surgery, minimization of crystalloids, permissive hypotension and hemostatic resuscitation. The latter involves the use of antifibrinolytics, correction of preconditions of hemostasis (calcium, pH and temperature) and the early and rapid restoration of intravascular volume with blood products. To enable timely availability and transfusion of blood products, specific actions in different hospital areas need to be synchronized, which are usually organized through Massive Transfusion Protocols or, as they have recently been rebranded, Major Hemorrhage Protocols (MHPs). Although these bundles of actions represent a paradigm change, essential aspects such as their historical evolution, theoretical foundations, terminology and operational elements have yet to be well explored. Considering the wide application range of these tools (emergency departments, interventional radiology, operating rooms and military fields), it is essential to integrate all professionals involved with severe hemorrhage scenarios in the implementation of the aforementioned protocols, from conception to execution and management. This review paper addresses MHP aspects relevant to anesthesiologists, transfusion services and other areas involved with the care of patients with severe bleeding.

Aintree Catheter Versus Gum Elastic Bougie for Airway Exchange Using the i-Gel Supraglottic Device: A Cadaver Study

INTRODUCTION

Airway compromise is the third leading cause of preventable death on the battlefield. Most combat medics carry supraglottic airway (SGA) devices for airway management. However, exchanging an SGA device for a definitive airway can be challenging, especially in austere environments. This study aims to compare the Aintree intubation catheter (AIC) to the gum elastic bougie (GEB) as adjuncts for performing airway device exchange with the i-gel SGA device in place.

MATERIALS AND METHODS

This randomized crossover cadaver study of 48 participants examined the success rate of two endotracheal introducers (AIC and GEB) when performing a blind airway exchange with an i-gel in place. Study participants were combat medics (MOS 68W), physician assistant students, physician assistant staff, emergency medicine (EM) physician residents, and emergency medicine attending physicians attending classes at the installation Medical Simulations Training Center. Each participant performed up to three attempts using both endotracheal tube introducers on the same cadaver. The primary outcome was successful airway exchange rate with each device, and the secondary outcome was time to successful airway exchange.

RESULTS

Although the AIC had a slightly higher success rate of 33% compared to the GEB success rate of 30%, this result was not statistically significant, P = .56. Similarly, participants completed successful airway exchanges with the AIC faster, with a mean time of 86.5 seconds (95% CI: 71.2 to 101.9) versus 101.2 seconds (95% CI: 85.5 to 116.9) with the GEB. However, this result was also not statistically significant, P = 0.18.

CONCLUSIONS

This study demonstrates no significant difference in success rate and time to completion of successful iterations of airway exchanges between the two devices. Although the AIC performed slightly better overall, these results are not statistically significant. Additionally, blind exchange intubations appear to be of high risk with minimal success, so we recommend against this technique in routine practice.

Prognostic Value of ISS and TRISS Scores in Tunisian Terrorism Victims

INTRODUCTION

Injuries caused by terrorism attacks are one of the urgent problems of the society and the health system. In this work, we aimed to assess the injury severity score (ISS) and trauma injury severity score (TRISS) in Tunisian military combatants injured during terrorism attacks.

MATERIALS AND METHODS

A total of 153 victims of terrorism admitted to the Military Hospital of Tunis between January 2012 and January 2017 were included. Among them, 107 survived and 46 died (43 victims died at the terrorist attack scene and 3 died in the hospital). All dead patients were autopsied. Injury severity scores and TRISSs were then calculated by 2 professors in the anesthesia-resuscitation department, and the agreement level was assessed using the Bland and Altman curve.

RESULTS

We obtained a strong agreement between the 2 experts when assessing the TRISS and ISS. Using the Bland and Altman curve, an agreement between the 2 experts was obtained between 0 to 40 and 60 to 75 for the ISS and between 0 to 25 and 75 to 100 for the TRISS. Moreover, we detected a high level of ISS and TRISS, especially in deceased victims compared to survivors (P <.001). To predict mortality, we revealed by the receiver operating characteristic curve high sensitivity and specificity (more than 90%) before day 28 of hospital stay as well as for ISS and TRISS. Regarding the mechanism of injury, patients injured by gunshot have higher ISSs and TRISSs than those injured by explosion (P < .001).

CONCLUSIONS

Injury severity scores and TRISSs showed a high reliability to predict the mortality rate in Tunisian victims of terrorism.

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.

[Surgical management of severe noncompressible torso and organ hemorrhages]

BACKGROUND

Noncompressible torso hemorrhages (NCTH) are now recognized as the leading cause of preventable death in the context of severe military and civilian injuries. Approximately 20% of all trauma patients still die from uncontrolled bleeding associated with rapidly evolving disorders of blood coagulation function.

OBJECTIVE

Summary of recent advances in the field of nonsurgical and surgical management, presentation of current treatment concepts and future research directions.

MATERIAL AND METHODS

Selective literature review and analysis.

RESULTS

The concepts for the early treatment of NCTH have considerably evolved over the last decade. The updated definition of NCTH includes a combination of high-grade anatomic body trunk injury, hemodynamic instability, urgent need for hemorrhage control, and aggressive hemostatic treatment. The treatment concepts consider the following 3 aspects: controlling the source of bleeding (close the tap), maintaining organ perfusion and restoring hemostasis (fill the tank) and increasing the body's resistance to ischemia (upgrade the armor). New tools, well-established damage control concepts and early and aggressive therapeutic intervention for hemostatic failure have significantly improved the outcomes.

CONCLUSION

Future research needs to refine and validate the current concepts for further clinical application.

'Golden day' is a myth: rethinking medical timelines and risk in large scale combat operations

The evolving landscape of battlefield medicine forces medical planners to prepare for large-scale combat operations (LSCO) against peer adversaries, requiring reassessment of recent medical strategies. Despite lacking medical backing, the term 'golden day' has been used by senior military leaders to link the resuscitative benefits of the 'golden hour' to prolonged medical care through similar nomenclature. Pseudomedical terminology can easily enter the lexicon of commanders as attractive soundbites. However, articulating the evidence-based factors influencing mortality on the battlefield is critical to effectively articulate risk to commanders. The challenges of LSCO will be significant with increased casualty numbers and treatment constraints. Realistic medical and operational planning is critical to maximising survival, with a clear understanding of what can and cannot be achieved. Recent improvements in trauma care, such as early haemorrhage control, advanced prehospital care and rapid evacuation to surgical care, have significantly reduced mortality rates. Given the predictability of when casualties die from significant injuries, the absence of timely clinical interventions will increase avoidable battlefield deaths. If evacuation to surgical care is extended to 24 hours, many more casualties will die from potentially survivable injuries. Medical planners must recognise the potential challenges associated with LSCO including contested, delayed evacuation which predicts a tripling of mortality rates from 10% to 30%. Leaders must appreciate the unchanging human physiologic response to injury and historical combat casualty statistics when preparing commanders and politicians for the excess in mortality during LSCO. Without candour, plans will be unrealistic, causing non-medical leaders and the public to be unprepared.

Management of Acute Wounds-Expert Panel Consensus Statement

Significance: The Wound Healing Foundation recognized the need for consensus-based unbiased recommendations for the treatment of wounds. As a first step, a consensus on the treatment of chronic wounds was developed and published in 2022. The current publication on acute wounds represents the second step in this process. Acute wounds may result from any number of conditions, including burns, military and combat operations, and trauma to specific areas of the body. The management of acute wounds requires timely and evidence-driven intervention to achieve optimal clinical outcomes. This consensus statement provides the clinician with the necessary foundational approaches to the causes, diagnosis, and therapeutic management of acute wounds. Presented in a structured format, this is a useful guide for clinicians and learners in all patient care settings. Recent Advances: Recent advances in the management of acute wounds have centered on stabilization and treatment in the military and combat environment. Specifically, advancements in hemostasis, resuscitation, and the mitigation of infection risk through timely initiation of antibiotics and avoidance of high-pressure irrigation in contaminated soft tissue injury. Critical Issues: Critical issues include infection control, pain management, and the unique considerations for the management of acute wounds in pediatric patients. Future Directions: Future directions include new approaches to preventing the progression and conversion of burns through the use of specific gel formulations. Additionally, the use of three-dimensional bioprinting and photo-modulation for reconstruction is a promising area for continued discovery.

Artificial blood for therapeutic and laboratory usage: Where do we stand?

The scarcity of blood for transfusion purposes has been widely acknowledged. Surgical therapeutic processes, war zones, and post-disaster treatments demand a huge amount of blood. Modern-day laboratories also require blood for bioengineering experimentation. Therefore, an artificially devised solution capable of mimicking the blood functions from biological and engineering relevance would be a noteworthy discovery of contemporary science. The experience drawn from discarded century-old blood substitutes has led us to technologically more advanced present-day solutions, which are better at carrying out the physiological functions of blood. Aiming at safety, stability, non-toxicity, and compatibility in terms of immuno-response, a remarkable number of substitutes are being tried to mimic the physiological properties and functions of red blood cells, platelets, plasma, and white blood cells. Despite significant efforts and time devoted, for transfusion, no product so far has been able to replace natural blood. This article puts together the important developments in blood substitutes that have evolved over the years, including substitutes for clinical as well as engineering requirements. It also points out the recent endeavors of synthesizing blood cells through modern synthetic routes. It has been highlighted that none of the blood substitutes have achieved the required efficacy so that they can be used in vivo. Finally, the emerging trends and future research needs have been stressed upon.

A PROMPT Update on Partial REBOA: Initial Clinical Data and Overview of the DoD-Funded Partial REBOA Outcomes Multicenter ProspecTive (PROMPT) Study

INTRODUCTION

Retrograde Endovascular Balloon Occlusion of the Aorta (REBOA) is an effective management for the transient responder, but the ischemic consequences of complete aortic occlusion currently limit its use. Multiple DoD-funded preclinical studies have clearly demonstrated that partial REBOA reduces distal ischemia to potentially extend safe occlusion times, while still providing effective temporization of noncompressible torso hemorrhage. Early versions of REBOA devices were designed to completely occlude the aorta and had little ability to provide partial occlusion. Recently, a new REBOA device (pREBOA-PRO) was designed specifically to allow for partial occlusion, with the hypothesis that this may reduce the complications of aortic occlusion and extend safe occlusion times while maintaining the benefits on cardiac and cerebrovascular circulation as well as reductions in resuscitation requirements.

MATERIALS AND METHODS

To ascertain the impact of a new purpose-built partial REBOA device on the extension of safe occlusion time, the Partial REBOA Outcomes Multicenter ProspecTive (PROMPT) trial compared available data from the pREBOA-PRO with existing data from 200 clinical uses of pREBOA-PRO and available data in the AAST AORTA Registry were reviewed to design primary endpoints and clinical evidence for a prospective multi-center trial, the PROMPT Study. Together with the endpoints identified in preclinical studies of partial REBOA, primary endpoints for the PROMPT study were identified and power analyses were conducted to determine the target patient enrollment goals.

RESULTS

Results from the clinical implementation of partial REBOA at a single trauma center were used to conduct the initial power analysis for the primary endpoint of Acute Kidney Injury (AKI) after prolonged occlusion. The rate of AKI after complete REBOA was 55% (12/20) compared to 33% (4/12) after partial REBOA (Madurska et al., 2021). With an alpha of 0.05 and power (β) of 0.8, the projected sample size for comparison on a dichotomous outcome is 85 patients for the assessment of AKI. Initial power and endpoint analyses have been confirmed and extended with the ongoing analysis of partial and complete REBOA reported in the AORTA database. These analyses confirm preclinical findings which show that compared to complete REBOA, partial REBOA is associated with extended occlusion time in zone 1 (complete: 31 min vs. partial: 45 min, P = 0.003), lower rates of AKI after zone 1 occlusion (complete: 33% vs. partial: 19%, P = 0.05) and reduced resuscitation requirements (e.g., 25% reduction in pRBC administration: complete: 18 units vs. partial: 13 units, P = 0.02).

CONCLUSIONS

The DoD-funded PROMPT study of partial REBOA will provide prospective observational clinical data on patients being treated with pREBOA-PRO. Outcomes will be stratified based on partial or complete occlusion to address whether partial REBOA has additional clinical benefits over complete REBOA, such as decreased distal ischemia, extension of safe occlusion time, improved hemodynamics during transition to and from occlusion, and reduced interoperative bleeding and blood product use. The results from this study are expected to confirm previous data demonstrating reduction of ischemic sequalae, improved transition to reperfusion, and reduced resuscitative requirements compared to complete REBOA.

A trauma expert consensus: Capabilities are required early to improve survivability from traumatic injury

BACKGROUND

Mortality reviews examine US military fatalities resulting from traumatic injuries during combat operations. These reviews are essential to the evolution of the military trauma system to improve individual, unit, and system-level trauma care delivery and inform trauma system protocols and guidelines. This study identifies specific prehospital and hospital interventions with the potential to provide survival benefits.

METHODS

US Special Operations Command fatalities with battle injuries deemed potentially survivable (2001-2021) were extracted from previous mortality reviews. A military trauma review panel consisting of trauma surgeons, forensic pathologists, and prehospital and emergency medicine specialists conducted a methodical review to identify prehospital, hospital, and resuscitation interventions (e.g., laparotomy, blood transfusion) with the potential to have provided a survival benefit.

RESULTS

Of 388 US Special Operations Command battle-injured fatalities, 100 were deemed potentially survivable. Of these (median age, 29 years; all male), 76.0% were injured in Afghanistan, and 75% died prehospital. Gunshot wounds were in 62.0%, followed by blast injury (37%), and blunt force injury (1.0%). Most had a Maximum Abbreviated Injury Scale severity classified as 4 (severe) (55.0%) and 5 (critical) (41.0%). The panel recommended 433 interventions (prehospital, 188; hospital, 315). The most recommended prehospital intervention was blood transfusion (95%), followed by finger/tube thoracostomy (47%). The most common hospital recommendations were thoracotomy and definitive vascular repair. Whole blood transfusion was assessed for each fatality: 74% would have required ≥10 U of blood, 20% would have required 5 to 10 U, 1% would have required 1 to 4 U, and 5% would not have required blood products to impact survival. Five may have benefited from a prehospital laparotomy.

CONCLUSION

This study systematically identified capabilities needed to provide a survival benefit and examined interventions needed to inform trauma system efforts along the continuum of care. The determination was that blood transfusion and massive transfusion shortly after traumatic injury would impact survival the most.

LEVEL OF EVIDENCE

Prognostic and Epidemiological; Level V.

Who needs a tourniquet? And who does not? Lessons learned from a review of tourniquet use in the Russo-Ukrainian war

BACKGROUND

Extremity tourniquets have proven to be lifesaving in both civilian and military settings and should continue to be used by first responders for trauma patients with life-threatening extremity bleeding. This is especially true in combat scenarios in which both the casualty and the first responder may be confronted by the imminent threat of death from hostile fire as the extremity hemorrhage is being treated. Not every extremity wound, however, needs a tourniquet. One of the most important aspects of controlling life-threatening extremity bleeding with tourniquets is to recognize what magnitude of bleeding requires this intervention and what magnitude of bleeding does not. Multiple studies, both military and civilian, have shown that tourniquets are often applied when they are not medically indicated. Overuse of extremity tourniquets has not caused excess morbidity in either the recent conflicts in Iraq and Afghanistan or in the US urban civilian setting. In the presence of prolonged evacuation, however, applying a tourniquet when it is not medically indicated changes tourniquet application from being a lifesaving intervention to one that may cause an avoidable amputation and the development of an array of metabolic derangements and acute kidney injury collectively called prolonged tourniquet application syndrome.

METHODS

The recent literature was reviewed for papers that documented the complications of tourniquet use resulting from the prolonged casualty evacuation times being seen in the current Russo-Ukrainian war. The literature was also reviewed for the incidence of tourniquet application that was found to not be medically indicated, in both the US civilian setting and from Ukraine. Finally, an in-person meeting of the US/Ukraine Tourniquet Working Group was held in Warsaw, Poland, in December of 2023.

RESULTS

Unnecessary loss of extremities and life-threatening episodes of prolonged tourniquet application syndrome are currently occurring in Ukrainian combat forces because of nonindicated tourniquet use combined with the prolonged evacuation time seen in the Russo-Ukrainian war. Specific numbers of the complications experienced as a result of tourniquet use by Ukrainian forces in the current conflict are treated as classified information and are not available, but multiple sources from the Ukrainian military medical personnel and from the US advisors providing medical assistance to Ukraine have all agreed that the problem is substantial.

CONCLUSION

Unnecessary tourniquet morbidity might also occur in US forces in a variety of potential future combat scenarios in which evacuation to surgical care is delayed. Prehospital trauma training programs, including but not limited to tactical combat casualty care, place insufficient emphasis on the need to avoid leaving tourniquets in place when they are not medically indicated. This aspect of training should receive emphasis in future Tactical Combat Casualty Care (TCCC) and civilian first responder curriculum development. An interim ad hoc training solution on this topic is available at the websites noted in this articles. Additional training modalities may follow in the near future.

LEVEL OF EVIDENCE

Therapeutic/Care Management; Level V.

Causes of mortality in military working dog from traumatic injuries

Introduction

This study aimed to identify the pathophysiologic causes of death following traumatic injuries in military working dogs (MWDs) and determine the risk factors associated with mortality in MWD following traumatic injuries. The results of this study will allow for better targeting of interventions to ameliorate these pathophysiologic causes of death and inform research priorities directed at the pathophysiology that leads to the death of MWDs.

Methods

The final dataset for this study was compiled by using two previously established datasets. Based on review of available data and supplemental records (when available), MWDs in which a definitive cause of death could be determined were included in the study population. These MWDs were assigned a cause of death based on categories previously identified in studies evaluating service member casualties. A group of MWDs who survived their traumatic injury and had similar mechanisms of injury and types of injury to the deceased MWDs were included to allow for comparison and establishment of risk factors associated with MWD death. Variables collected included breed, age, sex, mechanism of injury, survival/non-survival, type of trauma, mechanism of injury, pathophysiology that led to death and pre-hospital care provided. Statistical analysis included Fishers exact test for categorical variables and univariable and multivariable logistic regression to identify factors associated with the MWD death.

Results

A total of 84 MWDs (33 non-survivors and 51 survivors) were included in this study. Of the 33 MWDs that died, 27 (81.8%) were noted to be dead on arrival. The pathophysiologic causes of death were found to be hemorrhage (45.5% [n = 15]), head trauma (21.2% [n = 7]), catastrophic tissue destruction (15.2% [n = 5]), pneumothorax (9.1% [n = 3]) and one (3% [n = 1]) of each of the following: septic shock, asphyxiation and burns. Military working dogs that did not receive non-DVM care were 3.55 times more likely to die than those that did receive non-DVM care (95% CI 1.03-12.27). The majority of MWDs died of their injuries before reaching veterinary care.

Discussion

To increase the survival of MWDs on the battlefield, further research should focus on developing new interventions and techniques to mitigate the effects of the pathophysiology noted to cause MWD death. Furthermore, given that care by a non-DVM was found to be associated with survival, the implementation of pre-hospital care and early resuscitation techniques should be a continued priority for those treating MWDs at both the point of injury and in the prehospital setting.

A Review of 75th Ranger Regiment Battle-Injured Fatalities Incurred During Combat Operations From 2001 to 2021

INTRODUCTION

The 75th Ranger Regiment is an elite U.S. military special operations unit that conducted over 20 years of sustained combat operations. The Regiment has a history of providing novel and cutting-edge prehospital trauma care, advancing and translating medical initiatives, and documenting and reporting casualty care performance improvement efforts.

MATERIALS AND METHODS

A retrospective case fatality rate (CFR) review, mortality review, and descriptive analysis of fatalities were conducted for battle-injured personnel assigned or attached to the 75th Ranger Regiment from 2001 to 2021 during combat operations primarily in Afghanistan and Iraq. Fatalities were evaluated for population characteristics, cause of death, mechanism of death, injury severity, injury survivability, and death preventability.

RESULTS

A total of 813 battle injury casualties, including 62 fatalities, were incurred over 20 years and 1 month of continuous combat operations. The Regiment maintained a zero rate of prehospital preventable combat death. Additionally, no fatalities had a mechanism of death because of isolated extremity hemorrhage, tension pneumothorax, or airway obstruction. When comparing the CFR of the Regiment to the U.S. military population as a whole, the Regiment had a significantly greater reduction in the cumulative CFR as measured by the difference in average annual percentage change.

CONCLUSIONS

Documentation and analysis of casualties and care, mortality and casualty reviews, and other performance improvement efforts can guide combatant commanders, medical directors, and fighting forces to reduce preventable combat deaths and the CFR. Early hemorrhage control, blood product resuscitation, and other lifesaving interventions should be established and maintained as a standard prehospital practice to mitigate fatalities with potentially survivable injuries.

Effective approaches to address noncompressible torso hemorrhage

PURPOSE OF REVIEW

Noncompressible torso hemorrhage (NCTH) is now considered as the major cause of preventable death after both severe military and civilian trauma. Around 20% of all trauma patients still die from uncontrolled exsanguination along with rapidly evolving hemostatic failure. This review highlights the most recent advances in the field and provides an outline for future research directions.

RECENT FINDINGS

The updated definition of NCTH includes a combination of high-grade anatomical torso injury, hemodynamic instability, urgent need for hemorrhage control and aggressive hemostatic resuscitation. Therapeutic concepts consider the following three aspects: control the bleeding source (close the tap), resuscitate to maintain organ perfusion and restore hemostasis (fill the tank), and increase the body's resistance against ischemia (upgrade the armor).

SUMMARY

The concepts for the early management of NCTH have substantially evolved over the last decade. The development of new devices and techniques combined with early intervention of hemostatic failure have contributed to more successful resuscitations. Future research needs to refine and validate their potential clinical application.

The employment of resuscitative endovascular balloon occlusion of the aorta in deployed settings

BACKGROUND

Resuscitative endovascular balloon occlusion of the aorta (REBOA) has been often used in place of open aortic occlusion for management of hemorrhagic shock in trauma. There is a paucity of data evaluating REBOA usage in military settings.

STUDY DESIGN AND METHODS

We queried the Department of Defense Trauma Registry (DODTR) for all cases with at least one intervention or assessment available within the first 72 h after injury between 2007 and 2023. We used relevant procedural codes to identify the use of REBOA within the DODTR, and we used descriptive statistics to characterize its use.

RESULTS

We identified 17 cases of REBOA placed in combat settings from 2017 to 2019. The majority of these were placed in the operating room (76%) and in civilian patients (70%). A penetrating mechanism caused the injury in 94% of cases with predominantly the abdomen and extremities having serious injuries. All patients subsequently underwent an exploratory laparotomy after REBOA placement, with moderate numbers of patients having spleen, liver, and small bowel injuries. The majority (82%) of included patients survived to hospital discharge.

DISCUSSION

We describe 17 cases of REBOA within the DODTR from 2007 to 2023, adding to the limited documentation of patients undergoing REBOA in military settings. We identified patterns of injury in line with previous studies of patients undergoing REBOA in military settings. In this small sample of military casualties, we observed a high survival rate.

Evaluating time until ligation in a novel tourniquet - A crossover randomized-controlled trial

INTRODUCTION AND AIM

Severe external hemorrhage is a significant reason for morbidity and mortality in adults; thus, the swift and correct application of a tourniquet by laypersons can be lifesaving. We conducted this randomized-controlled cross-over study to investigate the use of a novel tourniquet.

METHODS

Participants were recruited at the Heidelberg University Hospital. Eligible participants were ≥ 18 years old with a medical background but without prior experience in applying a tourniquet. Participants were 1:1 randomized to the intervention group (PAX tourniquet) or the control group (SAM or CAT tourniquet). In the control group, participants underwent another randomization to either the SAM or CAT tourniquet without a predefined allocation ratio. Hyperspectral measurements were undertaken (i) before ligation, (ii) 30 s after ligation, and (iii) 30 s after the reopening of the tourniquet. The primary outcome was time until ligation before crossover between the respective groups. The analysis of secondary endpoints included all attempts to assess a possible learning effect, intraoperator variability, and hyperspectral measurements. Participants were crossed to the other study group after a brief wash-out phase.

RESULTS

In total, 50 participants were recruited, resulting in 100 attempts. A success rate of 98% was observed across the study population. Time until ligation was 49 s and 56 s (p = 0.572) in the intervention and control group, respectively. However, there was a significant difference between the PAX and SAM (54 vs 75 s; p = 0.037) and the SAM and CAT tourniquet (75 vs. 47 s; p = 0.015). Further, we observed a significant learning effect in participants allocated to the control group first, with a median reduction of 9 s in the time until ligation. Hyperspectral measurements showed a significant decrease in perfusion and tissue oxygenation after ligation. Further, a significant increase in perfusion and tissue oxygenation was found after reopening the tourniquet compared to the baseline measurement.

CONCLUSION

The novel PAX tourniquet can be applied quickly and effectively by medical personnel without prior experience in applying a tourniquet.

Safety of the injectable expanding biopolymer foam for non-compressible truncal bleeding in swine

BACKGROUND

A novel hydrophobically modified chitosan (hm-chitosan) polymer has been previously shown to improve survival in a non-compressible intra-abdominal bleeding model in swine. We performed a 28-day survival study to evaluate the safety of the hm-chitosan polymer in swine.

METHODS

Female Yorkshire swine (40-50 kg) were used. A mild, non-compressible, closed-cavity bleeding model was created with splenic transection. The hm-chitosan polymer was applied intra-abdominally through an umbilical nozzle in the same composition and dose previously shown to improve survival. Animals were monitored intraoperatively and followed 28 days postoperatively for survival, signs of pain, and end-organ function. Gross pathological and microscopic evaluations were performed at the conclusion of the experiment.

RESULTS

A total of 10 animals were included (hm-chitosan = 8; control = 2). The 2 control animals survived through 28 days, and 7 of the 8 animals from the hm-chitosan group survived without any adverse events. One animal from the hm-chitosan group required early termination of the study for signs of pain, and superficial colonic ulcers were found on autopsy. Laboratory tests showed no signs of end-organ dysfunction after exposure to hm-chitosan after 28 days. On gross pathological examination, small (<0.5 cm) peritoneal nodules were noticed in the hm-chitosan group, which were consistent with giant-cell foreign body reaction in microscopy, presumably related to polymer remnants. Microscopically, no signs of systemic polymer embolization or thrombosis were noticed.

CONCLUSION

Prolonged intraperitoneal exposure to the hm-chitosan polymer was tolerated without any adverse event in the majority of animals. In the single animal that required early termination, the material did not appear to be associated with end-organ dysfunction in swine. Superficial colonic ulcers that would require surgical repair were identified in 1 out of 8 animals exposed to hm-chitosan.

Torso hemorrhage: noncompressible? never say never

Since limb bleeding has been well managed by extremity tourniquets, the management of exsanguinating torso hemorrhage (TH) has become a hot issue both in military and civilian medicine. Conventional hemostatic techniques are ineffective for managing traumatic bleeding of organs and vessels within the torso due to the anatomical features. The designation of noncompressible torso hemorrhage (NCTH) marks a significant step in investigating the injury mechanisms and developing effective methods for bleeding control. Special tourniquets such as abdominal aortic and junctional tourniquet and SAM junctional tourniquet designed for NCTH have been approved by FDA for clinical use. Combat ready clamp and junctional emergency treatment tool also exhibit potential for external NCTH control. In addition, resuscitative endovascular balloon occlusion of the aorta (REBOA) further provides an endovascular solution to alleviate the challenges of NCTH treatment. Notably, NCTH cognitive surveys have revealed that medical staff have deficiencies in understanding relevant concepts and treatment abilities. The stereotypical interpretation of NCTH naming, particularly the term noncompressible, is the root cause of this issue. This review discusses the dynamic relationship between TH and NCTH by tracing the development of external NCTH control techniques. The authors propose to further subdivide the existing NCTH into compressible torso hemorrhage and NCTH' (noncompressible but REBOA controllable) based on whether hemostasis is available via external compression. Finally, due to the irreplaceability of special tourniquets during the prehospital stage, the authors emphasize the importance of a package program to improve the efficacy and safety of external NCTH control. This program includes the promotion of tourniquet redesign and hemostatic strategies, personnel reeducation, and complications prevention.

Advanced Non-compressible Torso Hemorrhage Management is Combat Casualty Care's Moon Shot

Non-compressible torso hemorrhage continues to cause considerable preventable mortality on the battlefield. In this editorial, we highlight the burden of deaths, the most at-risk torso structures, current interventions, and their limitations and recommendations for future research and device development.

Impact of Immunopathy and Coagulopathy on Multi-Organ Failure and Mortality in a Lethal Porcine Model of Controlled and Uncontrolled Hemorrhage

Uncontrolled hemorrhage is a major preventable cause of death in patients with trauma. However, the majority of large animal models of hemorrhage have utilized controlled hemorrhage rather than uncontrolled hemorrhage to investigate the impact of immunopathy and coagulopathy on multi-organ failure (MOF) and mortality. This study evaluates these alterations in a severe porcine controlled and uncontrolled hemorrhagic shock (HS) model. Anesthetized female swine underwent controlled hemorrhage and uncontrolled hemorrhage by partial splenic resection followed with or without lactated Ringer solution (LR) or Voluven® resuscitation. Swine were surveyed 6 h after completion of splenic hemorrhage or until death. Blood chemistry, physiologic variables, systemic and tissue levels of complement proteins and cytokines, coagulation parameters, organ function, and damage were recorded and assessed. HS resulted in systemic and local complement activation, cytokine release, hypocoagulopathy, metabolic acidosis, MOF, and no animal survival. Resuscitation with LR and Voluven® after HS improved hemodynamic parameters (MAP and SI), metabolic acidosis, hyperkalemia, and survival but resulted in increased complement activation and worse coagulopathy. Compared with the LR group, the animals with hemorrhagic shock treated with Voluven® had worse dilutional anemia, coagulopathy, renal and hepatic dysfunction, increased myocardial complement activation and renal damage, and decreased survival rate. Hemorrhagic shock triggers early immunopathy and coagulopathy and appears associated with MOF and death. This study indicates that immunopathy and coagulopathy are therapeutic targets that may be addressed with a high-impact adjunctive treatment to conventional resuscitation.

Nalbuphine: an underrecognized battlefield analgesic and its utilization in combat care and peripheral areas

Battlefield injuries result in acute and severe uncontrolled pain, which can be reduced with the early use of analgesia. Apart from pain, battlefield injuries may also cause significant morbidity and a prolonged period of absence from active duty. Traditionally available opioids are known to cause various undesirable side effects such as respiratory depression that may worsen the condition of an already injured combatant. Nalbuphine is an opioid agonist-antagonist and has been increasingly used for postoperative analgesia over the last decade. In India, it is the only opioid analgesic that does not come under the Controlled Substances Act at the time of this publication. In today's world, where nalbuphine is being recommended for acute pain worldwide, its use in the Indian combat scenario needs to be conceptualized at the medical officer level (primary caregiver). This conceptualization will be discussed in detail in this review article.

Prehospital tourniquet placement in extremity trauma

BACKGROUND

Extremity tourniquets (ET) use has increased in trauma systems to manage traumatic hemorrhage. This study aims to evaluate prehospital ET placement.

METHODS

This is a retrospective review of a prospectively collected cohort of 211 adult patients who underwent prehospital ET placement over 3 ½ years. Data regarding ET placement was analyzed regarding ET applier, reported indications, extremity appearance at arrival and outcomes.

RESULTS

A total of 211 patients had completed data sheets. Of these patients, 63.2% had no other intervention prior to ET placement. On arrival, nearly 1/3 of the patients had palpable pulses with ET in place and less than ½ had arterial bleeding upon ET release.

DISCUSSION/CONCLUSIONS

This study shows that ET are frequently used as the initial intervention in the field. It is of paramount importance that we adapt our first responders training to teach wound assessment and appropriate steps in management of extremity hemorrhagic trauma.

Low-titer group O whole blood in military ground ambulances: Lessons from the Israel Defense Forces initial experience

BACKGROUND

Cold-stored low-titer group O whole blood (LTOWB) has become increasingly utilised in both prehospital and in-hospital settings for resuscitation of traumatic haemorrhage. However, implementing the use of LTOWB to ground medical teams has been limited due to logistic challenges.

METHODS

In 2022, the Israel Defense Forces (IDF) started using LTOWB in ambulances for the first time in Israel. This report details the initial experience of this rollout and presents a case-series of the first patients treated with LTOWB.

RESULTS

Between January-December 2022, seven trauma patients received LTOWB administered by ground IDF intensive care ambulances after presenting with profound shock. Median time from injury to administration of LTOWB was 35 min. All patients had evidence of severe bleeding upon hospital arrival with six undergoing damage control laparotomy and all but one surviving to discharge.

CONCLUSIONS

The implementation of LTOWB in ground medical units is in its early stages, but continued experience may demonstrate its feasibility, safety, and effectiveness in the prehospital setting. Further research is necessary to fully understand the indications, methodology, and benefits of LTOWB in resuscitating severely injured trauma patients in this setting.

Preparation and exchange transfusion effect of a double polymerization human umbilical cord haemoglobin of red blood cell substitute

The development of haemoglobin-based oxygen carrier (HBOC) is an excellent supplement to pre-hospital emergency blood transfusions. In this study, a new type of HBOC was prepared by using human cord haemoglobin (HCHb) and glutaraldehyde (GDA) and Bis(3,5-dibromosalicyl) fumarate (DBBF) to modify (DBBF-GDA-HCHb), the changes of physicochemical indexes during its preparation were evaluated, while a traditional type of GDA-HCHb was prepared, and the oxygen-carrying capacity of two type of HBOC was evaluated by a rat model of 135.0% exchange transfusion (ET). Eighteen SD male rats were selected, and were randomly divided into control group (5.0% albumin), DBBF-GDA-HCHb group and GDA-HCHb group. The 12 h survival rate of the C group was 16.67%, and the two HBOC groups were both 83.33%. Compared with GDA-HCHb, DBBF-GDA-HCHb can reduce lactic acid content by supplying oxygen to hypoxic tissues in a more timely manner, and can also can improve the reduction of MAP due to ischaemia.

Rethinking limb tourniquet conversion in the prehospital environment

We have highlighted the issue of overuse of tourniquets and described why tourniquet conversion and replacement should be taught and done in the prehospital setting.

Continued Development and Testing of a Novel Steerable Chest Tube, Extendable Infusion Cannula, and Portable Suction-Infusion Pump for Use in Austere and Transport Environments to Prevent Retained Hemothorax

With blunt and penetrating trauma to the chest, warfighters frequently suffer from hemothorax. Optimal management requires the placement of a chest tube to evacuate the blood. Malposition of the tube may be a causative factor of inadequate drainage (retained hemothorax). As a potential solution, we developed a previously reported steerable chest tube allowing accurate placement into a desired location to enhance effectiveness. To provide assisted aspiration, we developed a portable, battery-operated suction device capable of simultaneous or sequential infusion. This report details the ongoing progress of this project. Updated steerable tube and pump prototypes were designed and produced. The tubes were tested for feasibility in two pigs and one cadaver by fluoroscopically comparing tip positions after insertion by a number of providers. Measured drainage volumes comparing standard vs. steerable tubes after pleural infusion of 1,000 mL of saline in two pigs were compared. Testing of the pump focused on the accuracy of suction and volume functions. The steerable tube prototype consists of sequentially bonded segments of differing flexibility and an ergonomic tensioning handle. The portable suction pump accurately provides up to 80 cmH2O of suction, an infusion capability of up to 10 mL/min, and a 950 mL removable reservoir canister. After minimal training, providers easily and repeatedly placed the tip of the steerable tube in the lateral diaphragmatic sulcus in animals and cadavers. Arc was limited to the distal segment. Compared to a standard tube, the steerable tube placed along the diaphragm improved pleural fluid drainage volumes by 17%, although this did not reach statistical significance in six trials. These new prototypes represent substantial improvements and were performed according to expectations. We believe that this steerable chest tube and portable suction-infusion pump can be effectively used for warfighters with chest injuries in austere environments.

The prognostic value of an age-adjusted BIG score in adult patients with traumatic brain injury

Background

The base deficit, international normalized ratio, and Glasgow Coma Scale (BIG) score was previously developed to predict the outcomes of pediatric trauma patients. We designed this study to explore and improve the prognostic value of the BIG score in adult patients with traumatic brain injury (TBI).

Methods

Adult patients diagnosed with TBI in a public critical care database were included in this observational study. The BIG score was calculated based on the Glasgow Coma Scale (GCS), the international normalized ratio (INR), and the base deficit. Logistic regression analysis was performed to confirm the association between the BIG score and the outcome of included patients. Receiver operating characteristic (ROC) curves were drawn to evaluate the prognostic value of the BIG score and novel constructed models.

Results

In total, 1,034 TBI patients were included in this study with a mortality of 22.8%. Non-survivors had higher BIG scores than survivors (p < 0.001). The results of multivariable logistic regression analysis showed that age (p < 0.001), pulse oxygen saturation (SpO2) (p = 0.032), glucose (p = 0.015), hemoglobin (p = 0.047), BIG score (p < 0.001), subarachnoid hemorrhage (p = 0.013), and intracerebral hematoma (p = 0.001) were associated with in-hospital mortality of included patients. The AUC (area under the ROC curves) of the BIG score was 0.669, which was not as high as in previous pediatric trauma cohorts. However, combining the BIG score with age increased the AUC to 0.764. The prognostic model composed of significant factors including BIG had the highest AUC of 0.786.

Conclusion

The age-adjusted BIG score is superior to the original BIG score in predicting mortality of adult TBI patients. The prognostic model incorporating the BIG score is beneficial for clinicians, aiding them in making early triage and treatment decisions in adult TBI patients.

Military Medicine's Value to US Health Care and Public Health: Bringing Battlefield Lessons Home

Importance

Military medicine in the US was established to treat wounded and ill service members and to protect the health and well-being of our military forces at home and abroad. To accomplish these tasks, it has developed the capacity to rapidly adapt to the changing nature of war and emerging health threats; throughout our nation's history, innovations developed by military health professionals have been quickly adopted by civilian medicine and public health for the benefit of patients in the US and around the world.

Observations

From the historical record and published studies, we cite notable examples of how military medicine has advanced civilian health care and public health. We also describe how military medicine research and development differs from that done in the civilian world. During the conflicts in Afghanistan and Iraq, military medicine's focused approach to performance improvement and requirements-driven research cut the case fatality rate from severe battlefield wounds in half, to the lowest level in the history of warfare.

Conclusions and Relevance

Although innovations developed by military medicine regularly inform and improve civilian health care and public health, the architects of these advances and the methods they use are often overlooked. Enhanced communication and cooperation between our nation's military and civilian health systems would promote reciprocal learning, accelerate collaborative research, and strengthen our nation's capacity to meet a growing array of health and geopolitical threats.

United States Military Fatalities During Operation Inherent Resolve and Operation Freedom's Sentinel

BACKGROUND

Military operations provide a unified action and strategic approach to achieve national goals and objectives. Mortality reviews from military operations can guide injury prevention and casualty care efforts.

METHODS

A retrospective study was conducted on all U.S. military fatalities from Operation Inherent Resolve (OIR) in Iraq (2014-2021) and Operation Freedom's Sentinel (OFS) in Afghanistan (2015-2021). Data were obtained from autopsy reports and other existing records. Fatalities were evaluated for population characteristics; manner, cause, and location of death; and underlying atherosclerosis. Non-suicide trauma fatalities were also evaluated for injury severity, mechanism of death, injury survivability, death preventability, and opportunities for improvement.

RESULTS

Of 213 U.S. military fatalities (median age, 29 years; male, 93.0%; prehospital, 89.2%), 49.8% were from OIR, and 50.2% were from OFS. More OIR fatalities were Reserve and National Guard forces (OIR 22.6%; OFS 5.6%), conventional forces (OIR 82.1%; OFS 65.4%), and support personnel (OIR 61.3%; OFS 33.6%). More OIR fatalities also resulted from disease and non-battle injury (OIR 83.0%; OFS 28.0%). The leading cause of death was injury (OIR 81.1%; OFS 98.1%). Manner of death differed as more homicides (OIR 18.9%; OFS 72.9%) were seen in OFS, and more deaths from natural causes (OIR 18.9%; OFS 1.9%) and suicides (OIR 29.2%; OFS 6.5%) were seen in OIR. The prevalence of underlying atherosclerosis was 14.2% in OIR and 18.7% in OFS. Of 146 non-suicide trauma fatalities, most multiple/blunt force injury deaths (62.2%) occurred in OIR, and most blast injury deaths (77.8%) and gunshot wound deaths (76.6%) occurred in OFS. The leading mechanism of death was catastrophic tissue destruction (80.8%). Most fatalities had non-survivable injuries (80.8%) and non-preventable deaths (97.3%).

CONCLUSIONS

Comprehensive mortality reviews should routinely be conducted for all military operation deaths. Understanding death from both injury and disease can guide preemptive and responsive efforts to reduce death among military forces.

The forgotten cohort-lessons learned from prehospital trauma death: a retrospective cohort study

BACKGROUND

Trauma related deaths remain a relevant public health problem, in particular in the younger male population. A significant number of these deaths occur prehospitally without transfer to a hospital. These patients, sometimes termed "the forgotten cohort", are usually not included in clinical registries, resulting in a lack of information about prehospitally trauma deaths. The aim of the present study was to compare patients who died prehospital with those who sustained life-threatening injuries in order to analyze and potentially improve prehospital strategies.

METHODS

This cohort study included all primary operations carried out by Switzerland's largest helicopter emergency medical service (HEMS) between January 1, 2011, and December 31, 2021. We included all adult trauma patients with life-threatening or fatal conditions. The outcome of this study is the vital status of the patient at the end of mission, i.e. fatal or life-threatening. Injury, rescue characteristics, and interventions of the forgotten trauma cohort, defined as patients with a fatal injury (NACA score of VII), were compared with life-threatening injuries (NACA score V and VI).

RESULTS

Of 110,331 HEMS missions, 5534 primary operations were finally analyzed, including 5191 (93.8%) life-threatening and 343 (6.2%) fatal injuries. More than two-thirds of patients (n = 3772, 68.2%) had a traumatic brain injury without a significant difference between the two groups (p > 0.05). Thoracic trauma (44.6% vs. 28.7%, p < 0.001) and abdominal trauma (22.2% vs. 16.1%, p = 0.004) were more frequent in fatal missions whereas pelvic trauma was similar between the two groups (13.4% vs. 12.9%, p = 0.788). Pneumothorax decompression rate (17.2% vs. 3.7%, p < 0.001) was higher in the forgotten cohort group and measures for bleeding control (15.2% vs. 42.7%, p < 0.001) and pelvic belt application (2.9% vs. 13.1% p < 0.001) were more common in the life-threating injury group.

CONCLUSION

Chest decompression rates and measures for early hemorrhage control are areas for potential improvement in prehospital care.

Hydrophobic aerogel-modified hemostatic gauze with thermal management performance

Current hemostatic agents or dressings are not efficient under extremely hot and cold environments due to deterioration of active ingredients, water evaporation and ice crystal growth. To address these challenges, we engineered a biocompatible hemostatic system with thermoregulatory properties for harsh conditions by combining the asymmetric wetting nano-silica aerogel coated-gauze (AWNSA@G) with a layer-by-layer (LBL) structure. Our AWNSA@G was a dressing with a tunable wettability prepared by spraying the hydrophobic nano-silica aerogel onto the gauze from different distances. The hemostatic time and blood loss of the AWNSA@G were 5.1 and 6.9 times lower than normal gauze in rat's injured femoral artery model. Moreover, the modified gauze was torn off after hemostasis without rebleeding, approximately 23.8 times of peak peeling force lower than normal gauze. For the LBL structure, consisting of the nano-silica aerogel layer and a n-octadecane phase change material layer, in both hot (70 °C) and cold (-27 °C) environments, exhibited dual-functional thermal management and maintained a stable internal temperature. We further verified our composite presented superior blood coagulation effect in extreme environments due to the LBL structure, the pro-coagulant properties of nano-silica aerogel and unidirectional fluid pumping of AWNSA@G. Our work, therefore, shows great hemostasis potential under normal and extreme temperature environments.

Comparison of hydroxocobalamin with other resuscitative fluids in volume-controlled and uncontrolled hemorrhage models in swine ( Sus-scrofa )

BACKGROUND

Traumatic hemorrhage is the leading cause of preventable death in military environments. Treatment with resuscitative fluids and blood components is based on availability, thus, frequently unavailable in the prehospital setting, due to lack of resources and costs. Hydroxocobalamin (HOC), increases blood pressure via nitric oxide scavenging. We evaluated HOC as a resuscitation fluid, in two swine hemorrhage models. Our objectives were to (1) evaluate whether HOC treatment following hemorrhagic shock improves hemodynamic parameters and (2) determine whether those effects are comparable to whole blood (WB) and lactated ringers (LR).

METHODS

Yorkshire swine (S us scrofa ) (n = 72) were used in models of controlled hemorrhage (CH) (n = 36) and uncontrolled hemorrhage (UH) (n = 36). Randomized animals received treatment with 500 mL of either WB, LR, HOC (150 mg/kg), followed by a six-hour observation (n = 6 each group). Survival, hemodynamics, blood gases (ABGs) and chemistries were collected. Data reported as mean ± standard error of the mean and statistical analysis by ANOVA ( p < 0.05).

RESULTS

Blood loss for CH was 41% ± 0.02 versus 33% ± 0.07 for UH. For CH, HOC treatment maintained higher systolic blood pressure (sBP, mm Hg) compared with WB and LR (72 ± 1.1; 60 ± 0.8; 58 ± 1.6; respectively). Heart rate (HR), cardiac output (CO), Sp o2 and vascular resistance were comparable with WB and LR. The ABG values were comparable between HOC and WB. For UH, HOC treatment maintained sBP levels comparable to WB and higher than LR (70 ± 0.9; 73 ± 0.5; 56 ± 1.2). HR, CO, Sp o2 , and systemic vascular resistance were comparable between HOC and WB. Survival, hemodynamics, blood gases were comparable between HOC and WB. No survival differences were found between cohorts.

CONCLUSION

Hydroxocobalamin treatment improved hemodynamic parameters and Ca 2+ levels compared with LR and equivalent to WB, in both models. Hydroxocobalamin may be a viable alternative when WB is not available.

Nonfatal Injuries From Falls Among U.S. Military Personnel Deployed for Combat Operations, 2001-2018

INTRODUCTION

Falls are a leading mechanism of injury. Hospitalization and outpatient clinic visits due to fall injury are frequently reported among both deployed and non-deployed U.S. Military personnel. Falls have been previously identified as a leading injury second only to sports and exercise as a cause for non-battle air evacuations.

MATERIALS AND METHODS

This retrospective study analyzed the Department of Defense Trauma Registry fall injury data from September 11, 2001 to December 31, 2018. Deployed U.S. Military personnel with fall listed as one of their mechanisms of injury were included for analysis.

RESULTS

Of 31,791 injured U.S. Military personnel captured by the Department of Defense Trauma Registry within the study time frame, a total of 3,101 (9.8%) incurred injuries from falls. Those who had fall injuries were primarily 21 to 30 years old (55.4%), male (93.1%), Army (75.6%), and enlisted personnel (56.9%). The proportion of casualties sustaining injuries from falls generally increased through the years of the study. Most fall injuries were classified as non-battle injury (91.9%). Falls accounted for 24.2% of non-battle injury hospital admissions with a median hospital stay of 2 days. More non-battle-related falls were reported in Iraq-centric military operations (62.7%); whereas more battle-related falls were reported in Afghanistan-centric military operations (58.3%).

CONCLUSIONS

This study is the largest analysis of deployed U.S. Military personnel injured by falls to date. Highlighted are preventive strategies to mitigate fall injury, reduce workforce attrition, and preserve combat mission capability.

LEVEL OF EVIDENCE

Level III Epidemiologic.

Decreasing lower extremity junctional and perineal injury from explosive blast with a pelvic protection system

OBJECTIVE

Lower extremity junctional injuries due to explosive blasts are among the most lethal sustained on the battlefield. To help reduce the effects of junctional and perineal trauma from this injury mechanism, a tiered Pelvic Protection System (PPS) was fielded during the war in Afghanistan.

METHODS

Thirty-six patients with known PPS status who sustained traumatic above knee amputations, with and without perineal injuries, were identified from an operative amputation registry in Helmand Province, Afghanistan, spanning a 12-month period.

RESULTS

In Group 1 patients with above knee amputations who wore some tier of the PPS system, 47% (8 of 17) sustained junctional/perineal injuries. Of the patients in Group 2 who wore no PPS, 68% (13 of 19) sustained perineal injuries associated with proximal amputations. Overall, these differences were statistically significant (p = 0.0115).

CONCLUSION

Use of a PPS may reduce the risk of having severe perineal and lower extremity junctional injury in service members sustaining traumatic above knee amputations from an explosive blast.

[Cricothyrotomy : Data situation, guidelines and techniques for the definitive surgical airway]

Cricothyrotomy represents the final approach to secure the airway, in the course of which less invasive measures have failed. It can also primarily be carried out to establish a secure airway. This is essential to protect the patient from a significant hypoxia. This is a cannot ventilate-cannot oxygenate (CVCO) situation, which presumably all colleagues in emergency intensive care medicine and anesthesia have already been confronted with. Evidence-based algorithms for the management of a difficult airway and CVCO have been established. If oxygenation using an endotracheal tube, an extraglottic airway device or bag-valve mask ventilation all fail, the airway must be surgically secured, i.e. using cricothyrotomy. The prevalence of the CVCO situation in a prehospital setting is ca. 1%. No valid prospective randomized in vivo studies have been carried with respect to the question of the best method.

Initial Serum Levels of Magnesium and Calcium as Predictors of Mortality in Traumatic Brain Injury Patients: A Retrospective Study

Background: We sought to evaluate the predictor role of the initial serum level of calcium and magnesium in hospitalized traumatic brain injury (TBI) patients. Materials and methods: A retrospective analysis of all TBI patients admitted to the Hamad Trauma Center (HTC), between June 2016 and May 2021 was conducted. Initial serum electrolyte levels of TBI patients were obtained. A comparative analysis of clinical variables between patients with abnormal and normal serum electrolyte level was performed. Logistic regression analysis with the variables that showed a significant difference (p < 0.05) in the bivariate analysis was performed to calculate the odds ratios (OR) for mortality. Results: There was a total of 922 patients with clinical records of serum electrolyte levels at admission. Of these, 757 (82.1%) had hypocalcemia, 158 (17.1%) had normal calcium level, and 7 (0.8%) had hypercalcemia. On the other hand, 616 (66.8%) patients had normal magnesium level, 285 (30.9%) had hypomagnesemia, and 12 (1.3%) had hypermagnesemia. The mortality rate in hypocalcemia group was 24% while in patients with normal calcium level it was 12%, p = 0.001. Proportionate mortality rates in hypomagnesemia and normal magnesium groups were 15% and 23% (p = 0.006), respectively. On the other hand, 7 out of 12 (58%) hypermagnesemia patients died during the index hospitalization. The regression model including GCS, ISS, PT, aPTT, INR, Hemoglobin, Bicarbonate, Lactate, Sodium, Potassium, Calcium, Magnesium, and Phosphate showed that hypocalcemia was not a significant predictor [OR 0.59 (CI 95%: 0.20–1.35)] of mortality after TBI. However, hypermagnesemia was a significant predictor [OR 16 (CI 95%: 2.1–111)] in addition to the GCS, ISS, aPTT, Bicarbonate, and Lactate values on admission. Conclusion: Although hypocalcemia and hypomagnesemia are common in hospitalized TBI patients, hypocalcemia was not a significant predictor of mortality, while hypermagnesemia was an independent predictor. Further studies with larger sample size and with prospective design are required to support these findings and their importance.

Thermoresponsive shear-thinning hydrogel (T-STH) hemostats for minimally invasive treatment of external hemorrhages

Hemorrhage is the leading cause of death following battlefield injuries. Although several hemostats are commercially available, they do not meet all the necessary requirements to stop bleeding in combat injuries. Here, we engineer thermoresponsive shear-thinning hydrogels (T-STH) composed of a thermoresponsive polymer, poly(N-isopropyl acrylamide) (p(NIPAM)), and hemostatic silicate nanodisks, LAPONITE®, as minimally invasive injectable hemostatic agents. Our T-STH is a physiologically stable hydrogel that can be easily injected through a syringe and needle and exhibits rapid mechanical recovery. Additionally, it demonstrates temperature-dependent blood coagulation owing to the phase transition of p(NIPAM). It decreases in vitro blood clotting times over 50% at physiological temperatures compared to room temperature. Furthermore, it significantly prevents blood loss in an ex vivo bleeding model at different blood flow rates (1 mL min^-1 and 5 mL min^-1) by forming a wound plug. More importantly, our T-STH is comparable to a commercially available hemostat, Floseal, in terms of blood loss and blood clotting time in an in vivo rat liver bleeding model. Furthermore, once the hemorrhage is stabilized, our T-STH can be easily removed using a cold saline wash without any rebleeding or leaving any residues. Taken together, our T-STH can be used as a first aid hemostat to treat external hemorrhages in emergency situations.

Efficacy and safety of CounterFlow in animal models of hemorrhage

LAY SUMMARY

The efficacy of current hemostatic technologies is limited by several factors. Outward blood flow washes hemostatic drugs away from the wound, and hemostatic drugs often require focus, training, and time to use correctly, are highly specific to one type of injury, or pose severe safety risks. CounterFlow is a novel product that could potentially save military and civilian lives by stopping heavy bleeding from a variety of organs and other bodily locations that current technology cannot easily treat. Upon contact with blood, CounterFlow releases bursts of gas to safely self-propel bio-degradable clot-forming and clot-stabilizing drugs against blood flow, delivering them to the source of bleeding. This unique mechanism allows CounterFlow to be applied quickly to a wide assortment of wounds and to act effectively with little management after application. CounterFlow was tested in multiple animal models representing common and deadly bleeding scenarios, including internal bleeding, care under fire without compression, and surgical bleeding, and it was found to outperform current care options by stopping bleeds faster and increasing survival times. CounterFlow is also safe to use and biocompatible. This narrative review summarizes studies testing the effectiveness and safety of CounterFlow, discusses useful applications, and describes future plans for the product.

Characteristics and Outcomes of Prehospital Tourniquet Use for Trauma in the United States

INTRODUCTION

The use of the extremity tourniquet in military environments has reduced preventable deaths due to exsanguinating hemorrhage, leading to increased use in civilian settings. However, the outcomes of contemporary prehospital tourniquet use in civilian settings are not well-described nationally. The objective of this study was to describe the characteristics and outcomes following prehospital tourniquet use by emergency medical services (EMS) in the United States.

METHODS

All trauma activations reported to the National EMS Information System 2019 (NEMSIS) were included. Patients who had ≥1 tourniquet applied were identified. Descriptive analyses were used to compare characteristics between tourniquet and no-tourniquet cohorts. Coarsened exact matching was performed to generate a k2k match (on age, sex, lowest-systolic blood pressure, initial patient acuity, provider's initial impression, injury mechanism, and presence of upper/lower extremity injuries) and used to compare outcomes. Trauma patients who may have potentially benefited from tourniquet application (extremity injury, shock index ≥1 and no documented tourniquet application) were identified.

RESULTS

A total of 7,161 tourniquets were applied among 4,571,379 trauma activations (1.6/1000 activations). Patients in the tourniquet cohort were younger (40 ± 18 vs 52 ± 26 mean ± SD years), more hypotensive (16.1% vs. 2.5%) and had higher initial acuity (65.0% critical/emergent vs. 20.6%) [p < 0.01 for all]. A total of 7,074 patients in the tourniquet cohort were matched with 7,074 patients in the non-tourniquet cohort. Post-match analysis revealed that the patients in tourniquet cohort had a higher final acuity (80.8% vs. 75.0%, p < 0.01), lower scene-time (15.4 ± 13.6 vs. 17.0 ± 14.2 mean ± SD minutes, p < 0.01), and higher survival-to-hospital (83.6% vs. 75.1%, p < 0.01). A total of 141,471 trauma patients who may have potentially benefited from tourniquet application were identified.

CONCLUSION

Prehospital tourniquet use by EMS in the United States is associated with lower scene-time and improved survivability to hospital. Results indicate that patients might benefit from wider tourniquet use in the civilian prehospital setting.

An observational study of the blood use in combat casualties of the French Armed Forces, 2013-2021

BACKGROUND

The French Armed Forces conduct asymmetric warfare in the Sahara-Sahel Strip. Casualties are treated with damage control resuscitation to the extent possible. Questions remain about the feasibility and sustainability of using blood for wider use in austere environments.

METHODS

We performed a retrospective analysis of all French military trauma patients transfused after injury in overseas military operations in Sahel-Saharan Strip, from the point of injury, until day 7, between January 11, 2013 to December 31, 2021.

RESULTS

Forty-five patients were transfused. Twenty-three (51%) of them required four red blood cells units (RBC) or more in the first 24H defining a severe hemorrhage. The median blood product consumption within the first 48 h, was 8 (IQR [3; 18]) units of blood products (BP) for all study population but up to 17 units (IQR [10; 27.5]) for the trauma patients with severe hemorrhage. Transfusion started at prehospital stage for 20 patients (45%) and included several blood products: French lyophilized plasma, RBCs, and whole blood. Patients with severe hemorrhage required a median of 2 [IQR 0; 34] further units of BP from day 3 to day 7 after injury. Eight patients died in theater, 4 with severe hemorrhage and these 4 used an average of 12 products at Role 1 and 2.

CONCLUSION

The transfusion needs were predominant in the first 48 h after the injury but also continued throughout the first week for the most severe trauma patients. Importantly, our study involved a low-intensity conflict, with a small number of injured combatants.

Effects of sequential aeromedical evacuations following traumatic brain injury in swine

INTRODUCTION

Traumatic brain injuries (TBI) represent a significant percentage of critical injuries in military conflicts. Following injury, wounded warfighters are often subjected to multiple aeromedical evacuations (AE) and associated hypobaria, yet the impact in TBI patients remains to be characterized. This study evaluated the impact of two consecutive simulated AEs in a fluid-percussion TBI model in swine to characterize these effects.

METHODS

Following instrumentation, anesthetized Yorkshire swine underwent a frontal TBI via fluid-percussion. A hypobaric chamber was then used to simulate AE at simulated cabin pressure equivalent to 8000ft (hypobaria) in a 6 h initial flight on day 3, followed by a 9 h flight on day 6, and were monitored for 14 days. Animals in the normobaria group were subjected to the same steps at sea level while Sham animals in both groups were instrumented but not injured. Parameters measured included physiologic response, intracranial pressure (ICP), hematology, chemistry, and serum cytokines. Histopathology of brain, lung, intestine, and kidney was performed, as well as fluorojade staining to evaluate neurodegeneration. All animals were divided into sub-groups by block randomization utilizing a 2-way ANOVA to analyze independent variables.

RESULTS

Survival was 100% in all groups. Physiologic parameters were largely similar across groups as well during both 6 and 9 h AE. Animals exposed to hypobaria in both the TBI and Sham groups had elevated heart rate (HR) during the 6 h flight (p<0.05). Three animals in the TBI hypo group demonstrated leukocytosis with histologic evidence of meningeal inflammatory response. Expression of serum cytokines was low across all groups. No significant neuronal degeneration was identified in areas away from the site of injury.

CONCLUSION

Aeromedical evacuation in swine was not associated with significant differences in physiologic measures, cytokine expression or levels of neuronal degeneration. Histological examination revealed higher risk of meningeal inflammatory response and leucocytosis in swine exposed to hypobaria.

John J, Khademhosseini A. Recent advances in biopolymer-based hemostatic materials

Hemorrhage is the leading cause of trauma-related deaths, in hospital and prehospital settings. Hemostasis is a complex mechanism that involves a cascade of clotting factors and proteins that result in the formation of a strong clot. In certain surgical and emergency situations, hemostatic agents are needed to achieve faster blood coagulation to prevent the patient from experiencing a severe hemorrhagic shock. Therefore, it is critical to consider appropriate materials and designs for hemostatic agents. Many materials have been fabricated as hemostatic agents, including synthetic and naturally derived polymers. Compared to synthetic polymers, natural polymers or biopolymers, which include polysaccharides and polypeptides, have greater biocompatibility, biodegradability and processibility. Thus, in this review, we focus on biopolymer-based hemostatic agents of different forms, such as powder, particles, sponges and hydrogels. Finally, we discuss biopolymer-based hemostatic materials currently in clinical trials and offer insight into next-generation hemostats for clinical translation.

Management of conflict injuries to the upper limb. Part 1: assessment and early surgical care

Upper limb injuries are common in conflict zones. The functions of the upper limb are impossible to replicate with prosthetic replacement and wherever possible attempts should be made to preserve the limb with further secondary reconstruction aimed at restoration of function. Casualty assessment, haemorrhage control and resuscitation are simultaneously undertaken at the receiving medical facility. Primary surgical management involves decontamination and debridement, skeletal stabilization, restoration of vascularity, compartment fasciotomy where indicated and wound temporization with dressings. Operative findings and interventions should be documented and if evacuation of the casualty is possible, copies should be provided in the medical records to facilitate communication in the chain of care. Secondary procedures are required for further assessment and debridement prior to planning reconstruction and definitive fracture stabilization, nerve repair, wound cover or closure.

Effect of special operational forces surgical resuscitation teams on combat casualty survival: A narrative review

IMPORTANCE

The most common cause of preventable death on the conventional battlefield or on special operations force (SOF) missions is hemorrhage. SOF missions may take place in remote and austere locations. Many preventable deaths in combat occur within 30 min of wounding. Therefore, SOF damage control resuscitation (DCR) and damage control surgery (DCS) teams may improve combat casualty survival in the SOF environment.

OBJECTIVE

To determine the effect of SOF DCR and DCS teams on combat casualty survival. Also, to describe commonalities in team structure, logistics, and blood product usage.

DESIGN

A narrative review of the English literature used a Medline and Embase search strategy. The authors were contacted for more details as required. The risk of bias was assessed using the Cochrane Collaboration's ROBINS-I tool. Pooling of data was not done to the heterogeneity of studies.

RESULTS

Weak evidence was identified showing a clinical benefit of SOF DCR and DCS teams. Conflicting evidence from less rigorous studies was also found. The overall risk of bias using ROBINS-I was serious to critical. Several commonalities in team structure, training, and logistics were found.

CONCLUSIONS AND RELEVANCE

There is conflicting evidence regarding the effect SOF DCR and DCS teams have on combat casualty survival. There is no strong evidence that SOF DCR and DCS teams cause harm. More robust data collection is recommended to evaluate these teams.

Resuscitative endovascular balloon occlusion of the aorta management guided by a novel handheld pressure transducer

BACKGROUND

Management of noncompressible truncal hemorrhage using resuscitative endovascular balloon occlusion of the aorta (REBOA) requires arterial pressure monitoring that can be logistically challenging in austere or emergency settings. Novel pressure transducer devices such as the Centurion Compass device (CD) (Medline, Northfield, IL) offer an alternative to traditional monitoring systems. We sought to assess the feasibility of maintaining permissive hypotension during intermittent REBOA in a porcine model guided by CD monitoring.

METHODS

Eight Yorkshire swine underwent 20% hemorrhage with an uncontrolled iliofemoral vascular injury. Time-based intermittent zone 1 REBOA was performed with volume-based resuscitation to maintain permissive hypotension. Proximal mean arterial pressures (MAPs) from a carotid arterial line (AL) were obtained and compared with CD readings from the proximal REBOA port. The operator was blinded to AL MAP, and the REBOA was managed with exclusively the CD.

RESULTS

Mean survival time was 100 minutes (range, 41-120 minutes) from injury. Arterial line and CD measurements were closely correlated (r = 0.94, p < 0.001). Bland-Altman analysis for comparison of clinical measurements demonstrated a mean difference of 6 mm Hg (95% confidence interval, -22 to 34 mm Hg) for all MAPs, with a mean difference of 3 mm Hg (95% confidence interval, -6 to 12 mm Hg) in a clinically relevant MAP of <65 mm Hg subset.

CONCLUSION

The CD represents a miniaturized and portable arterial pressure monitor that provides an accurate alternative to logistically burdensome AL monitoring to guide REBOA use. The device is highly accurate even at hypotensive pressures and can be used to guide intermittent REBOA strategies.

Advanced partial occlusion controller allows for increased precision during targeted regional optimization in a porcine model of hemorrhagic shock

BACKGROUND

Targeted regional optimization (TRO), a partial resuscitative endovascular balloon occlusion of the aorta strategy, may mitigate distal ischemia and extend the window of effectiveness for this adjunct. An automated device may allow greater control and precise regulation of flow past the balloon, while being less resource-intensive. The objective of this study was to assess the technical feasibility of the novel advanced partial occlusion controller (APOC) in achieving TRO at multiple distal pressures.

METHODS

Female swine (n = 48, 68.1 ± 0.7 kg) were randomized to a target distal mean arterial pressure (MAP) of 25 mm Hg, 35 mm Hg, or 45 mm Hg by either manual (MAN) or APOC regulation (n = 8 per group). Uncontrolled hemorrhage was generated by liver laceration. Targeted regional optimization was performed for 85 minutes, followed by surgical control and a 6-hour critical care phase. Proximal and distal MAP and flow rates were measured continuously.

RESULTS

At a target distal MAP of 25 mm Hg, there was no difference in the MAP attained (APOC: 26.2 ± 1.05 vs. MAN: 26.1 ± 1.78 mm Hg) but the APOC had significantly less deviance (10.9%) than manual titration (14.9%, p < 0.0001). Similarly, at a target distal MAP of 45 mm Hg, there was no difference in mean pressure (44.0 ± 0.900 mm Hg vs. 45.2 ± 1.31 mm Hg) but APOC had less deviance (9.34% vs. 11.9%, p < 0.0001). There was no difference between APOC and MAN in mean (34.6 mm Hg vs. 33.7 mm Hg) or deviance (9.95% vs. 10.4%) at a target distal MAP of 35 mm Hg, respectively. The APOC made on average 77 balloon volume adjustments per experiment compared with 29 by manual titrations.

CONCLUSION

The novel APOC consistently achieved and sustained precisely regulated TRO across all groups and demonstrated reduced deviance at the 25 mm Hg and 45 mm Hg groups compared with manual titration.