Qualitative investigation of military surgical resuscitation teams: what are the drivers of success of a rapid response team?

OBJECTIVES: This qualitative study explores the characteristics of a specialised military medical rapid response team (MRRT), the surgical resuscitation team (SRT). Despite mixed evidence of efficacy, civilian MRRTs are widely employed, with significant variation in structure and function. Recent increased use of these teams to mitigate patient risk in challenging healthcare scenarios, such as global pandemics, mass casualty events and resource-constrained health systems, mandates a reconceptualisation of how civilian MRRTs are created, trained and used. Here, we study the core functions and foundational underpinnings of SRTs and discuss how civilian MRRTs might learn from their military counterparts. DESIGN: Semistructured interview-based study using Descriptive Qualitative Research methodology and Thematic Analysis. SETTING: Remote audio interviews conducted via Zoom. PARTICIPANTS: Participants included 15 members of the United States Special Operations Command SRTs, representing all medical specialties of the SRT as well as operational planners. RESULTS: Adaptability was identified as a core function of SRTs and informed by four foundational underpinnings: mission variability, shared values and principles, interpersonal and organisational trust and highly effective teaming. Our findings provide three important insights for civilian MRRTs: (1) team member roles should not be defined by silos of professional specialisation, (2) trust is a key factor in the teaming process and (3) team principles and values result in and are reinforced by organisational trust. CONCLUSION: This study offers the first in-depth investigation of a unique military MRRT. Important insights that may offer benefit to civilian MRRT practices include enabling the breakdown of traditional division of labour, allowing for and promoting deep interpersonal and professional familiarity, and facilitating a cycle of positive reinforcement between teams and organisations. Future investigation of small team limitations, comparability to civilian MRRTs, and the team relationship to the larger organisation are needed to better understand how these teams function in a healthcare system and translate to civilian practice.

Developing the Ready Military Medical Force: military-specific training in Graduate Medical Education.

Introduction: Graduate Medical Education plays a critical role in training the next generation of military physicians, ensuring they are ready to uphold the dual professional requirements inherent to being both a military officer and a military physician. This involves executing the operational duties as a commissioned leader while also providing exceptional medical care in austere environments and in harm's way. The purpose of this study is to review prior efforts at developing and implementing military unique curricula (MUC) in residency training programs. Methods: We performed a literature search in PubMed (MEDLINE), Embase, Web of Science, and the Defense Technical Information Center through August 8, 2023, including terms "graduate medical education" and "military." We included articles if they specifically addressed military curricula in residency with terms including "residency and operational" or "readiness training", "military program", or "military curriculum". Results: We identified 1455 articles based on title and abstract initially and fully reviewed 111. We determined that 64 articles met our inclusion criteria by describing the history or context of MUC, surveys supporting MUC, or military programs or curricula incorporated into residency training or military-specific residency programs. Conclusion: We found that although there have been multiple attempts at establishing MUC across training programs, it is difficult to create a uniform curriculum that can be implemented to train residents to a single standard across services and specialties.

Engineering Human Cells Expressing CRISPR/Cas9-Synergistic Activation Mediators for Recombinant Protein Production.

Recombinant engineering for protein production commonly employs plasmid-based gene templates for introduction and expression of genes in a candidate cell system in vitro. Challenges to this approach include identifying cell types that can facilitate proper post-translational modifications and difficulty expressing large multimeric proteins. We hypothesized that integration of the CRISPR/Cas9-synergistic activator mediator (SAM) system into the human genome would be a powerful tool capable of robust gene expression and protein production. SAMs are comprised of a "dead" Cas9 (dCas9) linked to transcriptional activators viral particle 64 (VP64), nuclear factor-kappa-B p65 subunit (p65), and heat shock factor 1 (HSF1) and are programmable to single or multiple gene targets. We integrated the components of the SAM system into human HEK293, HKB11, SK-HEP1, and HEP-g2 cells using coagulation factor X (FX) and fibrinogen (FBN) as proof of concept. We observed upregulation of mRNA in each cell type with concomitant protein expression. Our findings demonstrate the capability of human cells stably expressing SAM for user-defined singleplex and multiplex gene targeting and highlight their broad potential utility for recombinant engineering as well as transcriptional modulation across networks for basic, translational, and clinical modeling and applications.

Committee on Surgical Combat Casualty Care position statement: Neurosurgical capability for the optimal management of traumatic brain injury during deployed operations.

BACKGROUND: Experiences over the last three decades of war have demonstrated a high incidence of traumatic brain injury (TBI) resulting in a persistent need for a neurosurgical capability within the deployed theater of operations. Despite this, no doctrinal requirement for a deployed neurosurgical capability exists. Through an iterative process, the Joint Trauma System Committee on Surgical Combat Casualty Care (CoSCCC) developed a position statement to inform medical and nonmedical military leaders about the risks of the lack of a specialized neurosurgical capability. METHODS: The need for deployed neurosurgical capability position statement was identified during the spring 2021 CoSCCC meeting. A triservice working group of experienced forward-deployed caregivers developed a preliminary statement. An extensive iterative review process was then conducted to ensure that the intended messaging was clear to senior medical leaders and operational commanders. To provide additional context and a civilian perspective, statement commentaries were solicited from civilian clinical experts including a recently retired military trauma surgeon boarded in neurocritical care, a trauma surgeon instrumental in developing the Brain Injury Guidelines, a practicing neurosurgeon with world-renowned expertise in TBI, and the chair of the Committee on Trauma. RESULTS: After multiple revisions, the position statement was finalized, and approved by the CoSCCC membership in February 2023. Challenges identified include (1) military neurosurgeon attrition, (2) the lack of a doctrinal neurosurgical capabilities requirement during deployed combat operations, and (3) the need for neurosurgical telemedicine capability and in-theater computed tomography scans to triage TBI casualties requiring neurosurgical care. CONCLUSION: Challenges identified regarding neurosurgical capabilities within the deployed trauma system include military neurosurgeon attrition and the lack of a doctrinal requirement for neurosurgical capability during deployed combat operations. To mitigate risk to the force in a future peer-peer conflict, several evidence-based recommendations are made. The solicited civilian commentaries strengthen these recommendations by putting them into the context of civilian TBI management. This neurosurgical capabilities position statement is intended to be a forcing function and a communication tool to inform operational commanders and military medical leaders on the use of these teams on current and future battlefields. LEVEL OF EVIDENCE: Prognostic and Epidemiological; Level V.

Airborne! UAV delivery of blood products and medical logistics for combat zones.

BACKGROUND: Innovative solutions to resupply critical medical logistics and blood products may be required in future near-peer conflicts. Unmanned aerial vehicles (UAVs) are increasingly being used in austere environments and may be a viable platform for medical resupply and the transport of blood products. METHODS: A literature review on PubMed and Google Scholar up to March of 2022 yielded a total of 27 articles that were included in this narrative review. The objectives of this article are to discuss the current limitations of prehospital blood transfusion in military settings, discuss the current uses of UAVs for medical logistics, and highlight the ongoing research surrounding UAVs for blood product delivery. DISCUSSION: UAVs allow for the timely delivery of medical supplies in numerous settings and have been utilized for both military and civilian purposes. Investigations into the effects of aeromedical transportation on blood products have found minimal blood product degradation when appropriately thermoregulated and delivered in a manner that minimizes trauma. UAV delivery of blood products is now actively being explored by numerous entities around the globe. Current limitations surrounding the lack of high-quality safety data, engineering constraints over carrying capacity, storage capability, and distance traveled, as well as air space regulations persist. CONCLUSION: UAVs may offer a novel solution for the transport of medical supplies and blood products in a safe and timely manner for the forward-deployed setting. Further research on optimal UAV design, optimal delivery techniques, and blood product safety following transport should be explored prior to implementation.

Validation of a miniaturized handheld arterial pressure monitor for guiding full and partial REBOA use during resuscitation.

PURPOSE: Resuscitative endovascular balloon occlusion of the aorta (REBOA) is a well-validated method for the control of noncompressible truncal hemorrhage. In lower resource or battlefield settings, the need for arterial line setup and monitoring is problematic and potentially prohibitive. We sought to evaluate the accuracy and precision of a miniaturized portable device (Centurion COMPASS®) versus standard arterial pressure monitoring using standard ER-REBOA and partial REBOA (pREBOA) as a high-fidelity and space-/time-conserving alternative. METHODS: A total of 40 swine underwent a four-phase validation/precision study (each phase using five ER-REBOAs and five pREBOAs). Phases I/II evaluated accuracy with full and pREBOA in uninjured animals. Phases III/IV duplicated the previous phases but in a severe hemorrhagic shock model. Carotid and femoral pressures were monitored with both intra-arterial pressure systems and the COMPASS® device. The vascular flow was measured by aortic flow probes. Correlation and Bland-Altman analysis were performed. RESULTS: There was a strong correlation in accuracy testing of proximal and distal COMPASS® devices compared to standard intra-arterial pressure monitoring (r = 0.94, 0.8; p < 0.005) as well as during precision testing (r = 0.98, 0.89 p < 0.005) in the uninjured phases. Similar accuracy and reliability were demonstrated in hemorrhagic shock, with a strong correlation for the proximal and distal COMPASS® devices (r = 0.98, 0.97; p < 0.005), as well as during precision testing (r = 0.99, 0.95; p < 0.005) in both full and pREBOA scenarios. Bland-Altman analysis showed extremely low bias between the COMPASS® and arterial line for both proximal (bias = 1.9) and distal (bias = 0.8) pressure measurements. CONCLUSION: The COMPASS® provides accurate and precise pressure measurements during standard and partial REBOA in both uninjured and shock conditions. This device may help extend and enhance capability in any low-resource/battlefield settings, or even eliminate the need for standard intra-arterial invasive pressure monitoring and external setup.

Committee on Surgical Combat Casualty Care position statement on the use of single surgeon teams and invited commentaries.

BACKGROUND: Over the last 20 years of war, there has been an operational need for far forward surgical teams near the point of injury. Over time, the medical footprint of these teams has decreased and the utilization of mobile single surgeon teams (SSTs) by the Services has increased. The increased use of SSTs is because of a tactical mobility requirement and not because of proven noninferiority of clinical outcomes. Through an iterative process, the Committee on Surgical Combat Casualty Care (CoSCCC) reviewed the utilization of SSTs and developed an expert-opinion consensus statement addressing the risks of SST utilization and proposed mitigation strategies. METHODS: A small triservice working group of surgeons with deployment experience, to include SST deployments, developed a statement regarding the risks and benefits of SST utilization. The draft statement was reviewed by a working group at the CoSCCC meeting November 2021 and further refined. This was followed by an extensive iterative review process, which was conducted to ensure that the intended messaging was clear to senior medical leaders and operational commanders. The final draft was voted on by the entire CoSCCC membership. To inform the civilian trauma community, commentaries were solicited from civilian trauma leaders to help put this practice into context and to further the discussion in both military and civilian trauma communities. RESULTS: After multiple revisions, the SST statement was finalized in January 2022 and distributed to the CoSCCC membership for a vote. Of 42 voting members, there were three nonconcur votes. The SST statement underwent further revisions to address CoSCCC voting membership comments. Statement commentaries from the President of the American Association for the Surgery for Trauma, the chair of the Committee on Trauma, the Medical Director of the Military Health System Strategic Partnership with the American College of Surgeons and a recently retired military surgeon we included to put this military relevant statement into a civilian context and further delineate the risks and benefits of including the trauma care paradigm in the Department of Defense (DoD) deployed trauma system. CONCLUSION: The use of SSTs has a role in the operational environment; however, operational commanders must understand the tradeoff between tactical mobility and clinical capabilities. As SST tactical mobility increases, the ability of teams to care for multiple casualty incidents or provide sustained clinical operations decreases. The SST position statement is a communication tool to inform operational commanders and military medical leaders on the use of these teams on current and future battlefields.

Engineering CRISPR/Cas9 for Multiplexed Recombinant Coagulation Factor Production.

Current hemostatic agents are obtained from pooled plasma from multiple donors requiring costly pathogen screening and processing. Recombinant DNA-based production represents an engineering solution that could improve supply, uniformity, and safety. Current approaches are typically for single gene candidate peptides and often employ non-human cells. We devised an approach where multiple gene products could be produced from a single population of cells. We identified gene specific Synergistic Activation Mediators (SAM) from the CRISPR/Cas9 system for targeted overexpression of coagulation factors II, VII, IX, X, and fibrinogen. The components of the CRISPR-SAM system were expressed in Human Embryonic Kidney Cells (HEK293), and single (singleplex) or multi-gene (multiplex) upregulation was assessed by quantitative RT-PCR (qRT-PCR) and protein expression by ELISA analysis. Factor II, VII, IX, and X singleplex and multiplex activation resulted in 120-4700-fold and 60-680-fold increases in gene expression, respectively. Fibrinogen sub-unit gene activation resulted in a 1700-92,000-fold increases and 80-5500-fold increases in singleplex or multiplex approaches, respectively. ELISA analysis showed a concomitant upregulation of candidate gene products. Our findings demonstrate the capability of CRISPR/Cas9 SAMs for single or multi-agent production in human cells and represent an engineering advance that augments current recombinant peptide production techniques.

Adenosine, lidocaine, and magnesium for attenuating ischemia reperfusion injury from resuscitative endovascular balloon occlusion of the aorta in a porcine model.

BACKGROUND: Minimally invasive resuscitative endovascular balloon occlusion of the aorta (REBOA) following noncompressible hemorrhage results in significant ischemia reperfusion injury (IRI). Adverse outcomes from IRI include organ dysfunction and can result in profound hemodynamic and molecular compromise. We hypothesized that adenosine, lidocaine, and magnesium (ALM) attenuates organ injury and inflammation responses following REBOA IRI in a porcine model of hemorrhage. METHODS: Animals underwent a 20% controlled hemorrhage followed by 45 minutes of supraceliac balloon occlusion. They were randomized into two groups: control (n = 9) and ALM intervention (n = 9) to include a posthemorrhage, pre-REBOA bolus (200 mL of 3% NaCl ALM) followed by a continuous drip (2 mL/kg per hour of 0.9% NaCl ALM) during the 4-hour resuscitative period. Primary outcomes included hemodynamic parameters, gene expression of inflammatory signaling molecules, and plasma concentrations of select cytokines and chemokines. RESULTS: The ALM cohort demonstrated a significant reduction in cardiac output and cardiac index. Plasma concentrations of interleukin 2 and interleukin 10 were significantly lower 3 hours post-REBOA in animals treated with ALM versus vehicle. Interleukin 4 levels in plasma were also lower with ALM at 3 and 4 hours post-REBOA (p < 0.05). Liver expression of IL1RN, MTOR, and LAMP3 messenger RNA was significantly lower with ALM as compared with the vehicle. No significant difference in large bowel gene expression was observed between treatments. CONCLUSION: In a porcine model of hemorrhage, ALM treatment mitigated inflammatory responses early during post-REBOA resuscitation. Our findings suggest that ALM use with trauma may reduce inflammatory injury and improve outcomes related to REBOA utilization.

Addition of neurological status to pediatric adjusted shock index to predict early mortality in trauma: A pediatric Trauma Quality Improvement Program analysis.

INTRODUCTION: Pediatric adjusted shock index (SIPA) has demonstrated the ability to prospectively identify children at the highest risk for early mortality. The addition of neurological status to shock index has shown promise as a reliable triage tool in adult trauma populations. This study sought to assess the utility of combining SIPA with Glasgow Coma Scale (GCS) for predicting early trauma-related outcomes. METHODS: Retrospective review of the 2017 Trauma Quality Improvement Program Database was performed for all severely injured patients younger than 18 years old. Pediatric adjusted shock index and reverse SIPA × GCS (rSIG) were calculated. Age-specific cutoff values were derived for reverse shock index multiplied by GCS (rSIG) and compared with their SIPA counterparts for early mortality assessment using area under the receiver operating characteristic curve analyses. RESULTS: A total of 10,389 pediatric patients with an average age of 11.4 years, 67% male, average Injury Severity Score of 24.1, and 4% sustaining a major penetrating injury were included in the analysis. The overall mortality was 9.3%. Furthermore, 32.1% of patients displayed an elevated SIPA score, while only 27.5% displayed a positive rSIG. On area under the receiver operating characteristic curve analysis, rSIG was found to be superior to SIPA as a predictor for in hospital mortality with values of 0.854 versus 0.628, respectively. CONCLUSION: Reverse shock index multiplied by GCS more readily predicted in hospital mortality for pediatric trauma patients when compared with SIPA. These findings suggest that neurological status should be an important factor during initial patient assessment. Further study to assess the applicability of rSIG for expanded trauma-related outcomes in pediatric trauma is necessary. LEVEL OF EVIDENCE: Prognostic study, level IV.

A Surgeon's Guide to Machine Learning.

Machine learning (ML) represents a collection of advanced data modeling techniques beyond the traditional statistical models and tests with which most clinicians are familiar. While a subset of artificial intelligence, ML is far from the science fiction impression frequently associated with AI. At its most basic, ML is about pattern finding, sometimes with complex algorithms. The advanced mathematical modeling of ML is seeing expanding use throughout healthcare and increasingly in the day-to-day practice of surgeons. As with any new technique or technology, a basic understanding of principles, applications, and limitations are essential for appropriate implementation. This primer is intended to provide the surgical reader an accelerated introduction to applied ML and considerations in potential research applications or the review of publications, including ML techniques.

Pediatric adjusted reverse shock index multiplied by Glasgow Coma Scale as a prospective predictor for mortality in pediatric trauma.

INTRODUCTION: Shock index and its pediatric adjusted derivative (pediatric age-adjusted shock index [SIPA]) have demonstrated utility as prospective predictors of mortality in adult and pediatric trauma populations. Although basic vital signs provide promise as triage tools, factors such as neurologic status on arrival have profound implications for trauma-related outcomes. Recently, the reverse shock index multiplied by Glasgow Coma Scale (GCS) score (rSIG) has been validated in adult trauma as a tool combining early markers of physiology and neurologic function to predict mortality. This study sought to compare the performance characteristics of rSIG against SIPA as a prospective predictor of mortality in pediatric war zone injuries. METHODS: Retrospective review of the Department of Defense Trauma Registry, 2008 to 2016, was performed for all patients younger than 18 years with documented vital signs and GCS on initial arrival to the trauma bay. Optimal age-specific cutoff values were derived for rSIG via the Youden index using receiver operating characteristic analyses. Multivariate logistic regression was performed to validate accuracy in predicting early mortality. RESULTS: A total of 2,007 pediatric patients with a median age range of 7 to 12 years, 79% male, average Injury Severity Score of 11.9, and 62.5% sustaining a penetrating injury were included in the analysis. The overall mortality was 7.1%. A total of 874 (43.5%) and 685 patients (34.1%) had elevated SIPA and pediatric rSIG scores, respectively. After adjusting for demographics, mechanism of injury, initial vital signs, and presenting laboratory values, rSIG (odds ratio, 4.054; p = 0.01) was found to be superior to SIPA (odds ratio, 2.742; p < 0.01) as an independent predictor of early mortality. CONCLUSION: Reverse shock index multiplied by GCS score more accurately identifies pediatric patients at highest risk of death when compared with SIPA alone, following war zone injuries. These findings may help further refine early risk assessments for patient management and resource allocation in constrained settings. Further validation is necessary to determine applicability to the civilian population. LEVEL OF EVIDENCE: Prognostic study, level IV.

Safety code blue! Assessing the use of blue surgical sterilization wrap for homemade respirator masks during the COVID-19 crisis.

The use of surgical sterilization wrap for respirator masks during the COVID-19 crisis has become a popularized personal protective equipment alternative option due to claims supporting its ability to meet N95 standards. This study sought to assess these claims using standardized filter testing. The tested material failed to meet N95 standards and suggests its use may place medical personnel at increased risk of harm when managing COVID-19 patients.

Dynamic trend or static variable: Shock Index Pediatric-Adjusted (SIPA) in warzone trauma.

BACKGROUND: Civilian studies suggest that trending Shock-Index Pediatric Adjusted(SIPA) values can prove useful in the prediction of trauma outcomes. The purpose of this study was to evaluate the relationship between trends in SIPA and outcomes in pediatric warzone trauma. METHODS: Retrospective review of the Department of Defense Trauma Registry from 2008 to 2015, including all patients age ≤17years. SIPA was calculated both pre-hospital and upon arrival, then classified as "normal" or "abnormal" based upon previously validated thresholds. Patients were stratified into groups based on the trend of their SIPA (1-normal to normal, 2-normal to abnormal, 3-abnormal to normal, 4-abnormal to abnormal). Key outcomes including ICU admission, severe injury, mechanical ventilation, and mortality were then compared between groups. RESULTS: 669 patients were included, mean ISS 12 ± 10. The most common mechanism of injury was blast (46.5%). Overall, 43% were stratified into Group 1, 13.9% into Group 2, 14.8% into Group 3, and 28.0% into Group 4. Those patients with a persistently abnormal SIPA (Group 4) had significantly increased incidence of severe injury, ICU admission, need for mechanical ventilation, and mortality. CONCLUSION: Trends in SIPA may be used to predict trauma outcomes for children injured in warzones, with persistently abnormal values associated with worse outcomes overall.

Quality Assurance During a Global Pandemic: An Evaluation of Improvised Filter Materials for Healthcare Workers.

OBJECTIVE: The proliferation of improvised masks during the COVID-19 pandemic has raised questions regarding filter effectiveness and safety. We sought to compare the effectiveness of commonly used improvised filter materials against N95 industry standards. METHODS: Six different filter materials commonly used in the community were tested using both single- and multi-layer configurations with the TSI 8130 automated filter tester in accordance with National Institute for Occupational Safety and Health (NIOSH) standards for N95 respirators. RESULTS: Only three of the tested filter material configurations met N95 parameters with regard to filtration efficiency and pressure drop across the filter material-the: True-high-efficiency particulate air (HEPA) filter, four-layer MERV 13 and 14 HVAC filters. CONCLUSIONS: Many proposed filter materials for improvised masks do not meet current industry standards and may pose safety and efficacy concerns. Care should be taken when selecting materials for this critical respirator component, particularly for health care workers or others at high risk for pathogen exposure.

Shock Index as a Predictor of Massive Transfusion and Emergency Surgery on the Modern Battlefield.

BACKGROUND: Shock Index (SI) has been used to predict the need for massive transfusion (MT) and emergency surgical procedures (ESP) in civilian trauma. We hypothesize that SI can reliably identify combat trauma patients that will require MT and ESP when applied to the resource-constrained, combat environment. METHODS: A retrospective review was performed within the Department of Defense Trauma Registry (2008-2016). SI was calculated using heart rate and systolic blood pressure on arrival to the initial facility with surgical capabilities. A threshold value of 0.8 was used to stratify patients into two groups (Group I, SI < 0.8; and Group II, SI ≥ 0.8). The need for MT, ESP, and mortality was compared. Regression analyses were conducted to determine the independent association of SI with MT and ESP. RESULTS: A total of 4008 patients were included. The mean age of the patients was 25.5 y, and the majority were predominately male (98%). Mechanisms of injury were blunt and blast injury (62%), penetrating injury (36.7%), and burn injury (0.5%). Overall, 77% of patients (n = 3070) were stratified to Group I, and 23% of patients (n = 938) were stratified to Group II, by SI. Group II patients had a significantly greater need for MT (8.4% versus 0.4%) and ESP (30.7% versus 6.5%), both P < 0.001. Regression analysis controlling for age, gender, Injury Severity Score, and Glasgow Coma Score confirmed that SI ≥ 0.8 was an independent risk factor for both MT and need for ESPs (P < 0.001). CONCLUSIONS: SI is a significant predictor of the need for MT and ESPs in the military trauma population, representing a simple and potentially potent tool for triage and prediction of resource consumption in the resource-limited, austere setting.

Validation of a novel partial resuscitative endovascular balloon occlusion of the aorta device in a swine hemorrhagic shock model: Fine tuning flow to optimize bleeding control and reperfusion injury.

OBJECTIVES: Partial restoration of aortic flow during resuscitative endovascular balloon occlusion of the aorta (REBOA) is advocated by some to mitigate distal ischemia. Our laboratory has validated the mechanics and optimal partial REBOA (pREBOA) flow rates using a prototype device. We hypothesize that pREBOA will increase survival when compared with full REBOA (fREBOA) in prolonged nonoperative management of hemorrhagic shock. METHODS: Twenty swine underwent placement of aortic flow probes, zone 1 REBOA placement, and 20% blood volume hemorrhage. They were randomized to either solid organ or abdominal vascular injury. The pREBOA arm (10 swine) underwent full inflation for 10 minutes and then deflation to a flow rate of 0.5 L/min for 2 hours. The fREBOA arm (10 swine) underwent full inflation for 60 minutes, followed by deflation/resuscitation. The primary outcome is survival, and secondary outcomes are serologic/pathologic signs of ischemia-reperfusion injury and quantity of hemorrhage. RESULTS: Two of 10 swine survived in the fREBOA group (2/5 solid organ injury; 0/5 abdominal vascular injury), whereas 7 of 10 swine survived in the pREBOA group (3/5 solid organ injury, 4/5 abdominal vascular injury). Survival was increased (p = 0.03) and hemorrhage was higher in the pREBOA group (solid organ injury, 1.36 ± 0.25 kg vs. 0.70 ± 0.33 kg, p = 0.007; 0.86 ± 0.22 kg vs. 0.71 ± 0.28 kg, not significant). Serum evidence of ischemia was greater with fREBOA, but this was not significant (e.g., lactate, 16.91 ± 3.87 mg/dL vs. 12.96 ± 2.48 mg/dL at 120 minutes, not significant). Swine treated with pREBOA that survived demonstrated trends toward lower alanine aminotransferase, lower potassium, and higher calcium. The potassium was significantly lower in survivors at 60 minutes and 90 minutes time points (5.97 ± 0.60 vs. 7.53 ± 0.90, p = 0.011; 6.67 ± 0.66 vs. 8.15 ± 0.78, p = 0.029). Calcium was significantly higher at 30 minutes, 60 minutes, and 90 minutes (8.56 ± 0.66 vs. 7.50 ± 0.40, p = 0.034; 8.63 ± 0.62 vs. 7.15 ± 0.49, p = 0.019; 8.96 ± 0.64 vs. 7.00, p = 0.028). CONCLUSION: Prolonged pREBOA at a moderate distal flow rate provided adequate hemorrhage control, improved survival, and had evidence of decreased ischemic injury versus fREBOA. Prophylactic aggressive calcium supplementation may have utility before and during the reperfusion phase.

All trauma is not created equal: Redefining severe trauma for combat injuries.

Injury severity scores (ISS) and shock index (SI) are popular trauma scoring systems. We assessed ISS and SI in combat trauma to determine the optimal cut-off values for mortality and trauma outcomes. Retrospective analysis of the Department of Defense Trauma Registry, 2008-2016, was performed. Areas under receiver operating characteristic curves (AUROCs) were calculated for ISS and SI on mortality, massive volume transfusion (MVT), and emergent surgical procedure (ESP). Optimal cut-off values were defined using the Youden index (YI). 22,218 patients (97.1% male), median ages 25-29 years, ISS 9.4 ± 0.07, with 58.1% penetrating injury were studied. Overall mortality was 3.4%. AUROCs for ISS on mortality, MVT, and ESP were 0.882, 0.898, and 0.846, while AUROCs for SI were 0.727, 0.864, and 0.711 respectively. The optimal cut-off values for ISS on mortality, MVT, and ESP were 12.5 (YI = 0.634), 12.5 (YI = 0.666), and 12.5 (YI = 0.819), with optimal values for SI being 0.94 (YI = 0.402), 0.88 (YI = 0.608), and 0.81 (YI = 0.345) respectively. Classic values for severe ISS underrepresent combat injury while the SI values defined in this study are consistent with civilian data.

Viscoelastic testing in combat resuscitation: Is it time for a new standard?

BACKGROUND: Traumatic hemorrhage and coagulopathy represent major sources of morbidity and mortality on the modern battlefield. Viscoelastic testing (VET) offers a potentially more personalized approach to resuscitation. We sought to evaluate outcomes of combat trauma patients who received VET-guided resuscitation compared with standard balanced blood product resuscitation. METHODS: Retrospective analysis of the Department of Defense Trauma Registry, 2008 to 2016 was performed. Multivariate logistic regression analyses of all adult patients initially presenting to NATO Role III facilities who required blood products were performed to identify factors associated with VET-guided resuscitation and mortality. A propensity score matched comparison of outcomes in patient cohorts treated at VET versus non-VET Role III facilities was performed. RESULTS: There are 3,320 patients, predominately male (98%), median age ranges from 25 years to 29 years, Injury Severity Score of 18.8, with a penetrating injury (84%) were studied. Overall mortality was 9.7%. Five hundred ninety-four patients had VET during their initial resuscitation. After adjusting for confounders, VET during initial resuscitation was independently associated with decreased mortality (odds ratio, 0.63; p = 0.04). Propensity analysis confirmed this survival advantage with a 57% reduction in overall mortality (7.3% vs. 13.1%; p = 0.001) for all patients requiring blood products. CONCLUSION: Viscoelastic testing offers the possibility of a product-specific resuscitation for critically injured patients requiring transfusion in combat settings. Routine VET may be superior to non-VET-guided resuscitation for combat trauma victims. LEVEL OF EVIDENCE: Therapeutic study, level IV.