Who Says You can't go FAST at Night? Use of a Novel Ultrasound-Capable Night Vision Device for Prehospital Medical Personnel to Identify Noncompressible Truncal Hemorrhage.

BACKGROUND: Early detection of abdominal hemorrhage via ultrasound has life-saving implications for military and civilian trauma. However, strict adherence to light discipline may prohibit the use of ultrasound devices in the deployed setting. Additionally, current night vision devices remain noncompatible with ultrasound technology. This study sought to assess an innovative night vision device with ultrasound capable picture-in-picture display via a intraabdominal hemorrhage model to identify noncompressible truncal hemorrhage in blackout conditions. METHODS: 8 post mortem fetal porcine specimens were used and divided into 2 groups: intrabdominal hemorrhage (n = 4) vs no hemorrhage (n = 4). Intrabdominal hemorrhage was modeled via direct injection of 200 mL of normal saline into the peritoneal cavity. Under blackout conditions, 5 participants performed a focused assessment with sonography for trauma (FAST) exam on each model using the prototype ultrasound-capable night vision device. RESULTS: Of the 40 FAST exams performed, 95% (N = 38) resulted in the correct identification of intraabdominal hemorrhage. Of the incorrectly identified exams, both were false positives resulting in a 100% sensitivity, 90% specificity, 91% positive predictive value, and a 100% negative predictive value. All participants noted the novel device was easy to use and provided superior visualization for performing FAST exams under blackout conditions. CONCLUSION: The ultrasound-enabled night vision prototype demonstrated promising results in identifying noncompressible truncal hemorrhage while maintaining strict light discipline in blackout conditions. Further research efforts should be directed at assessing the ability of providers to perform procedures in blackout conditions using the ultrasound-enabled prototype night vision device.

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.

Blood Utilization and Thresholds for Mortality Following Major Trauma.

INTRODUCTION: Blood loss is a hallmark of traumatic injury. Massive transfusion, historically defined as the replacement by transfusion of 10 units of packed red blood cells (PRBCs) in 4 h, is a response to uncontrolled hemorrhage. We sought to identify blood transfusion thresholds in which predicted mortality exceeds 50%. METHODS: We analyzed the 2017-2019 National Trauma Database. Inclusion criteria included patients ≥18 y who received ≥1 unit of PRBCs. Statistical analysis included bivariate analysis, logistic regression for mortality, and adjusted predicted probability modeling was utilized. RESULTS: We identified 61,676 patients for analysis. The 50% predicted mortality for all patients was 31 PRBC units. The 50% predicted mortality was 6 units of PRBCs for elderly trauma patients 80 y and older. CONCLUSIONS: Blood remains as scarce resource in hospitals especially with trauma. Patients receiving a massive transfusion over a short period of time may exhaust blood bank supply with diminishing survival benefit. Surgeons should be judicious regarding continued blood usage once the 50% predicted mortality threshold is reached.

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.

Machine Learning for Military Trauma: Novel Massive Transfusion Predictive Models in Combat Zones.

BACKGROUND: Damage control resuscitation has become the standard of care in military and civilian trauma. Early identification of blood product requirements may aid in optimizing the clinical decision-making process while improving trauma related outcomes. This study aimed to assess and compare multiple machine learning models for predicting patients at highest risk for massive transfusion on the battlefield. METHODS: Supervised machine learning approaches using logistic regression, support vector machine, neural network, and random forest techniques were used to create predictive models for massive transfusion using standard prehospital and arrival data points from the Department of Defense Trauma Registry, 2008-2016. Seventy percent of the population was used for model development and performance was validated using the remaining 30%. Models were tested for accuracy and compared by standard performance statistics. RESULTS: A total of 22,158 patients (97% male, 58% penetrating injury, median age 25-29 y/o, average Injury Severity Score 9, with an overall mortality of 3%) were included in the analysis. Massive transfusion was required by 7.4% of patients. Overall accuracy was found to be above 90% in all models tested. Following cross validation and model training, the random forest model outperformed the alternatively tested models for precision, recall, and area under the curve. CONCLUSION: Machine learning techniques may allow for more optimal and rapid identification of combat trauma patients at highest risk for massive transfusion. These powerful approaches may uncover novel correlations and help improve triage, activation of massive transfusion resources, and trauma-related outcomes. Further research seeking to optimize and apply these algorithms to trauma-centered research should be pursued.

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.

Optimal Prospective Predictors of Mortality in Austere Environments.

BACKGROUND: Prospective predictors of trauma-related outcomes have been validated to guide management in low-resource settings. The primary objective of this study was to determine the optimal prospective prediction method for mortality within combat and humanitarian trauma. MATERIALS AND METHODS: Retrospective review of the Department of Defense Trauma Registry from 2008 to 2016 was performed for adult patients. Areas under receiver operating characteristic curves (AUROCs) were calculated to assess the predictability of shock index (SI), reverse SI × Glasgow Coma Scale (rSIG), SI × Glasgow Coma Scale (SIG), Revised Trauma Score, and Trauma and Injury Severity Score (TRISS) on mortality at point of injury, arrival in emergency department (ED), and the difference in vital signs between those time points. RESULTS: A total of 22,218 patients were included. Overall, 97.1% were male, median age range 25-29 y, Injury Severity Score 9.4 ± 0.07, with predominantly penetrating injuries (58.1%), and mortality of 3.4%. ED vitals yielded higher predictability of mortality for all tests based on higher AUROCs. TRISS and rSIG demonstrated the highest AUROCs (0.955 and 0.923, respectively). The optimal cutoff value for rSIG was 14.1 (sensitivity 89% and specificity 87%). rSIG values <14.1 were significantly associated with mortality (P < 0.01; odds ratio = 5.901). CONCLUSIONS: Initial ED vital signs represented a better predictor of early mortality compared with point of injury vital signs for all predictive tools assessed. TRISS and rSIG proved to be most predictive of mortality. However, of the prospective tools assessed, rSIG may be optimal scoring tool because of its ease of calculation and its increased ability to predict mortality.

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.

Microdermal Implants Show No Effect on Surrounding Tissue During Surgery With Electrocautery.

BACKGROUND: Microdermal implants are an increasingly popular form of body jewelry. The potential for electrical conduction burn at the site of metal jewelry left in situ during electrosurgery has prompted surgical societies to recommend routine removal before surgery. To date, however, there is a lack of evidence to support this practice. We assessed in vivo thermal effect and tissue damage around implants during and after electrocautery. MATERIALS AND METHODS: Stainless steel microdermal anchors were surgically implanted into four swine. After allowing for initial healing, negative controls were excised and evaluated. An electrocautery grounding pad was placed 2 cm caudal to the implant. Continuous electrocautery (coagulation/30 W) for 30 s was applied to the skin 2 cm cranial to the implant. Surface skin temperature was recorded during electrocautery using thermal imaging. Tissue damage was assessed by gross examination and histologic evaluation. The same procedure was then performed to the contralateral nonimplanted side as a sham control. RESULTS: Electrocoagulation raised skin temperature around the electrocautery tip 27.7°C (Tmax 64.8°C). Skin temperature around the dermal implant rose 1.58°C (Tmax 38.6°C) compared with 2.03°C (Tmax 39.2°C) in the nonimplanted control skin (P = 0.627). Skin temperatures at implanted and control sites showed no statistical difference at any recorded time interval. Histologic review of excised tissue samples showed no evidence of thermal injury. CONCLUSIONS: Metallic implants appear to have no effect on skin temperature during the use of electrocautery even when in close proximity to both the electrocautery pen and return pad. Aggressive steps to remove microdermal implants before surgery may be unnecessary.

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.

Quantifying the benefit of whole blood on mortality in trauma patients requiring emergent laparotomy.

BACKGROUND: Whole blood (WB) transfusions in trauma represent an increasingly utilized resuscitation strategy in trauma patients. Previous reports suggest a probable mortality benefit with incorporating WB into massive transfusion protocols. However, questions surrounding optimal WB practices persist. We sought to assess the association between the proportion of WB transfused during the initial resuscitative period and its impact on early mortality outcomes for traumatically injured patients. METHODS: We performed a retrospective analysis of severely injured patients requiring emergent laparotomy and ≥ 3 units of red blood cell containing products (WB or packed red blood cells) within the first hour from an ACS Level 1 Trauma Center (2019-2022). Patients were evaluated based on the proportion of WB they received compared to packed red blood cells during their initial resuscitation (high ratio cohort ≥50% WB vs low ratio cohort <50% WB). Multilevel Bayesian regression analyses were performed to calculate the posterior probabilities and risk ratios (RR) associated with a WB predominant resuscitation for early mortality outcomes. RESULTS: 266 patients were analyzed (81% male, mean age of 36 years old, 61% penetrating injury, mean ISS of 30). The mortality was 11% at 4-hours and 14% at 24-hours. The high ratio cohort demonstrated a 99% (RR 0.12; 95% CrI 0.02-0.53) and 99% (RR 0.22; 95% CrI 0.08-0.65) probability of decreased mortality at 4-hours and 24-hours, respectively, compared the low ratio cohort. There was a 94% and 88% probability of at least a 50% mortality relative risk reduction associated with the WB predominate strategy at 4 hours and 24 hours, respectively. CONCLUSION: Preferential transfusion of WB during the initial resuscitation demonstrated a 99% probability of being superior to component predominant resuscitations with regards to 4 and 24-hour mortality suggesting that WB predominant resuscitations may be superior for improving early mortality. Prospective, randomized trials should be sought. LEVEL OF EVIDENCE: Therapeutic, Level III.

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.

Early Use of Extracorporeal Membrane Oxygenation for Traumatically Injured Patients: A National Trauma Database Analysis.

INTRODUCTION: Extracorporeal membrane oxygenation (ECMO) in acute trauma patients is a poorly characterized event. While ECMO most commonly has been deployed for advanced cardiopulmonary or respiratory failure following initial resuscitation, growing levels of evidence for out of hospital cardiac arrest support early ECMO cannulation as part of resuscitative efforts. We sought to perform a descriptive analysis evaluating traumatically injured patients, who were placed on ECMO, during their initial resuscitation period. METHODS: We performed a retrospective analysis of the Trauma Quality Improvement Program Database from 2017 to 2019. All traumatically injured patients who received ECMO within the first 24 hours of their hospitalization were assessed. Descriptive statistics were used to define patient characteristics and injury patterns associated with the need for ECMO, while mortality represented the primary outcome evaluated. RESULTS: A total of 696 trauma patients received ECMO during their hospitalization, of which 221 were placed on ECMO within the first 24 hours. Early ECMO patients were on average 32.5 years old, 86% male, and sustained a penetrating injury 9% of the time. The average ISS was 30.7, and the overall mortality rate was 41.2%. Prehospital cardiac arrest was noted in 18.2% of the patient population resulting in a 46.8% mortality. Of those who underwent resuscitative thoracotomy, a 53.3% mortality rate was present. CONCLUSION: Early cannulation for ECMO in severely injured patients may provide an opportunity for rescue therapy following severe injury patterns. Further evaluation regarding the safety profile, cannulation strategies, and optimal injury patterns for these techniques should be evaluated.

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: 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.

Risk of acute kidney injury requiring hemodialysis after contrast-enhanced imaging after traumatic injury: A National Trauma Databank analysis.

BACKGROUND: Trauma patients undergo routine contrast administration for diagnostic and therapeutic purposes. The aim of this study is to investigate the incidence and predictors of contrast-induced nephropathy requiring acute hemodialysis in the trauma population. METHODS: Adult patients (age ≥16) were identified from the National Trauma Databank (2017-2018) and were grouped based on contrast received. The defined groups included no contrast, computed tomography intravascular contrast only, and angiography contrast. Patient demographic and clinical variables collected included vital signs (systolic blood pressure, pulse rate) recorded upon arrival to the emergency room, injury severity score, shock index, Glasgow Coma Scale, and mechanism. Outcome measures included mortality, hospital discharge disposition, intensive care unit and hospital length of stay, and need for hemodialysis. We performed a Poisson regression to assess relative risk for undergoing hemodialysis during hospital admission. RESULTS: In total, 1,850,460 patients were included in the analysis (no contrast: 1,189,209; computed tomography intravascular contrast only: 621,846; angiography: 39,405); 3,135 patients required hemodialysis during the admission. Patients with reduced Glasgow Coma Scale, higher injury severity score, higher shock index, and preexisting diabetes mellitus and hypertension were more likely to require hemodialysis. Poisson regression revealed the relative risk of requiring hemodialysis as 1.49 with computed tomography intravascular contrast only, 4.33 with angiography only, and 5.35 with consecutive computed tomography intravascular and angiography. CONCLUSION: Intravascular contrast administration through computed tomography and or angiography is independently associated with increased risk of requiring hemodialysis after a traumatic injury. Trauma surgeons should consider the necessity of contrast for each clinical situation and understand the potential for contrast-induced nephropathy.

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.

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.

Utilization of Machine Learning Approaches to Predict Mortality in Pediatric Warzone Casualties.

BACKGROUND: Identification of pediatric trauma patients at the highest risk for death may promote optimization of care. This becomes increasingly important in austere settings with constrained medical capabilities. This study aimed to develop and validate predictive models using supervised machine learning (ML) techniques to identify pediatric warzone trauma patients at the highest risk for mortality. METHODS: Supervised learning approaches using logistic regression (LR), support vector machine (SVM), neural network (NN), and random forest (RF) models were generated from the Department of Defense Trauma Registry, 2008-2016. Models were tested and compared to determine the optimal algorithm for mortality. RESULTS: A total of 2,007 patients (79% male, median age range 7-12 years old, 62.5% sustaining penetrating injury) met the inclusion criteria. Severe injury (Injury Severity Score > 15) was noted in 32.4% of patients, while overall mortality was 7.13%. The RF and SVM models displayed recall values of .9507 and .9150, while LR and NN displayed values of .8912 and .8895, respectively. Random forest (RF) outperformed LR, SVM, and NN on receiver operating curve (ROC) analysis demonstrating an area under the ROC of .9752 versus .9252, .9383, and .8748, respectively. CONCLUSION: Machine learning (ML) techniques may prove useful in identifying those at the highest risk for mortality within pediatric trauma patients from combat zones. Incorporation of advanced computational algorithms should be further explored to optimize and supplement the diagnostic and therapeutic decision-making process.

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.