Frequency of deployed emergency donor panel use prior to implementation of the low titre group O whole blood program

INTRODUCTION

The US military has frequently used a 'walking blood bank', formally known as an 'emergency donor panel' (EDP) to obtain warm fresh whole blood (WFWB) which is then immediately transfused into the casualty. We describe the frequency of EDP activation by the US military.

METHODS

We analysed data from 2007 to 2015 within the Department of Defense Trauma Registry for US, Coalition and US contractor casualties that received at least 1 unit of blood product within the first 24 hours and described the frequency of WFWB use.

RESULTS

There were 3474 casualties that met inclusion, of which, 290 casualties (8%) required activation of the EDP. The highest proportion of EDP events was in 2014, whereas the highest number of EDP events was in 2011. Median injury severity scores were higher in the recipients, compared with non-EDP recipients (29 vs 20), as were proportions with serious injuries to the abdomen (43% vs 19%) and extremities (77% vs 65%). The median number of units of all blood products, except for packed red blood cells, was higher for WFWB recipients. Of the WFWB recipients, the median was 5 units (IQR 2-10) with a maximum documented 144 units. There were four documented cases of EDP recipients receiving >100 units of WFWB with only one surviving to hospital discharge. During the study period, there were a total of 3102 (3%) units of WFWB transfused among a total of 104 288 total units.

CONCLUSIONS

We found nearly 1 in 11 casualties who received blood required activation of the EDP. Blood from the EDP accounted for 3% of all units transfused. These findings will enable future mission planning and medical training, especially for units with smaller, limited blood supplies. The lessons learned here can also enable mass casualty planning in civilian settings.

Intramuscular administration of tranexamic acid in a large swine model of hemorrhage with hyperfibrinolysis

BACKGROUND

Traumatic injury with subsequent hemorrhage is one of the leading causes of mortality among military personnel and civilians alike. Posttraumatic hemorrhage accounts for 40% to 50% of deaths in severe trauma patients occurring secondary to direct vessel injury or the development of trauma-induced coagulopathy (TIC). Hyperfibrinolysis plays a major role in TIC and its presence increases a patient's risk of mortality. Early therapeutic intervention with intravenous (IV) tranexamic acid (TXA) prevents development of hyperfibrinolysis and subsequent TIC leading to decreased mortality. However, obtaining IV access in an austere environment can be challenging. In this study, we evaluated the efficacy of intramuscular (IM) versus IV TXA at preventing hyperfibrinolysis in a hemorrhaged swine.

METHODS

Yorkshire cross swine were randomized on the day of study to receive IM or IV TXA or no treatment. Swine were sedated, intubated, and determined to be hemodynamically stable before experimentation. Controlled hemorrhaged was induced by the removal of 30% total blood volume. After hemorrhage, swine were treated with 1,000 mg of IM or IV TXA. Control animals received no treatment. Thirty minutes post-TXA treatment, fibrinolysis was induced with a 50-mg bolus of tissue plasminogen activator. Blood samples were collected to evaluate blood TXA concentrations, blood gases, blood chemistry, and fibrinolysis.

RESULTS

Blood TXA concentrations were significantly different between administration routes at the early time points but were equivalent by 20 minutes after injection, remaining consistently elevated for up to 3 hours postadministration. Induction of fibrinolysis resulted in 87.18 ± 4.63% lysis in control animals, compared with swine treated with IM TXA, 1.96 ± 2.66% and 1.5 ± 0.42% lysis in the IV TXA group.

CONCLUSION

In the large swine model of hemorrhage with hyperfibrinolysis, IM TXA is bioequivalent and equally efficacious in preventing hyperfibrinolysis as IV TXA administration.

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.

A survey of low titer O whole blood use within the trauma quality improvement program registry

INTRODUCTION

The use of low titer O whole blood (LTOWB) has expanded although it remains unclear how many civilian trauma centers are using LTOWB.

METHODS

We analyzed data on civilian LTOWB recipients in the American College of Surgeons Trauma Quality Improvement Program (TQIP) database 2020-2021. Unique facility keys were used to determine the number of centers that used LTOWB in that period.

RESULTS

A total of 16,603 patients received LTOWB in the TQIP database between 2020 and 2021; 6600 in 2020, and 10,003 in 2021. The total number of facilities that reported LTOWB use went from 287/779 (37%) in 2020 to 302/795 (38%) in 2021. Between 2020 and 2021, among all level 1-3 designated trauma facilities that report to TQIP LTOWB use increased at level-1 centers (118 to 129), and level-2 centers (81 to 86), but decreased in level-3 facilities (9 to 4). Among pediatric and dual pediatric-adult designated hospitals there was a decrease in the number of pediatric level-1 centers (29 to 28) capable of administering LTOWB. Among centers with either single or dual level-1 trauma center designation with adult centers, the number that administered LTOWB to injured pediatric patients also decreased from 17 to 10, respectively.

CONCLUSIONS

There was an increase in the number of facilities transfusing LTOWB between 2020 and 2021. The use of LTOWB is underutilized in children at centers that have it available. These findings inform the expansion of LTOWB use in trauma.

Interventions associated with survival after prehospital intubation in the deployed combat setting

INTRODUCTION

Airway compromise is the second leading cause of potentially preventable death on the battlefield. Prehospital airway management is often unavoidable in a kinetic combat environment and expected to increase in future wars where timely evacuation will be unreliable and air superiority not guaranteed. We compared characteristics of survivors to non-survivors among combat casualties undergoing prehospital airway intubation.

MATERIALS AND METHODS

We requested all Department of Defense Trauma Registry (DODTR) encounters during 2007-2023 with documentation of any airway intervention or assessment within the first 72-h after injury. We conducted a retrospective cohort study of all casualties with intubation documented in the prehospital setting. We used descriptive and inferential statistical analysis to compare survivors through 7 days post injury versus non-survivors. We constructed 3 multivariable logistic regression models to test for associations between interventions and 7-day survival after adjusting for injury severity score, mechanism of injury, and receipt of sedatives, paralytics, and blood products.

RESULTS

There were 1377 of 48,301 patients with documentation of prehospital intubation in a combat setting. Of these, 1028 (75%) survived through 7 days post injury. Higher proportions of survivors received ketamine, paralytic agents, parenteral opioids, and parenteral benzodiazepines; there was no difference in the proportions of survivors versus non-survivors receiving etomidate. The multivariable models consistently demonstrated positive associations between 7-day survival and receipt of non-depolarizing paralytics and opioid analgesics.

CONCLUSIONS

We found an association between non-depolarizing paralytic and opioid receipt with 7-day survival among patients undergoing prehospital intubation. The literature would benefit from future multi-center randomized controlled trials to establish optimal pharmacologic strategies for trauma patients undergoing prehospital intubation.

A prospective, pragmatic non-inferiority study of emergency intubation success with the single-use i-view versus standard reusable video laryngoscope

INTRODUCTION

Video laryngoscope (VL) technology improves first-pass success. The novel i-view VL device is inexpensive and disposable. We sought to determine the first-pass intubation success with the i-view VL device versus the standard reusable VL systems in routine use at each site.

METHODS

We performed a prospective, pragmatic study at two major emergency departments (EDs) when VL was used. We rotated i-view versus reusable VL as the preferred device of the month based on an a priori schedule. An investigator-initiated interim analysis was performed. Our primary outcome was a first-pass success with a non-inferiority margin of 10% based on the per-protocol analysis.

RESULTS

There were 93 intubations using the reusable VL devices and 81 intubations using the i-view. Our study was stopped early due to futility in reaching our predetermined non-inferiority margin. Operator and patient characteristics were similar between the two groups. The first-pass success rate for the i-view group was 69.1% compared to 84.3% for the reusable VL group. A non-inferiority analysis indicated that the difference (-15.1%) and corresponding 90% confidence limits (-25.3% to -5.0%) did not fall within the predetermined 10% non-inferiority margin.

CONCLUSIONS

The i-view device failed to meet our predetermined non-inferiority margin when compared to the reusable VL systems with the study stopping early due to futility. Significant crossover occurred at the discretion of the intubating operator during the i-view month.

Blood consumption in the Role 2 setting: A Department of Defense Trauma Registry analysis

BACKGROUND

The Role 2 setting represents the most far-forward military treatment facility with limited surgical and holding capabilities. There are limited data to guide recommendations on blood product utilization at the Role 2. We describe the consumption of blood products in this setting.

STUDY DESIGN AND METHODS

We analyzed data from 2007 to 2023 from the Department of Defense Trauma Registry (DODTR) that received care at a Role 2. We used descriptive and inferential statistics to characterize the volumes of blood products consumed in this setting. We also performed a secondary analysis of US military, Coalition, and US contractor personnel.

RESULTS

Within our initial cohort analysis of 15,581 encounters, 17% (2636) received at least one unit of PRBCs or whole blood, of which 11% received a submassive transfusion, 4% received a massive transfusion, and 1% received a supermassive transfusion. There were 6402 encounters that met inclusion for our secondary analysis. With this group, 5% received a submassive transfusion, 2% received a massive transfusion, and 1% received a supermassive transfusion.

CONCLUSIONS

We described volumes of blood products consumed at the Role 2 during recent conflicts. The maximum number of units consumed among survivors exceeds currently recommended available blood supply. Our findings suggest that rapid resupply and cold-stored chain demands may be higher than anticipated in future conflicts.

Association of freeze-dried plasma with 24-h mortality among trauma patients at risk for hemorrhage

BACKGROUND

Blood products form the cornerstone of contemporary hemorrhage control but are limited resources. Freeze-dried plasma (FDP), which contains coagulation factors, is a promising adjunct in hemostatic resuscitation. We explore the association between FDP alone or in combination with other blood products on 24-h mortality.

STUDY DESIGN AND METHODS

This is a secondary data analysis from a cross-sectional prospective observational multicenter study of adult trauma patients in the Western Cape of South Africa. We compare mortality among trauma patients at risk of hemorrhage in three treatment groups: Blood Products only, FDP + Blood Products, and FDP only. We apply inverse probability of treatment weighting and fit a multivariable Cox proportional hazards model to assess the hazard of 24-h mortality.

RESULTS

Four hundred and forty-eight patients were included, and 55 (12.2%) died within 24 h of hospital arrival. Compared to the Blood Products only group, we found no difference in 24-h mortality for the FDP + Blood Product group (p = .40) and a lower hazard of death for the FDP only group (hazard = 0.38; 95% CI, 0.15-1.00; p = .05). However, sensitivity analyses showed no difference in 24-h mortality across treatments in subgroups with moderate and severe shock, early blood product administration, and accounting for immortal time bias.

CONCLUSION

We found insufficient evidence to conclude there is a difference in relative 24-h mortality among trauma patients at risk for hemorrhage who received FDP alone, blood products alone, or blood products with FDP. There may be an adjunctive role for FDP in hemorrhagic shock resuscitation in settings with significantly restricted access to blood products.

Early Vital Sign Thresholds Associated with 24-Hour Mortality among Trauma Patients: A Trauma Quality Improvement Program (TQIP) Study

BACKGROUND

Identifying patients at imminent risk of death is critical in the management of trauma patients. This study measures the vital sign thresholds associated with death among trauma patients.

METHODS

This study included data from patients ≥15 years of age in the American College of Surgeons Trauma Quality Improvement Program (TQIP) database. Patients with vital signs of zero were excluded. Documented prehospital and emergency department (ED) vital signs included systolic pressure, heart rate, respiratory rate, and calculated shock index (SI). The area under the receiver operator curves (AUROC) was used to assess the accuracy of these variables for predicting 24-hour survival. Optimal thresholds to predict mortality were identified using Youden's Index, 90% specificity, and 90% sensitivity. Additional analyses examined patients 70+ years of age.

RESULTS

There were 1,439,221 subjects in the 2019-2020 datasets that met inclusion for this analysis with <0.1% (10,270) who died within 24 hours. The optimal threshold for prehospital systolic pressure was 110, pulse rate was 110, SI was 0.9, and respiratory rate was 15. The optimal threshold for the ED systolic was 112, pulse rate was 107, SI was 0.9, and respiratory rate was 21. Among the elderly sub-analysis, the optimal threshold for prehospital systolic was 116, pulse rate was 100, SI was 0.8, and respiratory rate was 21. The optimal threshold for ED systolic was 121, pulse rate was 95, SI was 0.8, and respiratory rate was 0.8.

CONCLUSIONS

Systolic blood pressure (SBP) and SI offered the best predictor of mortality among trauma patients. The SBP values predictive of mortality were significantly higher than the traditional 90mmHg threshold. This dataset highlights the need for better methods to guide resuscitation as initial vital signs have limited accuracy in predicting subsequent mortality.

Effectiveness of Mobile Applications for Trauma Care in Combat Casualty Simulations Throughout the Continuum

INTRODUCTION

The U.S. Military uses handwritten documentation throughout the continuum of combat casualty care to document from point-of-injury, during transport and at facilities that provide damage control resuscitation and surgery. Proven impractical due to lack of durability and legibility in arduous tactical environments, we hypothesized that mobile applications would increase accuracy and completeness of documentation in combat casualty simulations.

METHODS

We conducted simulations across this continuum utilizing 10 two-person teams consisting of a Medic and an Emergency or Critical Care Nurse. Participants were randomized to either the paper group or BATDOK and T6 Health Systems mobile application group. Simulations were completed in both the classroom and simulated field environments. All documentation was assessed for speed, completeness, and accuracy.

RESULTS

Participant demographics averaged 10.8 ± 5.2 y of military service and 3.9 ± 0.6 h of training on both platforms. Classroom testing showed a significant increase in completeness (84.2 ± 8.1% versus 77.2 ± 6.9%; P = 0.02) and accuracy (77.6 ± 8.1% versus 68.9 ± 7.5%; P = 0.01) for mobile applications versus paper with no significant difference in overall time to completion (P = 0.19). Field testing again showed a significant increase in completeness (91.6 ± 5.8 % versus 70.0 ± 14.1%; P < 0.01) and accuracy (87.7 ± 7.6% versus 64.1 ± 14.4%; P < 0.01) with no significant difference in overall time to completion (P = 0.44).

CONCLUSIONS

In deployed environments, mobile applications have the potential to improve casualty care documentation completeness and accuracy with minimal additional training. These efforts will assist in meeting an urgent operational need to enable our providers.

Associations with Prehospital Antibiotic Receipt among Combat Casualties with Open Wounds: A Department of Defense Trauma Registry Study

INTRODUCTION

Current Tactical Combat Casualty Care (TCCC) guidelines recommend antibiotic administration for all open wounds to prevent infection. We identified associations between demographics, procedures, and medicines with the receipt of prehospital antibiotics among combat casualties.

MATERIALS AND METHODS

We used a series of emergency department procedure codes to identify adult subjects within the Department of Defense Trauma Registry from January 2007 to August 2016 who sustained open wounds. We compared demographics, procedures, and medicines administered among casualties receiving prehospital wound prophylaxis versus casualties not receiving antibiotic prophylaxis. We controlled for confounders with multivariable logistical regression.

RESULTS

We identified 18,366 encounters meeting inclusion criteria. Antibiotic recipients (n = 2384) were comparable to nonrecipients (n = 15,982) with regard to age and sex. Antibiotic recipients were more likely to sustain injuries from firearms and undergo all procedures examined related to hemorrhage control, airway management, pneumothorax treatment, and volume replacement except for intraosseous access. Antibiotic recipients were less likely to sustain injuries from explosives. Antibiotic recipients had a modestly higher survival than nonrecipients (97.4% versus 96.0%). Associations with prehospital antibiotic receipt in multivariable logistic regression included non-North Atlantic Treaty Organization military force affiliation (odds ratio (OR) 4.65, 95% CI, 1.0-20.8), tachycardia (OR 3.4, 95% CI, 1.1-10.5), intubation (OR 2.0, 95% CI, 1.1-3.8), and administration of tranexamic acid (OR 5.6, 95% CI, 1.2-26.5).

CONCLUSIONS

The proportion of combat casualties with open wounds receiving prehospital antibiotics was low despite published recommendations for early antibiotics in patients with open wounds. These findings highlight the ongoing need for additional educational and quality assurance initiatives to continue improving adherence to TCCC guidelines with regard to prehospital antibiotic administration. Future studies are necessary to determine reasons for suboptimal TCCC guideline compliance.

Comparative Analysis of Whole Blood Infusion Effects: Assessing LifeFlow Versus Pressure Bag in a Sus scrofa Model

BACKGROUND

To improve survival for hemorrhagic shock treatment, guidelines emphasize two patient care priorities: (1) immediate hemorrhage control and (2) early resuscitation with whole blood or blood products. The LifeFlow device is designed to rapidly infuse blood products. However, the effects of using this device compared to pressure-bag systems remain unclear. We hypothesize that there will be no laboratory-measured difference with the blood when infused through the LifeFlow versus the current standard pressure bag system.

METHODS

Two units of fresh whole blood were obtained from a sus scrofa model. One unit was "infused" using the LifeFlow with the other unit used as a control through a standard pressure bag system into an empty bag. The "before" measurements were obtained from blood samples from a standard fresh whole blood collection bag. The blood was "infused" into a whole blood bag devoid of storage solution from which the "after" measurements were obtained.

RESULTS

This study utilized 22 clinically healthy sus scrofa. Blood units were primarily obtained from a left subclavian central line (50.0%). The median time to acquire and administer a unit of blood was similar for both the LifeFlow device (8.4 min and 8.1 min) and the pressure bag (8.7 min and 7.4 min). No significant differences were found in the total time to acquire or administer blood between the two devices. The median volume of blood acquired was 500 mL for both groups. While no significant differences in blood parameters were observed between the two devices, significant differences were noted when comparing pre- and post-transfusion values within each device. For the LifeFlow device, an increase in hemoglobin and chloride levels and a decrease in thromboplastin time and glucose levels were observed. With the pressure bag, only a decrease in blood urea nitrogen was observed.

CONCLUSIONS

In comparing the LifeFlow to the pressure bag, there were no significant differences noted in the total time to acquire or administer a whole unit of blood. However, there were differences with several laboratory parameters of unclear clinical significance.

An Assessment of Clinical Accuracy of Vital Sign-based Triage Tools Among U.S. and Coalition Forces

INTRODUCTION

Early appropriate allocation of resources for critically injured combat casualties is essential. This is especially important when inundated with an overwhelming number of casualties where limited resources must be efficiently allocated, such as during mass casualty events. There are multiple scoring systems utilized in the prehospital combat setting, including the shock index (SI), modified shock index (MSI), simple triage and rapid treatment (START), revised trauma score (RTS), new trauma score (NTS), Glasgow Coma Scale + age + pressure (GAP), and the mechanism + GAP (MGAP) score. The optimal score for application to the combat trauma population remains unclear.

MATERIALS AND METHODS

This is a secondary analysis of a previously described dataset from the Department of Defense Trauma Registry from January 1, 2007 through March 17, 2020. We constructed univariable analyses to determine the area under the receiving operator characteristic (AUROC) for the scoring systems of interest. Our primary outcomes were early death (within 24 hours) or early massive transfusion, as defined by ≥3 units.

RESULTS

There were 12,268 casualties that met inclusion criteria. There were 168 (1%) who died within the first 24 hours and 2082 (17%) that underwent significant transfusion within the first 24 hours. When assessing the predictive capabilities for death within 24 hours, the AUROCs were 0.72 (SI), 0.69 (MSI), 0.89 (START), 0.90 (RTS), 0.83 (NTS), 0.90 (GAP), and 0.91 (MGAP). The AUROCs for massive transfusion were 0.89 (SI), 0.89 (MSI), 0.82 (START), 0.81 (RTS), 0.83 (NTS), 0.85 (MGAP), and 0.86 (GAP).

CONCLUSIONS

This study retrospectively applied seven triage tools to a database of 12,268 cases from the Department of Defense Trauma Registry to evaluate their performance in predicting early death or massive transfusion in combat. All scoring systems performed well with an AUROC >0.8 for both outcomes. Although the SI and MSI performed best for predicting massive transfusion (both had an AUROC of 0.89), they ranked last for assessment of mortality within 24 hours, with the other tools performing well. START, RTS, NTS, MGAP and GAP reliably identified early death and need for massive transfusion, with MGAP and GAP performing the best overall. These findings highlight the importance of assessing triage tools to best manage resources and ultimately preserve lives of traumatically wounded warfighters. Further studies are needed to explain the surprising performance discrepancy of the SI and MSI in predicting early death and massive transfusion.

A Market Assessment of Introducer Technology to Aid With Endotracheal Intubation

INTRODUCTION

Endotracheal intubation is a potentially lifesaving procedure. Previously, data demonstrated that intubation remains the most performed airway intervention in the Role 1 setting. Additionally, deployed data demonstrate that casualties intubated in the prehospital setting have worse survival than those intubated in the emergency department setting. Technological solutions may improve intubation success in this setting. Certain intubation practices, including the use of endotracheal tube introducer bougies, facilitate intubation success especially in patients with difficult airways. We sought to determine the current state of the market for introducer devices.

MATERIALS AND METHODS

This market review utilized Google searches to find products for intubation. The search criteria aimed to identify any device ideal for intubation in the emergency setting. Device data retrieved included manufacturer, device, cost, and design descriptions.

RESULTS

We identified 12 introducer-variants on the market. Devices varied with regards to composition (latex, silicone, polyethylene, combination of several materials, etc.), tip shape, special features for ease of intubation (markings for depth and visibility, size, etc.), disposability/reuse capability, measurements, and prices. The cost of each device ranged from approximately $5 to $100.

CONCLUSIONS

We identified 12 introducer-variants on the market. Clinical studies are necessary to determine which devices may improve patient outcomes in the Role 1 setting.

A Review of Electrolyte, Mineral, and Vitamin Changes After Traumatic Brain Injury

INTRODUCTION

Despite the prevalence of traumatic brain injury (TBI) in both civilian and military populations, the management guidelines developed by the Joint Trauma System involve minimal recommendations for electrolyte physiology optimization during the acute phase of TBI recovery. This narrative review aims to assess the current state of the science for electrolyte and mineral derangements found after TBI.

MATERIALS AND METHODS

We used Google Scholar and PubMed to identify literature on electrolyte derangements caused by TBI and supplements that may mitigate secondary injuries after TBI between 1991 and 2022.

RESULTS

We screened 94 sources, of which 26 met all inclusion criteria. Most were retrospective studies (n = 9), followed by clinical trials (n = 7), observational studies (n = 7), and case reports (n = 2). Of those, 29% covered the use of some type of supplement to support recovery after TBI, 28% covered electrolyte or mineral derangements after TBI, 16% covered the mechanisms of secondary injury after TBI and how they are related to mineral and electrolyte derangements, 14% covered current management of TBI, and 13% covered the potential toxic effects of the supplements during TBI recovery.

CONCLUSIONS

Knowledge of mechanisms and subsequent derangements of electrolyte, mineral, and vitamin physiology after TBI remains incomplete. Sodium and potassium tended to be the most well-studied derangements after TBI. Overall, data involving human subjects were limited and mostly involved observational studies. The data on vitamin and mineral effects were limited, and targeted research is needed before further recommendations can be made. Data on electrolyte derangements were stronger, but interventional studies are needed to assess causation.

Seasonal Association With Hypothermia in Combat Trauma

INTRODUCTION

Hypothermia increases mortality in trauma populations and frequently occurs in military casualties due to the nature of combat environments. The association between hypothermia and the time of year when injured remains unclear. We sought to determine the association between seasonal changes in temperature and hypothermia among combat casualties.

MATERIALS AND METHODS

This observational study was a secondary analysis of a previously described Department of Defense Trauma Registry dataset which included U.S. military and Coalition casualties who received prehospital care from January 2007 to March 2020 in Afghanistan and Iraq. We tested for associations between hypothermia (<36.2°C) and seasonal ambient temperatures by constructing multivariable logistic regression models. Summer was defined as June through August and winter as December through February. We assumed that the combat operations occurred in the area near the point of first contact with the deployed military treatment facilities. This study was determined to be exempt from Institutional Review Board oversight.

RESULTS

There were 5,821 that met inclusion for this study. Within the multivariable logistic regression model, we adjusted for injury severity score, mechanism of injury, and imputed transport time, finding that combat casualties were 2.28 (odds ratio, 95% confidence interval 1.93-2.69) times more likely to develop hypothermia in the winter versus summer. When using temperature as a continuous outcome, casualties had a lower emergency department temperature during the winter (parameter estimate -0.133°C, P < 0.001) after adjusting for confounders. In casualties experiencing hypothermia, mortality was higher (4% versus 1%, P < 0.001), and composite median injury severity score values were higher (10 versus 5, P < 0.001). Among hypothermic casualties, serious injuries were significantly more common (all P < 0.001) to the head (15% versus 7%), thorax (15% versus 7%), abdomen (9% versus 6%), extremities (35% versus 22%), and skin (4% versus 2%).

CONCLUSIONS

We found a seasonal variation in the occurrence of hypothermia in a large cohort of trauma casualties. Despite adjustment for multiple known confounders, our findings substantiate probable ambient temperature variations to trauma-induced hypothermia. Furthermore, our findings, when taken in the context of other studies on the efficacy of current hypothermia prevention and treatment strategies, support the need for better methods to mitigate hypothermia in future cold-weather operations.

A Narrative Review of Existing and Developing Biomarkers in Acute Traumatic Brain Injury for Potential Military Deployed Use

INTRODUCTION

Traumatic brain injury (TBI) is a leading cause of morbidity and mortality in both adult civilian and military populations. Currently, diagnostic and prognostic methods are limited to imaging and clinical findings. Biomarker measurements offer a potential method to assess head injuries and help predict outcomes, which has a potential benefit to the military, particularly in the deployed setting where imaging modalities are limited. We determine how biomarkers such as ubiquitin C-terminal hydrolase-L1 (UCH-L1), glial fibrillary acidic protein (GFAP), S100B, neurofilament light chain (NFL), and tau proteins can offer important information to guide the diagnosis, acute management, and prognosis of TBI, specifically in military personnel.

MATERIALS AND METHODS

We performed a narrative review of peer-reviewed literature using online databases of Google Scholar and PubMed. We included articles published between 1988 and 2022.

RESULTS

We screened a total of 73 sources finding a total of 39 original research studies that met inclusion for this review. We found five studies that focused on GFAP, four studies that focused on UCH-L1, eight studies that focused on tau proteins, six studies that focused on NFL, and eight studies that focused on S100B. The remainder of the studies included more than one of the biomarkers of interest.

CONCLUSIONS

TBI occurs frequently in the military and civilian settings with limited methods to diagnose and prognosticate outcomes. We highlighted several promising biomarkers for these purposes including S100B, UCH-L1, NFL, GFAP, and tau proteins. S100B and UCH-L1 appear to have the strongest data to date, but further research is necessary. The robust data that explain the optimal timing and, more importantly, trending of these biomarker measurements are necessary before widespread application.

Association of Prehospital Neck Wound Survivability and Battlefield Medical Evacuation Time in Afghanistan

INTRODUCTION

The U.S. Military's Golden Hour policy led to improved warfighter survivability during the Global War on Terror. The policy's success is well-documented, but a categorical evaluation and stratification of medical evacuation (MEDEVAC) times based on combat injury is lacking.

METHODS

We queried the Department of Defense Joint Trauma System Prehospital Trauma Registry for casualties with documented penetrating neck trauma in Afghanistan requiring battlefield MEDEVAC from June 15, 2009, through February 1, 2021. Casualties were excluded if the time from the point of injury to reach higher level medical care was not documented, listed as zero, or exceeded 4 hours. They were also excluded if demographic data were incomplete or deemed unreliable or if their injuries occurred outside of Afghanistan.We designed a logistic regression model to test for associations in survivability, adjusting for composite injury severity score, patient age group, and type of next higher level of care reached. We then used our model to interpolate MEDEVAC times associated with 0.1%, 1%, and 10% increased risk of death for an incapacitated casualty with penetrating neck trauma.

RESULTS

Of 1,147 encounters, 444 casualties met inclusion criteria. Of these casualties, 430 (96.9%) survived to discharge. Interpolative analysis of our multivariable logistic regression model showed that MEDEVAC times ≥8 minutes, ≥53 minutes, and ≥196 minutes are associated with a 0.1%, 1%, and 10% increased risk of mortality from baseline, respectively.

CONCLUSIONS

Our data characterize the maximum MEDEVAC times associated with 0.1%, 1%, and 10% increased risk of death from baseline survivability for penetrating battlefield neck trauma in Afghanistan.

Management of Combat Casualties during Aeromedical Evacuation from a Role 2 to a Role 3 Medical Facility

INTRODUCTION

Emergent clinical care and patient movements through the military evacuation system improves survival. Patient management differs when transporting from the point-of-injury (POI) to the first medical treatment facility (MTF) versus transporting from the Role 2 to the Role 3 MTF secondary to care rendered within the MTF, including surgery and advanced resuscitation. The objective of this study was to describe care provided to patients during theater inter-facility transports and compare with pre-hospital transports (POI to first MTF).

MATERIALS AND METHODS

We performed a retrospective chart review of patients with the Role 2 to the Role 3 transports in Afghanistan and Iraq from 2007 to 2016. Data collected included procedures and events at the MTF and during transport. We compared the intra-theater transport data (Role 2 to Role 3) to data from a previous study evaluating pre-hospiital transports (POI to first MTF).

RESULTS

We reviewed the records of 869 Role 2 to Role 3 transport patients. Role 2 to Role 3 transports were longer in duration compared to POI transports (39 minutes vs. 23 minutes) and were more likely to be staffed by advanced personnel (nurses, physician assistants, and physicians) (57% vs. 3%). The sample primarily consisted of military-aged males (mean age 27 years) who suffered from explosive or blunt force injuries. Procedures performed during each phase of care reflected the capabilities of the teams and locations. Pain and cardiac events were more common in POI evacuations compared to the Role 2 to Role 3 transports, but documentation of respiratory events, hemodynamic events, neurologic events, and equipment failure was more common during the Role 2 to Role 3 transports. Survival rates were slightly higher among the Role 2 to Role 3 cohort (98% vs. 95%, difference 3% [95% confidence interval of the difference 1-5%]).

CONCLUSIONS

Inter-facility transports (Role 2 to Role 3) are longer in duration, transport more complex patients, and are staffed by more advanced level provider types compared to transports from POI.

Market Analysis of Video Laryngoscopy Equipment for the Role 1 Setting

INTRODUCTION

Airway compromise is the second leading cause of potentially preventable prehospital combat death. Endotracheal intubation (ETI) remains the most common role 1 airway intervention. Video laryngoscopy (VL) is superior to direct laryngoscopy (DL) for first-attempt intubation, especially in less-experienced providers and for trauma patients. The cost has been a major challenge in pushing VL technology far-forward; however, the cost of equipment continues to become more affordable. We conducted a market analysis of VL devices under $10,000 for possible options for role 1.

MATERIALS AND METHODS

We searched Google, PubMed, and the Food and Drug Administration database from August 2022 to January 2023 with a combination of several keywords to identify current VL market options under $10,000. After identifying relevant manufacturers, we then reviewed individual manufacturer or distributor websites for pricing data and system specifications. We noted several characteristics regarding VL device design for comparison. These include monitor features, size, modularity, system durability, battery life, and reusability. When necessary, we requested formal price quotes from respective companies.

RESULTS

We identified 17 VL options under $10,000 available for purchase, 14 of which were priced below $5,000 for individual units. Infium (n = 3) and Vimed Medical (n = 4) provided the largest number of unique models. VL options under $10,000 exist in both reusable and disposable modalities. These modalities included separate monitors as well as monitors attached to the VL handle. Disposable options, on a per-unit basis, cost less than reusable options.

CONCLUSIONS

Several VL options exist within our goal price point in both reusable and disposable options. Clinical studies assessing the technology performance of ETI and deliberate downselection are needed to identify the most cost-effective solution for role 1 dispersion.

A Pilot Medic-based Assessment of the Novel Handheld LifeFlow Device for Rapid Infusion of Blood Products

INTRODUCTION

Uncontrolled hemorrhage remains the leading cause of preventable death in the prehospital, combat setting. Treatment guidelines emphasize immediate hemorrhage control and early resuscitation with whole blood or blood products. Current methods for the delivery of blood products are often insufficient to provide trauma resuscitation. The novel LifeFlow device is a hand-powered device that can rapidly infuse fluids, including blood products. However, successful use of this device in the hands of the intended end user has not been demonstrated.

MATERIALS AND METHODS

We conducted a pilot study to assess how quickly and effectively medics could set up the LifeFlow device and infuse mock blood products into a casualty. They were provided with a brief block of instruction (<10 min) and the opportunity to handle the device. The time to set up the device and proportion of successful completion were recorded. Participants were surveyed regarding the use of the device including post-study interview.

RESULTS

Forty medics, who were recruited and eligible to participate, completed the study procedures. All medics were able to successfully set up the device and perform the infusion. We had two instances of fluid leakage owing to malfunctions with the simulation arm, not the LifeFlow device. The mean time to device setup was 112 s (95% confidence interval [CI], 101-124). The mean time for infusion of 500 mL of fluid was 94 s (95% CI, 83-105). The mean time for all procedures was 197 s (95% CI, 178-213). On product feedback, they generally found it easier to use, easy to manipulate, possessing a useful grip, easily set up, and requiring minimal training.

CONCLUSIONS

The medics were able to reliably assemble and use the LifeFlow rapid infusion device. However, there were concerns about the packaging and the single indication for the device.

Ketamine during resuscitation - Is it as hemodynamically perfect as we think?

INTRODUCTION

Ketamine administration in patients experiencing or at risk for hypotension is common based upon the presumption of this agent's favorable hemodynamic profile. The Compensatory Reserve Measurement (CRM) is a novel algorithm that accurately tracks systemic adequacy for delivery of oxygen (DO2) to the tissues. We present a case series of trauma patients receiving ketamine with CRM measurements to offer insight into the DO2 during resuscitation.

METHODS

We captured vital signs along with analog arterial waveform data from trauma patients meeting major activation criteria using a prospective study design. Study team members tracked interventions and vital signs including systolic blood pressure (SBP), mean arterial pressure (MAP), and heart rate (HR) throughout their emergency department stay.

RESULTS

Our study included 8 patients who received ketamine for intubation or analgesia (20-300 mg) and had adequate data for analysis. Most were male (88%) with a median age of 28. The most common mechanisms of injury were motor vehicle collisions (MVCs) (38%) and gunshot wounds (38%). After ketamine administration SBP, MAP, and HR all increased while the CRM exhibited minimal change.

CONCLUSIONS

SBP, MAP, and HR generally appeared to increase while the CRM remained unchanged. Our findings suggest that while standard vital sign measurements appear to increase, ketamine may not improve delivery of oxygen to the tissues. This warrants further study to better understand the effects of ketamine on hemodynamics.

Extraglottic device use is rare during emergency airway management: A National Emergency Airway Registry (NEAR) study

INTRODUCTION

Airway management is a critical component of the management of emergency department (ED) patients. The ED airway literature primarily focuses upon endotracheal intubation; relatively less is known about the ED use of extraglottic devices (EGDs). The goal of this study was to describe the frequency of use, success, and complications for EGDs among ED patients.

METHODS

The National Emergency Airway Registry (NEAR) is a prospective, multi-center, observational registry. It captures data on all ED patients at participating sites requiring airway management. Intubating clinicians entered all data into an online system as soon as practical after each encounter. We conducted a secondary analysis of these data for all ED encounters in which EGD placement occurred. We used descriptive statistics to characterize these encounters.

RESULTS

Of 19,071 patients undergoing intubation attempts, 56 (0.3%) underwent EGD placement. Of 25 participating sites, 13 reported no cases undergoing EGD placement; the median number of EGDs placed per site was 2 (interquartile range 1-2.5, range 1-31). Twenty-nine (54%) patients had either hypotension or hypoxia prior to the start of airway management. Clinicians reported anticipation of a difficult airway in 55% and at least one difficult airway characteristic in 93% of these patients. Forty-one encounters entailed placement of a laryngeal mask airway (LMA®) Fastrach™, 33 of whom underwent subsequent successful intubation through the EGD and 7 of whom underwent intubation by alternative methods. An additional 10 encounters utilized a standard LMA® device. Providers placed 34 (61%) EGDs during the first intubation attempt. Seventeen EGD patients (30%) experienced peri-procedure adverse events, including 14 (25%) experiencing hypoxemia. None of these patients expired due to failed airways.

CONCLUSIONS

EGD use was rare in this multi-center ED registry. EGD occurred predominantly in patients with difficult airway characteristics with favorable airway management outcomes. Clinicians should consider this emergency airway device for patients with a suspected difficult airway.

Video versus Direct Laryngoscopy for Tracheal Intubation of Critically Ill Adults

BACKGROUND

Whether video laryngoscopy as compared with direct laryngoscopy increases the likelihood of successful tracheal intubation on the first attempt among critically ill adults is uncertain.

METHODS

In a multicenter, randomized trial conducted at 17 emergency departments and intensive care units (ICUs), we randomly assigned critically ill adults undergoing tracheal intubation to the video-laryngoscope group or the direct-laryngoscope group. The primary outcome was successful intubation on the first attempt. The secondary outcome was the occurrence of severe complications during intubation; severe complications were defined as severe hypoxemia, severe hypotension, new or increased vasopressor use, cardiac arrest, or death.

RESULTS

The trial was stopped for efficacy at the time of the single preplanned interim analysis. Among 1417 patients who were included in the final analysis (91.5% of whom underwent intubation that was performed by an emergency medicine resident or a critical care fellow), successful intubation on the first attempt occurred in 600 of the 705 patients (85.1%) in the video-laryngoscope group and in 504 of the 712 patients (70.8%) in the direct-laryngoscope group (absolute risk difference, 14.3 percentage points; 95% confidence interval [CI], 9.9 to 18.7; P<0.001). A total of 151 patients (21.4%) in the video-laryngoscope group and 149 patients (20.9%) in the direct-laryngoscope group had a severe complication during intubation (absolute risk difference, 0.5 percentage points; 95% CI, -3.9 to 4.9). Safety outcomes, including esophageal intubation, injury to the teeth, and aspiration, were similar in the two groups.

CONCLUSIONS

Among critically ill adults undergoing tracheal intubation in an emergency department or ICU, the use of a video laryngoscope resulted in a higher incidence of successful intubation on the first attempt than the use of a direct laryngoscope. (Funded by the U.S. Department of Defense; DEVICE ClinicalTrials.gov number, NCT05239195.).

High risk and low prevalence diseases: Blast injuries

INTRODUCTION

Blast injury is a unique condition that carries a high rate of morbidity and mortality, often with mixed penetrating and blunt injuries.

OBJECTIVE

This review highlights the pearls and pitfalls of blast injuries, including presentation, diagnosis, and management in the emergency department (ED) based on current evidence.

DISCUSSION

Explosions may impact multiple organ systems through several mechanisms. Patients with suspected blast injury and multisystem trauma require a systematic evaluation and resuscitation, as well as investigation for injuries specific to blast injuries. Blast injuries most commonly affect air-filled organs but can also result in severe cardiac and brain injury. Understanding blast injury patterns and presentations is essential to avoid misdiagnosis and balance treatment of competing interests of patients with polytrauma. Management of blast victims can also be further complicated by burns, crush injury, resource limitation, and wound infection. Given the significant morbidity and mortality associated with blast injury, identification of various injury patterns and appropriate management are essential.

CONCLUSIONS

An understanding of blast injuries can assist emergency clinicians in diagnosing and managing this potentially deadly disease.

The impact of prehospital whole blood on hemorrhaging trauma patients: A multi-center retrospective study

BACKGROUND

Whole blood (WB) use has become increasingly common in trauma centers across the United States for both in-hospital and prehospital resuscitation. We hypothesize that prehospital WB (pWB) use in trauma patients with suspected hemorrhage will result in improved hemodynamic status and reduced in-hospital blood product requirements.

METHODS

The institutional trauma registries of two academic level I trauma centers were queried for all patients from 2015-2019 who underwent transfusion upon arrival to the trauma bay. Patients who were dead on arrival or had isolated head injuries were excluded. Demographics, injury and shock characteristics, transfusion requirements, including massive transfusion protocol (MTP) (>10 U in 24 hours) and rapid transfusion (CAT3+) and outcomes were compared between pWB and non-pWB patients. Significantly different demographic, injury characteristics and pWB were included in univariate followed by stepwise logistic regression analysis to determine the relationship with shock index (SI). Our primary objective was to determine the relationship between pWB and improved hemodynamics or reduction in blood product utilization.

RESULTS

A total of 171 pWB and 1391 non-pWB patients met inclusion criteria. Prehospital WB patients had a lower median Injury Severity Score (17 vs. 21, p < 0.001) but higher prehospital SI showing greater physiologic disarray. Prehospital WB was associated with improvement in SI (-0.04 vs. 0.05, p = 0.002). Mortality and (LOS) were similar. Prehospital WB patients received fewer packed red blood cells, fresh frozen plasma, and platelets units across their LOS but total units and volumes were similar. Prehospital WB patients had fewer MTPs (22.6% vs. 32.4%, p = 0.01) despite a similar requirement of CAT3+ transfusion upon arrival.

CONCLUSION

Prehospital WB administration is associated with a greater improvement in SI and a reduction in MTP. This study is limited by its lack of power to detect a mortality difference. Prospective randomized controlled trials will be required to determine the true impact of pWB on trauma patients.

LEVEL OF EVIDENCE

Prognostic and Epidemiological; Level IV.

Military Standard Testing of Commercially Available Supraglottic Airway Devices for Use in a Military Combat Setting

INTRODUCTION

Airway obstruction is the second leading cause of death on the battlefield. The harsh conditions of the military combat setting require that devices be able to withstand extreme circumstances. Military standards (MIL-STD) testing is necessary before devices are fielded. We sought to determine the ability of supraglottic airway (SGA) devices to withstand MIL-STD testing.

METHODS

We tested 10 SGA models according to nine MIL-STD-810H test methods. We selected these tests by polling five military and civilian emergency-medicine subject matter experts (SMEs), who weighed the relevance of each test. We performed tests on three devices for each model, with operational and visual examinations, to assign a score (1 to 10) for each device after each test. We calculated the final score of each SGA model by averaging the score of each device and multiplying that by the weight for each test, for a possible final score of 2.6 to 26.3.

RESULTS

The scores for the SGA models were LMA Classic Airway, 25.9; AuraGain Disposable Laryngeal Mask, 25.5; i-gel Supraglottic Airway, 25.2; Solus Laryngeal Mask Airway, 24.4; LMA Fastrach Airway, 24.4; AuraStraight Disposable Laryngeal Mask, 24.1; King LTS-D Disposable Laryngeal Tube, 22.1; LMA Supreme Airway, 21.0; air-Q Disposable Intubating Laryngeal Airway, 20.1; and Baska Mask Supraglottic Airway, 18.1. The limited (one to three) samples available for testing provide adequate preliminary information but restrict the range of failures that could be discovered.

CONCLUSIONS

Lower scoring SGA models may not be optimal for military field use. Models scoring sufficiently close to the top performers (LMA Classic, AuraGain, i-gel, Solus, LMA Fastrach, AuraStraight) may be viable for use in the military setting. The findings of our testing should help guide device procurement appropriate for different battlefield conditions.

Prehospital and Emergency Management

Burn care in the prehospital and emergency settings requires rapid assessment of airway, breathing, and circulation. Intubation (if indicated) and fluid resuscitation are most important in emergency burn care. Total body surface area burned and depth of burn are important early assessments that help guide resuscitation and disposition. Burn care in the emergency department further includes carbon monoxide and cyanide toxicity evaluation and management.

A scoping review of two decades of pediatric humanitarian care during wartime

ABSTRACT

Humanitarian care is a vital component of the wartime mission. Children comprise a significant proportion of casualties injured by explosives and penetrating weapons. Children face a variety of unique injury patterns in the combat setting as high-powered firearms and explosives are rarely seen in the civilian setting. We sought to perform a scoping review of pediatric research from the recent US-led wars in Afghanistan, and Iraq conflicts beginning in 2001. We used Google Scholar and PubMed to identify pediatric combat literature published between 2001 and 2022. We utilized the PRISMA-ScR Checklist to conduct this review. We identified 52 studies that met inclusion for this analysis - 1 prospective observational study, 50 retrospective studies, and 1 case report. All the original research studies were retrospective in nature except for one. We identified one prospective study that was a post-hoc subanalysis from an overall study assessing the success of prehospital lifesaving interventions. Most of the papers came from varying registries created by the United States and British militaries for the purposes of trauma performance improvement. The deployed health service support mission often includes treatment of pediatric trauma patients. The deployed health service support mission often includes treatment of pediatric trauma patients. We found that available literature from this setting is limited to retrospective studies except for one prospective study. Our findings suggest that pediatric humanitarian care was a significant source of medical resource consumption within both of the major wars. Further, many of the lessons learned have directly translated into changes in civilian pediatric trauma care practices highlighting the need for collaborative scientific developments between the military and civilian trauma programs.

Improving prehospital traumatic shock care: implementation and clinical effectiveness of a pragmatic, quasi-experimental trial in a resource-constrained South African setting

OBJECTIVES

This project seeks to improve providers' practices and patient outcomes from prehospital (ie, ambulance-based) trauma care in a middle-income country using a novel implementation strategy to introduce a bundled clinical intervention.

DESIGN

We conduct a two-arm, controlled, mixed-methods, hybrid type II study.

SETTING

This study was conducted in the Western Cape Government Emergency Medical Services (EMS) system of South Africa.

INTERVENTIONS

We pragmatically implemented a simplified prehospital bundle of trauma care (with five core elements) using a novel workplace-based, peer-to-peer, rapid training format. We assigned the intervention and control sites.

OUTCOME MEASURES

We assessed implementation effectiveness among EMS providers and stakeholders, using the RE-AIM framework. Clinical effectiveness was assessed at the patient level, using changes in Shock Index x Age (SIxAge). Indices and cut-offs were established a priori. We performed a difference-in-differences (D-I-D) analysis with a multivariable mixed effects model.

RESULTS

198 of 240 (82.5%) EMS providers participated, 93 (47%) intervention and 105 (53%) control, with similar baseline characteristics. The overall implementation effectiveness was excellent (80.6%): reach was good (65%), effectiveness was excellent (87%), implementation fidelity was good (72%) and adoption was excellent (87%). Participants and stakeholders generally reported very high satisfaction with the implementation strategy citing that it was a strong operational fit and effective educational model for their organisation. A total of 770 patients were included: 329 (42.7%) interventions and 441 (57.3%) controls, with no baseline differences. Intervention arm patients had more improved SIxAge compared with control at 4 months, which was not statistically significant (-1.4 D-I-D; p=0.35). There was no significant difference in change of SIxAge over time between the groups for any of the other time intervals (p=0.99).

CONCLUSIONS

In this quasi-experimental trial of bundled care using the novel workplace rapid training approach, we found overall excellent implementation effectiveness but no overall statistically significant clinical effectiveness.

Descriptive Analysis of Combat-Associated Aspiration Pneumonia

BACKGROUND

Airway obstruction is the second leading cause of potentially preventable death on the battlefield. The treatment for airway obstruction is intubation or advanced airway adjunct, which has a known risk of aspiration. We sought to describe the variables associated with aspiration pneumonia after prehospital airway intervention.

METHODS

This is a sub-analysis of previously described data from the Department of Defense Trauma Registry (DoDTR) from 2007 to 2020. We included casualties that had at least one prehospital airway intervention with documentation of subsequent aspiration pneumonia or pneumonia within three days of the intervention. We used a generalized linear model with Firth bias estimates to test for associations.

RESULTS

There were 1,509 casualties that underwent prehospital airway device placement. Of these, 41 (2.7%) met inclusion criteria into the aspiration pneumonia cohort. The demographics had no statistical difference between the groups. The non-aspiration cohort had fewer median ventilator days (2 versus 6, p < 0.001), intensive care unit days (2 versus 7, p < 0.001, and hospital days [3 versus 8, p < 0.001]). Survival was lower in the non-aspiration cohort (74.2% versus 90.2%, p = 0.017). The administration of succinylcholine was higher in the non-aspiration cohort (28.0% versus 12.2%, p = 0.031). In our multivariable model, only the administration of succinylcholine was significant and was associated with lower probability of aspiration pneumonia (odds ratio 0.56).

CONCLUSION

Overall, the incidence of aspiration pneumonia was low in our cohort. The administration of succinylcholine was associated with a lower odds of developing aspiration pneumonia.

A prospective assessment of the time required to obtain one unit of fresh whole blood by civilian phlebotomists and Army laboratory technicians (68 K)

BACKGROUND

Resuscitation with blood products improves survival after major hemorrhage. Blood product administration at or near the point-of-injury (POI) amplifies this benefit. Size, weight, and cold-chain management challenges all limit the amount of blood medics can carry. Warm fresh whole blood (WFWB) transfusions from a pre-screened donor within the unit represent an alternative source of blood at the POI. We measured the time required for civilian and Army technicians performing phlebotomy frequently to obtain one unit of blood to serve as a goal metric for combat medics being trained in this skill.

METHODS

We gathered demographic and experience data along with proportion of first intravenous cannulation attempt success, time to blood flow initiated, and time to unit draw complete.

RESULTS

We prospectively enrolled 12 civilian phlebotomy technicians and 10 Army laboratory technicians performing whole blood collections on 50 and 68 donors respectively. The mean time from setup to needle insertion was 3.7 min for civilians versus 4.2 min for Army technicians. The mean time from blood flowing to the bag being full was 10.7 min versus 8.4 min for civilians versus Army technicians respectively. The mean bag weights were 514 g versus 522 g. First-pass intravenous cannulation success was 96% versus 98% respectively.

CONCLUSIONS

We found a high first intravenous cannulation attempt success among both the civilian and Army technicians. Medians times were <5 min to obtain venipuncture and <11 min to obtain one unit. These findings provide time-based benchmarks for potential use during transfusion training among military medics.

EFFECTS OF SARS COVID-19 POSITIVITY STATUS ON VENOUS THROMBOSIS AND PULMONARY EMBOLISM RATES IN TRAUMA PATIENTS

ABSTRACT

Introduction : COVID-19-induced coagulopathy (CIC) can increase the risk of thromboembolism without underlying clotting disorders, even when compared with other respiratory viruses. Trauma has a known association with hypercoagulability. Trauma patients with concurrent COVID-19 infection potentially have an even greater risk of thrombotic events. The purpose of this study was to evaluate venous thromboembolism (VTE) rates in trauma patients with COVID-19. Methods : This study reviewed all adult patients (≥18 years of age) admitted to the Trauma Service from April through November 2020 for a minimum of 48 hours. Patients were grouped based off COVID-19 status and compared for inpatient VTE chemoprophylaxis regimen, thrombotic complications defined as deep vein thrombosis, pulmonary embolism, myocardial infarction, and cerebrovascular accident, intensive care unit (ICU) length of stay, hospital length of stay, and mortality. Results : A total of 2,907 patients were reviewed and grouped into COVID-19-positive (n = 110) and COVID-19-negative (n = 2,797) groups. There was no difference in terms of receiving deep vein thrombosis chemoprophylaxis or type, but a longer time to initiation in the positive group ( P = 0.0012). VTE occurred in 5 (4.55%) positive and 60 (2.15%) negative patients without a significant difference between the groups, as well as no difference in type of VTE observed. Mortality was higher ( P = 0.009) in the positive group (10.91%). Positive patients had longer median ICU LOS ( P = 0.0012) and total LOS ( P < 0.001). Conclusion : There were no increased rates of VTE complications between COVID-19-positive and -negative trauma patients, despite a longer time to initiation of chemoprophylaxis in the COVID-19-positive group. COVID-19-positive patients had increased ICU LOS, total LOS, and mortality, which are likely due to multifactorial causes but primarily related to their underlying COVID-19 infection.

A prospective assessment of the medic autologous blood transfusion skills for field transfusion preparation

BACKGROUND

Data demonstrate the benefit of blood product administration near point-of-injury (POI). Fresh whole blood transfusion from a pre-screened donor provides a source of blood at the POI when resources are constrained. We captured transfusion skills data for medics performing autologous blood transfusion training.

METHODS

We conducted a prospective, observational study of medics with varying levels of experience. Inexperienced medics were those with minimal or no reported experience learning the autologous transfusion procedures, versus reported experience among special operations medics. When available, medics were debriefed after the procedure for qualitative feedback. We followed them for up to 7 days for adverse events.

RESULTS

The median number of attempts for inexperienced and experienced medics was 1 versus 1 (interquartile range 1-1 for both, p = .260). The inexperienced medics had a slower median time to needle venipuncture access for the donation of 7.3 versus 1.5 min, needle removal after clamping time of 0.3 versus 0.2 min, time to bag preparation of 1.9 versus 1.0 min, time to IV access for reinfusion of 6.0 versus 3.0 min, time to transfusion completion of 17.3 versus 11.0 min, and time to IV removal of 0.9 versus 0.3 min (all p < .05). We noted one administrative safety event in which an allogeneic transfusion occurred. No major adverse events occurred. Qualitative data saturated around the need for quarterly training.

CONCLUSIONS

Inexperienced medics have longer procedure times when training autologous whole blood transfusion skills. This data will help establish training measures of performance for skills optimization when learning this procedure.

Protocol and statistical analysis plan for the PREOXI trial of preoxygenation with noninvasive ventilation vs oxygen mask

Background

Hypoxemia is a common and life-threatening complication during emergency tracheal intubation of critically ill adults. The administration of supplemental oxygen prior to the procedure ("preoxygenation") decreases the risk of hypoxemia during intubation.

Research Question

Whether preoxygenation with noninvasive ventilation prevents hypoxemia during tracheal intubation of critically ill adults, compared to preoxygenation with oxygen mask, remains uncertain.

Study Design and Methods

The PRagmatic trial Examining OXygenation prior to Intubation (PREOXI) is a prospective, multicenter, non-blinded randomized comparative effectiveness trial being conducted in 7 emergency departments and 17 intensive care units across the United States. The trial compares preoxygenation with noninvasive ventilation versus oxygen mask among 1300 critically ill adults undergoing emergency tracheal intubation. Eligible patients are randomized in a 1:1 ratio to receive either noninvasive ventilation or an oxygen mask prior to induction. The primary outcome is the incidence of hypoxemia, defined as a peripheral oxygen saturation <85% between induction and 2 minutes after intubation. The secondary outcome is the lowest oxygen saturation between induction and 2 minutes after intubation. Enrollment began on 10 March 2022 and is expected to conclude in 2023.

Interpretation

The PREOXI trial will provide important data on the effectiveness of noninvasive ventilation and oxygen mask preoxygenation for the prevention of hypoxemia during emergency tracheal intubation. Specifying the protocol and statistical analysis plan prior to the conclusion of enrollment increases the rigor, reproducibility, and interpretability of the trial.

Clinical trial registration number

NCT05267652.

Adherence to a Balanced Approach to Massive Transfusion in Combat Casualties

BACKGROUND

Hemorrhage is the most common cause of potentially preventable death on the battlefield. Balanced resuscitation with plasma, platelets, and packed red blood cells (PRBCs) in a 1:1:1 ratio, if whole blood (WB) is not available, is associated with optimal outcomes among patients with hemorrhage. We describe the use of balanced resuscitation among combat casualties undergoing massive transfusion.

MATERIALS AND METHODS

We conducted a secondary analysis of data from the Department of Defense Trauma Registry (DODTR) spanning encounters from January 1, 2007, to March 17, 2020. We included all casualties who received at least 10 units of either PRBCs or WB. We categorized casualties as recipients of plasma-balanced resuscitation if the ratio of plasma to PRBC units was 0.8 or greater; similarly, we defined platelet-balanced resuscitation as a ratio of platelets to PRBC units of 0.8 or greater. We portrayed these populations using descriptive statistics and compared characteristics between non-balanced and balanced resuscitation recipients for both plasma and platelets.

RESULTS

We identified 28,950 encounters in the DODTR with documentation of prehospital activity. Massive transfusions occurred for 2,414 (8.3%) casualties, among whom 1,593 (66.0%) received a plasma-balanced resuscitation and 1,248 (51.7%) received a platelet-balanced resuscitation. During the study period, 962 (39.8%) of these patients received a fully balanced resuscitation with regard to both the plasma:PRBC and platelet:PRBC ratios. The remaining casualties did not undergo a balanced resuscitation.

CONCLUSIONS

While a majority of massive transfusion recipients received a plasma-balanced and/or platelet-balanced resuscitation, fewer patients received a platelet-balanced resuscitation. These findings suggest that more emphasis in training and supply may be necessary to optimize blood product resuscitation ratios.

Improving Outcomes Associated with Prehospital Combat Airway Interventions: An Unrealized Opportunity

BACKGROUND

Airway obstruction is the second leading cause of potentially survivable death on the battlefield. Assessing outcomes associated with airway interventions is important, and temporal trends can reflect the influence of training, technology, the system of care, and other factors. We assessed mortality among casualties undergoing prehospital airway intervention occurring over the course of combat operations during 2007-2019.

METHODS

This is a retrospective analysis of a previously described dataset from the Department of Defense Trauma Registry (DODTR). We included only casualties with documented placement of an endotracheal tube, cricothyrotomy, or supraglottic airway (SGA) in the prehospital setting.

RESULTS

Within the DODTR from January 2007 to December 2019, there were 25,849 adult encounters with documentation of any prehospital activity. Within that group, there were 251 documented cricothyrotomies, 1,147 documented intubations, and 35 documented supraglottic airways placed. Cricothyrotomy recipients had a median age of 25. Within this group, the largest proportion were non-North Atlantic Treaty Organization (NATO) military personnel (35%), were injured by explosives (54%), had a median injury severity score (ISS) of 24, and 60% survived to hospital discharge. Intubation recipients had a median age of 24. Within this group, the largest proportion were non-NATO military personnel (37%), were injured by explosives (57%), had a median ISS of 18, and 76% survived to hospital discharge. SGA recipients had a median age of 28. Within this group, the largest proportion were non-NATO military (37%), were injured by firearms (48%), had a median ISS of 25, and 54% survived to hospital discharge. A downward trend existed in the quantity of all procedures performed during the study period. In both unadjusted and adjusted regression models, we identified no year-to-year differences in survival after prehospital cricothyrotomy or SGA placement. In the unadjusted and adjusted models, we noted a decrease in mortality during the 2007-2008 (odds ratio [OR] for death 0.47, 95% CI 0.26-0.86) and an increase from 2012-2013 (OR 2.10, 95% CI 1.09-4.05) for prehospital intubation.

CONCLUSION

Mortality among combat casualties undergoing prehospital or emergency department airway interventions showed no sustained change during the study period. These findings suggest that advances in airway resuscitation are necessary to achieve mortality improvements in potentially survivable airway injuries in the prehospital setting.

A Contemporary Analysis of Combat-Related Urological Injuries: Data From the Department of Defense Joint Trauma System Data Registry

PURPOSE

There has been little to no literature published on combat-related genitourinary injuries beyond 2013. With the goal of enhancing medical readiness prior to deployment and making recommendations to improve the long-term rehabilitation of service members as they become civilians, we sought to describe the incidence of combat-related genitourinary injuries and interventions from January 01, 2007, to March 17, 2020.

MATERIALS AND METHODS

We conducted a retrospective analysis of the Department of Defense Trauma Registry, which is a prospectively maintained database, for the time between 2007 and 2020. We used predefined search criteria to primarily identify any casualties that arrived at a military treatment facility with urological-based injuries.

RESULTS

The registry contained 25,897 adult casualties, of which 7.2% sustained urological injuries. The median age was 25. Explosive injuries (64%) and firearms (27%) predominated. The median injury severity score was 18 (IQR 10-29). Most patients survived until hospital discharge (94%). The most frequently injured organs were the scrotum (60%), testes (53%), penis (30%), and kidneys (30%). Massive transfusion protocols were activated in 35% of all patients who sustained a urological injury and accounted for 28% of all protocols between 2007 and 2020.

CONCLUSIONS

The incidence of genitourinary trauma persistently increased for both military and civilian personnel as the U.S. remained actively engaged in major military conflicts during this period. Patients with genitourinary trauma in this data set were often associated with high injury severity scores and required an increased number of immediate and long-term resources for survival and rehabilitation.

DirEct versus VIdeo LaryngosCopE (DEVICE): protocol and statistical analysis plan for a randomised clinical trial in critically ill adults undergoing emergency tracheal intubation

INTRODUCTION

Among critically ill patients undergoing orotracheal intubation in the emergency department (ED) or intensive care unit (ICU), failure to visualise the vocal cords and intubate the trachea on the first attempt is associated with an increased risk of complications. Two types of laryngoscopes are commonly available: direct laryngoscopes and video laryngoscopes. For critically ill adults undergoing emergency tracheal intubation, it remains uncertain whether the use of a video laryngoscope increases the incidence of successful intubation on the first attempt compared with the use of a direct laryngoscope.

METHODS AND ANALYSIS

The DirEct versus VIdeo LaryngosCopE (DEVICE) trial is a prospective, multicentre, non-blinded, randomised trial being conducted in 7 EDs and 10 ICUs in the USA. The trial plans to enrol up to 2000 critically ill adults undergoing orotracheal intubation with a laryngoscope. Eligible patients are randomised 1:1 to the use of a video laryngoscope or a direct laryngoscope for the first intubation attempt. The primary outcome is successful intubation on the first attempt. The secondary outcome is the incidence of severe complications between induction and 2 min after intubation, defined as the occurrence of one or more of the following: severe hypoxaemia (lowest oxygen saturation <80%); severe hypotension (systolic blood pressure <65 mm Hg or new or increased vasopressor administration); cardiac arrest or death. Enrolment began on 19 March 2022 and is expected to be completed in 2023.

ETHICS AND DISSEMINATION

The trial protocol was approved with waiver of informed consent by the single institutional review board at Vanderbilt University Medical Center and the Human Research Protection Office of the Department of Defense. The results will be presented at scientific conferences and submitted for publication in a peer-reviewed journal.

TRIAL REGISTRATION NUMBER

ClinicalTrials.gov Registry (NCT05239195).

A Retrospective Analysis of Combat Injury Patterns and Prehospital Interventions Associated with the Development of Sepsis

BACKGROUND

Combat injury related wound infections are common. Untreated, these wound infections may progress to sepsis and septic shock leading to increased morbidity and mortality rates. Understanding infectious complications, patterns, progression, and correlated prehospital interventions are vital to understand the development of sepsis. We aim to analyze demographics, injury patterns, and interventions associated with sepsis in battlefield settings.

MATERIALS AND METHODS

This is a secondary analysis of previously published data from the Department of Defense Trauma Registry (DoDTR) from 2007 to 2020. We searched for casualties diagnosed with sepsis (excluding line-sepsis) throughout their initial hospitalization. Regression models were used to seek associations.

RESULTS

Our initial request yielded 28,950 encounters, of which 25,654 (88.6%) were adults that met inclusion, including 243 patients (0.9%) diagnosed with sepsis. Patients included US military (34%), non-North Atlantic Treaty Organization (NATO) military (33%) and humanitarian (30%) groups. Patients diagnosed with sepsis had a significantly lower survival rate than non-septic patients (78.1% vs. 95.7%, p < 0.001). There was no significant difference in administration of prehospital antibiotics between septic and the general populations (10.6% vs. 12.3%, p = 0.395). Prehospital intraosseous access (OR 1.56, 95% CI 1.27-1.91, p = 0.207) and packed red cell administration (1.63, 1.24-2.15, 0.029) were the interventions most associated with sepsis.

CONCLUSIONS

Sepsis occurred infrequently in the DoDTR when evacuation from battlefield is not delayed, but despite increased intervention frequency, developing sepsis demonstrates a significant drop in survival rates. Future research would benefit from the development of risk mitigation measures.

A Conceptual Framework for Non-Military Investigators to Understand the Joint Roles of Medical Care in the Setting of Future Large Scale Combat Operations

As the wars in Iraq and Afghanistan end, the US military has begun to transition to the multi-domain operations concept with preparation for large scale combat operations against a near-peer adversary. In large scale combat operations, the deployed trauma system will likely see challenges not experienced during the Global War on Terrorism. The development of science and technology will be critical to close existing capability gaps and optimize casualty survival. This review comprises a framework of deployed trauma care to provide nonmilitary investigators a general understanding of our deployed trauma care system. Trauma care begins at the Role 1 which encompasses all care from the point of injury and the battalion aid station, through transport to the Role 2 or forward staged mobile surgical team such as a Forward Resuscitative Surgical Detachment. Role 1 point of injury care approximates the care delivered by Emergency Medical Services (EMS) personnel. The Battalion Aid Station approximates the care available at a freestanding emergency center with significant differences in training level of the providers, number of beds, and diagnostic capabilities. Role 2 medical care is part of an area support medical company with surgical capabilities. The Role 2 represents the first role of care which provides damage control surgery. This capability approximates a small community hospital with the primary difference being limited patient holding capacity and reduced diagnostic equipment. The Role 3 field hospital is the largest military treatment facility in the deployed setting. The Role 3 approximates a civilian level 2 trauma center with smaller holding capabilities and diagnostic abilities limited to that of a computed tomography (CT) scanner and less.

Patterns of Palliation: A Review of Casualties That Received Pain Management Before Reaching Role 2 in Afghanistan

INTRODUCTION

Battlefield pain management changed markedly during the first 20 years of the Global War on Terror. Morphine, long the mainstay of combat analgesia, diminished in favor of fentanyl and ketamine for military pain control, but the options are not hemodynamically or psychologically equivalent. Understanding patterns of prehospital analgesia may reveal further opportunities for combat casualty care improvement.

MATERIALS AND METHODS

Using Department of Defense Trauma Registry data for the Afghanistan conflict from 2005 to 2018, we examined 2,402 records of prehospital analgesia administration to assess temporal trends in medication choice and proportions receiving analgesia, including subanalysis of a cohort screened for an indication with minimal contraindication for analgesia. We further employed frequency matching to explore the presence of disparities in analgesia by casualty affiliation.

RESULTS

Proportions of documented analgesia increased throughout the study period, from 0% in 2005 to 70.6% in 2018. Afghan casualties had the highest proportion of documented analgesia (53.0%), versus U.S. military (31.9%), civilian/other (23.3%), and non-U.S. military (19.3%). Fentanyl surpassed morphine in the frequency of administration in 2012. The median age of those receiving ketamine was higher (30 years) than those receiving fentanyl (26 years) or nonsteroidal anti-inflammatory drugs (23 years). Among the frequency-matched subanalysis, the odds ratio for ketamine administration with Afghan casualties was 1.84 (95% CI, 1.30-2.61).

CONCLUSIONS

We observed heterogeneity of prehospital patient care across patient affiliation groups, suggesting possible opportunities for improvement toward an overall best practice system. General increase in documented prehospital pain management likely reflects efforts toward complete documentation, as well as improved options for analgesia. Current combat casualty care documentation does not include any standardized pain scale.

Antarctic Evacuation: A Retrospective Epidemiological Study of Medical Evacuations on US Military Aircraft in Antarctica

BACKGROUND

The international community has shown increasing interest in the Arctic and Antarctic due to the value polar regions have in terms of environmental research, natural resources, and national defense. The US Government maintains several permanent research and military facilities in polar regions. Medical evacuation (MEDEVAC) from these facilities can be limited for prolonged periods of time due to their extreme climates. Published data regarding MEDEVACs from these facilities is extremely limited.

METHODS

Evacuations on military aircraft registered in the Transportation Command Regulation and Command and Control Evacuation System (TRAC2ES) database in a previously de-identified dataset were queried for events from McMurdo, Antarctica. The data was analyzed to determine the number of evacuations, reasons for evacuation, and additional demographic data.

RESULTS

There were 31 evacuations from McMurdo Station and Scott Amundsen South Pole Station for 29 unique patients recorded in the available TRAC2ES dataset. Reasons for evacuation included traumatic brain/head injury, behavioral health concerns, extremity injuries, pregnancy, and various other medical/surgical concerns.

CONCLUSIONS

MEDEVAC was typically required for advanced diagnostic/treatment modalities or if a patient could no longer fulfill his/her duties. Most evacuations were not directly related to environmental exposure. Given the climate in polar regions can preclude timely evacuation for large periods of time, the need for evacuation must be anticipated and mitigated whenever possible. Better data is needed to guide staffing and mission planning in this remote location.

Hyperoxia is associated with a greater risk for mortality in critically ill traumatic brain injury patients than in critically ill trauma patients without brain injury

OBJECTIVE

The role of hyperoxia in patients with traumatic brain injury (TBI) remains controversial. The objective of this study was to determine the association between hyperoxia and mortality in critically ill TBI patients compared to critically ill trauma patients without TBI.

DESIGN

Secondary analysis of a multicenter retrospective cohort study.

SETTING

Three regional trauma centers in Colorado, USA, between October 1, 2015, and June 30, 2018.

PATIENTS

We included 3464 critically injured adults who were admitted to an intensive care unit (ICU) within 24 h of arrival and qualified for inclusion into the state trauma registry. We analyzed all available SpO2 values during the first seven ICU days. The primary outcome was in-hospital mortality. Secondary outcomes included the proportion of time spent in hyperoxia (defined as SpO2 > 96%) and ventilator-free days.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

In-hospital mortality occurred in 163 patients (10.7%) in the TBI group and 101 patients (5.2%) in the non-TBI group. After adjusting for ICU length of stay, TBI patients spent a significantly greater amount of time in hyperoxia versus non-TBI patients (p = 0.024). TBI status significantly modified the effect of hyperoxia on mortality. At each specific SpO2 level, the risk of mortality increases with increasing FiO2 for both patients with and without TBI. This trend was more pronounced at lower FiO2 and higher SpO2 values, where a greater number of patient observations were obtained. Among patients who required invasive mechanical ventilation, TBI patients required significantly more days of ventilation to day 28 than non-TBI patients.

CONCLUSIONS

Critically ill trauma patients with a TBI spend a greater proportion of time in hyperoxia compared to those without a TBI. TBI status significantly modified the effect of hyperoxia on mortality. Prospective clinical trials are needed to better assess a possible causal relationship.

An Assessment of Casualties Undergoing Delayed Surgical Intervention in the Combat Setting

INTRODUCTION

The US military is transitioning into a posture preparing for large-scale combat operations in which delays in evacuation may become common. It remains unclear which casualty population can have their initial surgical interventions delayed, thus reducing the evacuation demands.

METHODS

We performed a secondary analysis of a previously described dataset from the Department of Defense Trauma Registry (DODTR) focused on casualties who received prehospital care. In this, we sought to determine (1) of those who underwent operative intervention, the proportion of surgeries occurring ≥3 days post-injury, and (2) of those who underwent early versus delayed surgery, the proportions who required blood products.

RESULTS

There were 6,558 US military casualties who underwent surgical intervention-6,224 early (less than 3 days from injury) and 333 delayed (≥ 3 days from injury). The median Injury Severity Score (ISS) was higher in the early cohort (10 versus 6, p is less than 0.001). Serious injuries to the head were more common in the early cohort (12% versus 5%, p is less than 0.001), as were the thorax (13% versus 9%, p=0.041), abdomen (10% versus 5%, p=0.001), extremities (37% versus 14%, p is less than 0.001), and skin (4% versus less than 1%, p=0.001). Survival to discharge was lower in the early cohort (97% versus 100%, p is less than 0.001). Mean whole blood consumption was higher in the early cohort (0.5 versus 0 units, p is less than 0.001), as was packed red blood cells (6.3 versus 0.5, p is less than 0.001), platelets (0.9 versus 0, p is less than 0.001), and fresh frozen plasma (4.5 versus 0.2, p is less than 0.001). The administration of any units of packed red blood cells and whole blood was higher for the early cohort (37% versus 7%, p is less than 0.001), as was a ≥3 units threshold (30% versus 3%, p is less than 0.001), and ≥10 units threshold (18% versus 1%, p is less than 0.001).

CONCLUSIONS

Few combat casualties underwent delayed surgical interventions defined as ≥3 days post injury, and only a small number of casualties with delayed surgical intervention received blood products. Casualties who received early surgical intervention were more likely to have higher injury severity scores, and more likely to receive blood.

Tranexamic Acid Improves Survival in the Setting of Severe Head Injury in Combat Casualties

INTRODUCTION

Approximately 1.7 million people sustain traumatic brain injuries (TBI) annually in the US. To reduce morbidity and mortality, management strategies aim to control progressive intracranial bleeding. This study analyzes the association between Tranexamic Acid (TXA) administration and mortality among casualties within the Department of Defense Trauma Registry, specifically focusing on subsets of patients with varying degree of head injury severities.

METHODS

Besides descriptive statistics, we used inverse probability weighted (for age, military service category, mechanism of injury, total units of blood units administered), and injury severity (ISS) and Abbreviated Injury Scale (AIS) head score adjusted generalized linear models to analyze the association between TXA and mortality. Specific subgroups of interest were increasing severities of head injury and further stratifying these by Glasgow Coma Score of 3-8 and severe overall bodily injuries (ISS>=15).

RESULTS

25,866 patients were included in the analysis. 2,352 (9.1%) received TXA and 23,514 (90.9%) did not receive TXA. Among those with ISS>=15 (n=6,420), 21.2% received TXA. Among those with any head injury (AIS head injury severity score>=1; n=9,153), 7.2% received TXA. The median ISS scores were greater in the TXA versus no-TXA group (17 versus 6). Weighted and adjusted models showed overall, there was 25% lower mortality risk between those who received TXA at any point and those who did not (OR:0.75, 95% CI: 0.59, 0.95). Further, as the AIS severity score increased from >=1 (1.08; 0.80, 1.47) to >=5 (0.56; 0.33, 0.97), the odds of mortality decreased.

CONCLUSIONS

TXA may potentially be beneficial in patients with severe head injuries, especially those with severe overall injury profiles. There is a need of definitive studies to confirm this association.

Clinical Assessment of Low Calcium In traUMa (CALCIUM)

Major trauma frequently occurs in the deployed, combat setting and is especially applicable in the recent conflicts with explosives dominating the combat wounded. In future near-peer conflicts, we will likely face even more profound weapons including mortars and artillery. As such, the number of severely wounded will likely increase. Hypocalcemia frequently occurs after blood transfusions, secondary to the preservatives in the blood products; however, recent data suggests major trauma in and of itself is a risk factor for hypocalcemia. Calcium is a major ion involved in heart contractility; thus, hypocalcemia can lead to poor contractility. Smaller studies have linked hypocalcemia to worse outcomes, but it remains unclear what causes hypocalcemia and if intervening could potentially save lives. The objective of this study is to determine the incidence of hypocalcemia on hospital arrival and the association with survival. We are seeking to address the following scientific questions, (1) Is hypocalcemia present following traumatic injury prior to transfusion during resuscitation? (2) Does hypocalcemia influence the amount of blood products transfused? (3) To what extent is hypocalcemia further exacerbated by transfusion? (4) What is the relationship between hypocalcemia following traumatic injury and mortality? We will conduct a multicenter, prospective, observational study. We will gather ionized calcium levels at 0, 3, 6, 12, 18, and 24 hours as part of scheduled calcium measurements. This will ensure we have accurate data to assess the early and late effects of hypocalcemia throughout the course of resuscitation and hemorrhage control. These data will be captured by a trained study team at every site. Our findings will inform clinical practice guidelines and optimize the care delivered in the combat and civilian trauma setting. We are seeking 391 patients with complete data to meet our a priori inclusion criteria. Our study will have major immediate short-term findings including risk prediction modeling to assess who is at risk for hypocalcemia, data assessing interventions associated with the incidence of hypocalcemia, and outcome data including mortality and its link to early hypocalcemia.

Tranexamic Acid Improves Survival in the Setting of Severe Head Injury in Combat Casualties

INTRODUCTION

Approximately 1.7 million people sustain traumatic brain injuries (TBI) annually in the US. To reduce morbidity and mortality, management strategies aim to control progressive intracranial bleeding. This study analyzes the association between Tranexamic Acid (TXA) administration and mortality among casualties within the Department of Defense Trauma Registry, specifically focusing on subsets of patients with varying degree of head injury severities.

METHODS

Besides descriptive statistics, we used inverse probability weighted (for age, military service category, mechanism of injury, total units of blood units administered), and injury severity (ISS) and Abbreviated Injury Scale (AIS) head score adjusted generalized linear models to analyze the association between TXA and mortality. Specific subgroups of interest were increasing severities of head injury and further stratifying these by Glasgow Coma Score of 3-8 and severe overall bodily injuries (ISS>=15).

RESULTS

25,866 patients were included in the analysis. 2,352 (9.1%) received TXA and 23,514 (90.9%) did not receive TXA. Among those with ISS>=15 (n=6,420), 21.2% received TXA. Among those with any head injury (AIS head injury severity score>=1; n=9,153), 7.2% received TXA. The median ISS scores were greater in the TXA versus no-TXA group (17 versus 6). Weighted and adjusted models showed overall, there was 25% lower mortality risk between those who received TXA at any point and those who did not (OR:0.75, 95% CI: 0.59, 0.95). Further, as the AIS severity score increased from >=1 (1.08; 0.80, 1.47) to >=5 (0.56; 0.33, 0.97), the odds of mortality decreased.

CONCLUSIONS

TXA may potentially be beneficial in patients with severe head injuries, especially those with severe overall injury profiles. There is a need of definitive studies to confirm this association.

Expert Consensus Panel Recommendations for Selection of the Optimal Supraglottic Airway Device for Inclusion to the Medic's Aid Bag

INTRODUCTION

Airway obstruction is the second leading cause of potentially survivable death on the battlefield. The Committee on Tactical Combat Casualty Care (CoTCCC) has evolving recommendations for the optimal supraglottic airway (SGA) device for inclusion to the medics' aid bag.

METHODS

We convened an expert consensus panel consisting of a mix of 8 prehospital specialists, emergency medicine experts, and experienced combat medics, with the intent to offer recommendations for optimal SGA selection. Prior to meeting, we independently reviewed previously published studies conducted by our study team, conducted a virtual meeting, and summarized the findings to the panel. The studies included an analysis of end-user after action reviews, a market analysis, engineering testing, and prospective feedback from combat medics. The panel members then made recommendations regarding their top 3 choices of devices including the options of military custom design. Simple descriptive statistics were used to analyze panel recommendations.

RESULTS

The preponderance (7/8, 88%) of panel members recommended the gel-cuffed SGA, followed by the self-inflating-cuff SGA (5/8, 62%) and laryngeal tube SGA (5/8, 62%). Panel members expressed concerns primarily related to the (1) devices' tolerance for the military environment, and (2) ability to effectively secure the gel-cuffed SGA and the self-inflating-cuff SGA during transport.

CONCLUSIONS

A preponderance of panel members selected the gel-cuff SGA with substantial feedback highlighting the need for military-specific customizations to support the combat environment needs.