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

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

Preferential whole blood transfusion during the early resuscitation period is associated with decreased mortality and transfusion requirements in traumatically injured patients.

Introduction: Whole blood (WB) transfusion represents a promising resuscitation strategy for trauma patients. However, a paucity of data surrounding the optimal incorporation of WB into resuscitation strategies persists. We hypothesized that traumatically injured patients who received a greater proportion of WB compared with blood product components during their resuscitative efforts would have improved early mortality outcomes and decreased transfusion requirements compared with those who received a greater proportion of blood product components. Methods: Retrospective review from our Level 1 trauma center of trauma patients during their initial resuscitation (2019-2022) was performed. WB to packed red blood cell ratios (WB:RBC) were assigned to patients based on their respective blood product resuscitation at 1, 2, 3, and 24 hours from presentation. Multivariable regression models were constructed to assess the relationship of WB:RBC to 4 and 24-hour mortality, and 24-hour transfusion requirements. Results: 390 patients were evaluated (79% male, median age of 33 years old, 48% penetrating injury rate, and a median Injury Severity Score of 27). Overall mortality at 4 hours was 9%, while 24-hour mortality was 12%. A significantly decreased 4-hour mortality was demonstrated in patients who displayed a WB:RBC≥1 at 1 hour (5.9% vs. 12.3%; OR 0.17, p=0.015), 2 hours (5.5% vs. 13%; OR 0.16, p=0.019), and 3 hours (5.5% vs. 13%, OR 0.18, p<0.01), while a decreased 24-hour mortality was displayed in those with a WB:RBC≥1 at 24 hours (7.9% vs. 14.6%, OR 0.21, p=0.01). Overall 24-hour transfusion requirements were significantly decreased within the WB:RBC≥1 cohort (12.1 units vs. 24.4 units, p<0.01). Conclusion: Preferential WB transfusion compared with a balanced transfusion strategy during the early resuscitative period was associated with a lower 4 and 24-hour mortality, as well as decreased 24-hour transfusion requirements, in trauma patients. Future prospective studies are warranted to determine the optimal use of WB in trauma. Level of evidence: Level III/therapeutic.

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

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

Using Telehealth to Improve Access to Trauma Care Among Injured Rural Patients in the US.

This Viewpoint discusses the use of telehealth as an alternative approach to expand access to critical resources for injured US patients arriving at rural hospitals.

Large herbivore diversity slows sea ice-associated decline in arctic tundra diversity.

Biodiversity is declining globally in response to multiple human stressors, including climate forcing. Nonetheless, local diversity trends are inconsistent in some taxa, obscuring contributions of local processes to global patterns. Arctic tundra diversity, including plants, fungi, and lichens, declined during a 15-year experiment that combined warming with exclusion of large herbivores known to influence tundra vegetation composition. Tundra diversity declined regardless of experimental treatment, as background growing season temperatures rose with sea ice loss. However, diversity declined slower with large herbivores than without them. This difference was associated with an increase in effective diversity of large herbivores as formerly abundant caribou declined and muskoxen increased. Efforts that promote herbivore diversity, such as rewilding, may help mitigate impacts of warming on tundra diversity.

Intra-abdominal packing does not increase infection risk or mandate longer presumptive antibiotic therapy.

BACKGROUND: Damage control laparotomy allows for resuscitation and reversal of coagulopathy with improved mortality. In-tra-abdominal packing is often used to limit hemorrhage. Temporary abdominal closure is associated with increased rates of subse-quent intra-abdominal infection. The effect of increased duration of antibiotics is unknown on these infection rates. We sought to determine the role of antibiotics in damage control surgery. METHODS: A retrospective analysis of all trauma patients requiring damage control laparotomy on admission to an ACS verified level one trauma center from 2011 to 2016 was performed. Demographic and clinical data including ability and time to attain primary fascial closure, as well as complication rates, were recorded. The primary outcome measure was intra-abdominal abscess formation following damage control laparotomy. RESULTS: Two-hundred and thirty-nine patients underwent DCS during the study period. A majority were packed (141/239, 59.0%). No differences existed in demographics or injury severity between groups, and infection rates were similar (30.5% vs. 38.8%, P=0.18). Patients with infection were more likely to have suffered gastric injury (23.3% vs. 6.1%, P=0.003) than those without complication. There was no significant association between gram negative and anaerobic (Odds Radio [OR] 0.96, 95% confidence interval [CI] 0.87-1.05) or antifungal therapy (OR 0.98, 95% CI 0.74-1.31) and infection rate, regardless of duration on multivariate regression CONCLUSION: Our study offers the first review of the effect of antibiotic duration on intra-abdominal complications following DCS. Gastric injury was more commonly identified in patients who developed intra-abdominal infection. Duration of antimicrobial therapy does not affect infection rate in patients who are packed following DCS.

The 16-year evolution of a military-civilian partnership: The University of Alabama at Birmingham experience.

BACKGROUND: At the University of Alabama at Birmingham (UAB), a multi-tiered military-civilian partnership (MCP) has evolved since 2006. We aimed to outline this model to facilitate potential replication nationally. METHODS: We performed a comprehensive review of the partnership between UAB, the United States Air Force Special Operations Command, and the Department of Defense (DoD) reviewing key documents and conducting interviews with providers. As a purely descriptive study, this project did not involve any patient data acquisition or analysis and therefore was exempt from institutional review board approval per institutional policy. RESULTS: At the time of this review, six core programs existed targeting training, clinical proficiency, and research. Training: (1) The Special Operations Center for Medical Integration and Development trains up to 144 combat medics yearly. (2) UAB trains one integrated military Surgery resident yearly with two additional civilian-sponsored military residents in Emergency Medicine. (3) UAB's Surgical Critical Care Fellowship had one National Guard member with two incoming Active-Duty, one Reservist and one prior service member in August 2022. Clinical Proficiency: (4) UAB hosts four permanently assigned United States Air Force Special Operations Command Special Operations Surgical Teams composed of general surgeons, anesthesiologists, certified registered nurse anesthetists, surgical technologists, emergency physicians, critical care registered nurses, and respiratory therapists totaling 24 permanently assigned active-duty health care professionals. (5) In addition, two fellowship-trained Air Force Trauma Critical Care Surgeons, one Active-Duty and one Reservist, are permanently assigned to UAB. These clinicians participate fully and independently in the routine care of patients alongside their civilian counterparts. Research: (6) UAB's Division of Trauma and Acute Care Surgery is currently conducting nine DoD-funded research projects totaling $6,482,790, and four research projects with military relevance funded by other agencies totaling $15,357,191. CONCLUSION: The collaboration between UAB and various elements within the DoD illustrates a comprehensive approach to MCP. Replicating appropriate components of this model nationally may aid in the development of a truly integrated trauma system best prepared for the challenges of the future. LEVEL OF EVIDENCE: Economic and Value-based Evaluations; Level IV.

Quantifying the movement, behaviour and environmental context of group-living animals using drones and computer vision.

Methods for collecting animal behaviour data in natural environments, such as direct observation and biologging, are typically limited in spatiotemporal resolution, the number of animals that can be observed and information about animals' social and physical environments. Video imagery can capture rich information about animals and their environments, but image-based approaches are often impractical due to the challenges of processing large and complex multi-image datasets and transforming resulting data, such as animals' locations, into geographical coordinates. We demonstrate a new system for studying behaviour in the wild that uses drone-recorded videos and computer vision approaches to automatically track the location and body posture of free-roaming animals in georeferenced coordinates with high spatiotemporal resolution embedded in contemporaneous 3D landscape models of the surrounding area. We provide two worked examples in which we apply this approach to videos of gelada monkeys and multiple species of group-living African ungulates. We demonstrate how to track multiple animals simultaneously, classify individuals by species and age-sex class, estimate individuals' body postures (poses) and extract environmental features, including topography of the landscape and animal trails. By quantifying animal movement and posture while reconstructing a detailed 3D model of the landscape, our approach opens the door to studying the sensory ecology and decision-making of animals within their natural physical and social environments.

Establishing a core outcomes set for massive transfusion: An Eastern Association for the Surgery of Trauma modified Delphi method consensus study.

BACKGROUND: The management of severe hemorrhage has changed significantly over recent decades, resulting in a heterogeneous description of diagnosis, treatment, and outcomes in the literature, which is not suitable for data pooling. Therefore, we sought to develop a core outcome set (COS) to help guide future massive transfusion (MT) research and overcome the challenge of heterogeneous outcomes reporting. METHODS: Massive transfusion content experts were invited to participate in a modified Delphi study. For Round 1, participants submitted a list of proposed core outcomes. In subsequent rounds, panelists used a 9-point Likert scale to score proposed outcomes for importance. Core outcomes consensus was defined as >85% of scores receiving 7 to 9 and <15% of scores receiving 1 to 3. Feedback and aggregate data were shared between rounds. RESULTS: From an initial panel of 16 experts, 12 (75%) completed three rounds of deliberation to reevaluate variables not achieving predefined consensus criteria. A total of 64 items were considered, with 4 items achieving consensus for inclusion as core outcomes: blood products received in the first 6 hours, 6-hour mortality, time to mortality, and 24-hour mortality. CONCLUSION: Through an iterative survey consensus process, content experts have defined a COS to guide future MT research. This COS will be a valuable tool for researchers seeking to perform new MT research and will allow future trials to generate data that can be used in pooled analyses with enhanced statistical power. LEVEL OF EVIDENCE: Diagnostic Test or Criteria; Level V.

Association of blood product ratios with early mortality in pediatric trauma resuscitation: A time-dependent analysis from the National Trauma Databank.

BACKGROUND: Injured children with severe hemorrhage often receive blood product transfusions with ratios of plasma and platelets to packed red blood cells (PRBCs) approaching 1:1:1. Whether blood product ratios vary during pediatric resuscitation is unknown. This study (1) described precise timing of pediatric blood product administration, (2) characterized changes in blood product ratios over time, and (3) evaluated the association of blood products with early mortality while incorporating time-varying factors. METHODS: Pediatric (younger than 18 years) trauma patients receiving high-volume transfusion (>40 mL/kg total products or >2 U PRBC or whole blood, during first 4 hours) were obtained from the 2017 to 2019 Trauma Quality Improvement Program database. The time of each individual product transfusion was recorded, along with demographics, injury details, and times of death. Patients were assigned to blood product groups at 15-minute intervals: high plasma/PRBC ratio (>1:1) with platelets, high plasma/PRBC ratio (>1:1) without platelets, low plasma/PRBC ratio (<1:1), PRBC only, and whole blood. Cox proportional hazards modeling for 24-hour mortality was performed, including blood product group as a time-varying variable and adjusting for relevant covariates. RESULTS: Of 1,152 included patients (median age, 15 years; 32% penetrating, 28% severe traumatic brain injury [sTBI]), 18% died within 24 hours. During the resuscitation period, the number of patients in high-ratio groups increased over time, and patients switched blood product groups up to six times. There was no significant difference in mortality by blood product group. Among patients with sTBI, there was a strong trend toward lower mortality among high plasma/PRBC without platelets versus high plasma/PRBC with platelets (hazard ratio, 0.55; p = 0.07). CONCLUSION: No significant association of high ratios or whole blood with mortality was seen when time-varying factors were incorporated. The impact of balanced resuscitation strategies, particularly platelet transfusion, may be greatest among patients with sTBI. Optimizing balanced resuscitation for children requires appropriately designed prospective studies. LEVEL OF EVIDENCE: Therapeutic/Care Management; Level IV.

The females have spoken: A patient-centered national survey on the administration of emergent transfusions with the potential for future fetal harm.

BACKGROUND: Traumatic hemorrhage is the leading cause of preventable death. Early in the resuscitation, only RhD-positive red blood cells are likely to be available, which poses a small risk of causing harm to a future fetus if transfused to an RhD-negative females of childbearing age (CBA), that is, 15 to 49 years old. We sought to characterize how the population, in particular females of CBA, felt about emergency blood administration vis-a-vis potential future fetal harm. METHODS: A national survey was performed using Facebook advertisements in three waves from January 2021 to January 2022. The advertisements directed users to the survey site with seven demographic questions and four questions on accepting transfusion with differing probabilities for future fetal harm (none/any/1:100/1:10,000). Acceptance of transfusion questions were scored on 3-point Likert scale (likely/neutral/unlikely). Only completed responses by females were analyzed. RESULTS: Advertisements were viewed 16,600,430 times by 2,169,805 people with 15,396 advertisement clicks and 2,873 surveys initiated. Most (2,256 of 2,873 [79%]) were fully completed. Majority (2,049 of 2,256 [90%]) of respondents were female. Eighty percent of females (1,645 of 2,049) were of CBA. Most females responded "likely" or "neutral" when asked whether they would accept a lifesaving transfusion if the following risk of fetal harm were present: no risk (99%), any risk (83%), 1:100 risk (85%), and 1:10,000 risk (92%). There were no differences between females of CBA versus non-CBA with respect to the likelihood of accepting lifesaving transfusion with any potential for future fetal harm ( p = 0.24). CONCLUSION: This national survey suggests that most females would accept lifesaving transfusion even with the potential low risk of future fetal harm. LEVEL OF EVIDENCE: Prognostic and Epidemiological; Level IV.

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

INTRODUCTION: The use of the extremity tourniquet in military environments has reduced preventable deaths due to exsanguinating hemorrhage, leading to increased use in civilian settings. However, the outcomes of contemporary prehospital tourniquet use in civilian settings are not well-described nationally. The objective of this study was to describe the characteristics and outcomes following prehospital tourniquet use by emergency medical services (EMS) in the United States. METHODS: All trauma activations reported to the National EMS Information System 2019 (NEMSIS) were included. Patients who had ≥1 tourniquet applied were identified. Descriptive analyses were used to compare characteristics between tourniquet and no-tourniquet cohorts. Coarsened exact matching was performed to generate a k2k match (on age, sex, lowest-systolic blood pressure, initial patient acuity, provider's initial impression, injury mechanism, and presence of upper/lower extremity injuries) and used to compare outcomes. Trauma patients who may have potentially benefited from tourniquet application (extremity injury, shock index ≥1 and no documented tourniquet application) were identified. RESULTS: A total of 7,161 tourniquets were applied among 4,571,379 trauma activations (1.6/1000 activations). Patients in the tourniquet cohort were younger (40 ± 18 vs 52 ± 26 mean ± SD years), more hypotensive (16.1% vs. 2.5%) and had higher initial acuity (65.0% critical/emergent vs. 20.6%) [p < 0.01 for all]. A total of 7,074 patients in the tourniquet cohort were matched with 7,074 patients in the non-tourniquet cohort. Post-match analysis revealed that the patients in tourniquet cohort had a higher final acuity (80.8% vs. 75.0%, p < 0.01), lower scene-time (15.4 ± 13.6 vs. 17.0 ± 14.2 mean ± SD minutes, p < 0.01), and higher survival-to-hospital (83.6% vs. 75.1%, p < 0.01). A total of 141,471 trauma patients who may have potentially benefited from tourniquet application were identified. CONCLUSION: Prehospital tourniquet use by EMS in the United States is associated with lower scene-time and improved survivability to hospital. Results indicate that patients might benefit from wider tourniquet use in the civilian prehospital setting.

Ecology, evolution, and conservation of Ethiopia's biodiversity.

Ethiopia is home to one of the richest and most unique assemblages of fauna and flora on the African continent. Contained within its borders are two major centers of endemism, the mesic Roof of Africa (also known as the Ethiopian Highlands) and the arid Horn of Africa, resulting from the country's varied topography and consequent geographic isolation. These centers of endemism are crucial to global conservation as evidenced by their classification within the Eastern Afromontane and Horn of Africa biodiversity hotspots, respectively. Ethiopia's diverse ecosystems and the biodiversity they contain are increasingly threatened by climate change and the growing impacts of Africa's second largest human and largest livestock populations. In this paper, we focus on several key areas of recent and ongoing research on Ethiopian biodiversity that have broadened our understanding of nature and its conservation in Africa. Topics explored include the behavioral ecology of Ethiopia's large social mammals, the ecology and conservation of its unique coffee forests, and Ethiopian approaches to community conservation, fortress conservation, and nature-based solutions. We also highlight the increasing prominence of Ethiopian scientists in studies of the country's biodiversity in recent decades. We suggest promising avenues for future research in evolutionary biology, ecology, systematics, and conservation in Ethiopia and discuss how recent and ongoing work in Ethiopia is helping us better understand and conserve nature in the human-dominated landscapes of Africa and other tropical regions today.

Improving ecological insights from dendroecological studies of Arctic shrub dynamics: Research gaps and potential solutions.

Rapid climate change has been driving changes in Arctic vegetation in recent decades, with increased shrub dominance in many tundra ecosystems. Dendroecological observations of tundra shrubs can provide insight into current and past growth and recruitment patterns, both key components for understanding and predicting ongoing and future Arctic shrub dynamics. However, generalizing these dynamics is challenging as they are highly scale-dependent and vary among sites, species, and individuals. Here, we provide a perspective on how some of these challenges can be overcome. Based on a targeted literature search of dendrochronological studies from 2005 to 2022, we highlight five research gaps that currently limit dendro-based studies from revealing cross-scale ecological insight into shrub dynamics across the Arctic biome. We further discuss the related research priorities, suggesting that future studies could consider: 1) increasing focus on intra- and interspecific variation, 2) including demographic responses other than radial growth, 3) incorporating drivers, in addition to warming, at different spatial and temporal scales, 4) implementing systematic and unbiased sampling approaches, and 5) investigating the cellular mechanisms behind the observed responses. Focusing on these aspects in dendroecological studies could improve the value of the field for addressing cross-scale and plant community-framed ecological questions. We outline how this could be facilitated through the integration of community-based dendroecology and dendroanatomy with remote sensing approaches. Integrating new technologies and a more multidisciplinary approach in dendroecological research could provide key opportunities to close important knowledge gaps in our understanding of scale-dependencies, as well as intra- and inter-specific variation, in vegetation community dynamics across the Arctic tundra.

A mobile observatory powered by sun and wind for near real time measurements of atmospheric, glacial, terrestrial, limnic and coastal oceanic conditions in remote off-grid areas.

Climate change is rapidly altering the Arctic environment. Although long-term environmental observations have been made at a few locations in the Arctic, the incomplete coverage from ground stations is a main limitation to observations in these remote areas. Here we present a wind and sun powered multi-purpose mobile observatory (ARC-MO) that enables near real time measurements of air, ice, land, rivers, and marine parameters in remote off-grid areas. Two test units were constructed and placed in Northeast Greenland where they have collected data from cabled and wireless instruments deployed in the environment since late summer 2021. The two units can communicate locally via WiFi (units placed 25 km apart) and transmit near-real time data globally over satellite. Data are streamed live and accessible from (https://gios.org). The cost of one mobile observatory unit is c. 304.000€. These test units demonstrate the possibility for integrative and automated environmental data collection in remote coastal areas and could serve as models for a proposed global observatory system.

Endotheliopathy is Associated with a 24-hour Fibrinolysis Phenotype Described by Low TEG Lysis and High D-Dimer after Trauma: a Secondary Analysis of the PROPPR Study.

Objectives: Determine associations between biomarkers of endotheliopathy, 24-hour fibrinolysis phenotypes and clinical outcomes after trauma. Background: The vascular endothelium is a critical regulator of hemostasis and organ function. The relationship between markers of endotheliopathy and fibrinolysis following trauma has not been evaluated. Methods: We performed a secondary analysis of prospectively collected biomarker data in the Pragmatic Randomized Optimal Platelet and Plasma Ratios (PROPPR) randomized controlled trial. We stratified subjects by 24-hour thromboelastography (TEG) percent clot lysis (LY30) and plasma D-dimer (DD) levels and evaluated differences in endotheliopathy biomarkers and clinical outcomes between subjects with one of four 24-hour fibrinolysis phenotypes: LY30 0.9-2.9% (LY30norm), LY30 >2.9% (LY30high), LY30 <0.9% and low DD (LY30low+DDlow), and LY30 <0.9% and high DD (LY30low+DDhigh). Results: The analysis included 168 subjects with LY30norm, 32 with LY30high, 147 with LY30low+DDlow and 124 with LY30low+DDhigh. LY30low+DDhigh subjects had greater injury severity and a higher incidence of severe head injury, multiorgan failure (MOF), and mortality than the other phenotypes. All endotheliopathy biomarkers were significantly higher in the LY30low+DDhigh phenotype. Adjusting for injury severity, mechanism and head trauma, 24-hour angiopoietin-2 and soluble thrombomodulin were independently associated with the LY30low+DDhigh phenotype. Both endothelial biomarkers were discriminating for MOF. Subjects with thrombomodulin level >9.5 ng/mL and angiopoietin-2 level >3.6 ng/mL accounted for 64% of subjects who developed MOF. Conclusions: In a multicenter trauma cohort, subjects with a fibrinolysis phenotype characterized by low TEG lysis and elevated DD 24 hours after injury have significantly worse endotheliopathy and clinical outcomes. Our findings support mechanistic evaluations of the role of the endothelium in fibrinolysis dysregulation that may drive late-stage organ injury.

Over-transfusion with blood for suspected hemorrhagic shock is not associated with worse clinical outcomes.

BACKGROUND: We evaluated patient outcomes after early, small volume red blood cell (RBC) transfusion in the setting of presumed hemorrhagic shock. We hypothesized that transfusion with even small amounts of blood would be associated with more complications. STUDY DESIGN AND METHODS: Retrospective review of trauma patients admitted to a Level 1 trauma center between 2016-2021. Patients predicted to require massive transfusion who survived ≥72 h were categorized according to units of RBCs transfused in the first 24 h. A Cox regression model stratified by dichotomized ISS and adjusted for SBP <90 mm Hg and pulse >120 bpm on arrival was used to estimate hazard ratios (HRs) for outcomes of interest. RESULTS: A total of 3121 (24%) received RBC transfusion within the first 24 h. Massive transfusion protocol (MTP) was activated in 38% (1188/3121): 17% received no RBCs, 27.4% 1-3 units, 32.4% 4-9 units, and 22.7% ≥10 units. Mean ISS increased with each category of RBC transfusion. There was no difference in the risk of acute kidney injury (AKI), acute respiratory distress syndrome (ARDS), infection, cardiac arrest, venous thromboembolism or stroke for patients receiving 1-3 units compared to the non-transfused group or 4-9 units group (p > 0.05). Compared to those receiving ≥10 units, the 1-3 units group had a significantly lower risk of AKI, ARDS, and cardiac arrest. DISCUSSION: Early empiric RBC transfusion for presumed hemorrhagic shock may subject patients to potential over-transfusion and end-organ damage. Among patients meeting clinical triggers for MTP, 1-3 units of allogeneic RBCs is not associated with worse outcomes.

Nationwide estimates of the need for prehospital blood products after injury.

INTRODUCTION: Prehospital blood product resuscitation after injury significantly decreases risk of mortality. However, the number of patients who may potentially benefit from this life-saving intervention is currently unknown. The primary objective of this study was to estimate the number of patients who may potentially benefit from prehospital blood product resuscitation after injury in the United States. The secondary objective was to estimate the amount of blood products needed for prehospital resuscitation of injured patients. METHODS: Patients ≥16 years with blunt/penetrating injuries included in National Emergency Medical Services Information System 2019 were identified and classified into four separate cohorts of hemodynamic instability: Cohort 1 (systolic blood pressure [SBP] <90 mmHg), Cohort 2 (SBP <90 and/or heart rate [HR] >120), Cohort 3 (SBP <90 and HR >108 or SBP <70), and Cohort 4 (shock index ≥1). The need for prehospital blood was estimated by multiplying number of patients in each cohort with average number of blood products used for prehospital resuscitation. RESULTS: After exclusions, 3.7 million adult trauma patients were included. The number of patients who may potentially benefit from prehospital blood products was estimated as 89,391 (Cohort 1), 901,346 (Cohort 2), 54,160 (Cohort 3), and 300,475 (Cohort 4). Assuming 1 unit of whole blood is needed per patient, a lower-bound estimate of 54,160 additional whole blood units (0.6% of current collections) will be need for prehospital resuscitation of the injured. CONCLUSIONS: Annually, between 54,000 and 900,000 patients may potentially benefit from prehospital blood product resuscitation after injury in the United States. Prehospital blood utilization and collection of blood products will need to be increased to scale-up this life-saving intervention nationwide.