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.

Herbivory and warming interact in opposing patterns of covariation between arctic shrub species at large and local scales.

A major challenge in predicting species' distributional responses to climate change involves resolving interactions between abiotic and biotic factors in structuring ecological communities. This challenge reflects the classical conceptualization of species' regional distributions as simultaneously constrained by climatic conditions, while by necessity emerging from local biotic interactions. A ubiquitous pattern in nature illustrates this dichotomy: potentially competing species covary positively at large scales but negatively at local scales. Recent theory poses a resolution to this conundrum by predicting roles of both abiotic and biotic factors in covariation of species at both scales, but empirical tests have lagged such developments. We conducted a 15-y warming and herbivore-exclusion experiment to investigate drivers of opposing patterns of covariation between two codominant arctic shrub species at large and local scales. Climatic conditions and biotic exploitation mediated both positive covariation between these species at the landscape scale and negative covariation between them locally. Furthermore, covariation between the two species conferred resilience in ecosystem carbon uptake. This study thus lends empirical support to developing theoretical solutions to a long-standing ecological puzzle, while highlighting its relevance to understanding community compositional responses to climate change.

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.

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.

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.

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.

Livestock impacts on an iconic Namib Desert plant are mediated by abiotic conditions.

Resolving the relative contributions of top-down versus bottom-up drivers of vegetation dynamics is a major challenge in drylands. In the coming decades, growing livestock populations and shifts in water availability will simultaneously impact many arid systems, but a lack of empirical data on plant responses to these pressures limits understanding of how plants will respond. Here, we combine ground and drone observations from an herbivore exclosure experiment to identify ungulate visitation patterns and their impacts on the cover and melon production of !nara (Acanthosicyos horridus), a large, long-lived desert plant in the hyper-arid Namib Desert. !Nara are of key ecological, social, and economic importance to Namib ecosystems and to the local Topnaar people. At our study site, we find that among native and domestic herbivores, free-ranging donkeys have the largest impact on !nara cover and melon production. !Nara cover was negatively affected by herbivores close to the desert-ephemeral river ecotone during a dry period, whereas !nara cover increased on all plants across the landscape during a wetter period, regardless of herbivore access. !Nara near the river channel and those protected from herbivores had more mature melons, particularly during the wetter period. At this site, the potential for conflict between Topnaar !nara melon harvesting and pastoral practices varies with a plant's distance from the river and prevailing abiotic conditions. This work advances monitoring approaches and adds empirical support to the understanding that top-down and bottom-up regulation of plant dynamics varies with spatiotemporal context, even within landscapes.

A new definition for massive transfusion in the modern era of whole blood resuscitation.

BACKGROUND: Multiple thresholds are defined to identify patients at risk of death from hemorrhage, including massive transfusion (MT), critical administration threshold (CAT), and resuscitation intensity (RI). All fail to account for the use of whole blood (WB). We hypothesized that a definition including WB transfusion would better predict early mortality following trauma. METHODS: This is a retrospective review of all trauma patients with activation of the MT protocol from December 2018 to February 2020. Combinations of WB, RBCs, and fresh frozen plasma (FFP) units transfused during the initial hour of resuscitation were compared using receiver operating characteristic and area under the receiver curve (AUC) for 3- and 6-h mortality. WB massive transfusion (WB MT) score was defined as the sum of each unit RBC plus three times each unit of WB transfused within the first hour of resuscitation. RESULTS: There were 235 patients eligible for analysis with 60 resuscitated using ≥1 unit of WB. Overall, 27 and 29 patients died in the first 3 and 6 h, respectively. WB MT ≥7 had the greatest 3-h and 6-h mortality AUC values (0.78 and 0.79, respectively) when compared to MT, CAT, RI4+, and other attempted definitions using units of WB, RBC, and FFP. Compared to WB MT-, WB MT+ patients died at significantly higher rates at 3 h (28.9% vs. 3.1%, p < .001), 24 h (35.5% vs. 5.7%, p < .001), and 28 days (42.1% vs. 11.9%, p < .001). CONCLUSION: WB MT is the first measure of massive resuscitation to incorporate WB and better identifies early mortality than other definitions.

Perception of risk in massive transfusion as it relates to fetal outcomes: A survey of surgeons and nurses at one American trauma center.

BACKGROUND: The use of blood products early in the resuscitation of bleeding trauma patients is widely accepted, but made difficult by limited supplies of D- red blood cell (RBC)-containing products. Use of D+ RBC-containing products would alleviate this issue, but could lead to alloimmunization. Risk associated with transfusing D+ RBC in emergency bleeding situations is being reconsidered. The level of concern surrounding emergency transfusion as it relates to future fetal harm was surveyed among surgeons and nurses. METHODS: Faculty and staff in the Departments of Surgery and Nursing were surveyed on the risks of receiving an emergency RBC transfusion and the subsequent potential for fetal harm. Answers were grouped as likely to accept (likely/very likely) or refuse transfusion (unlikely/very unlikely). Participants were compared by sex, and women by child-bearing age, ([15-50 years] vs. [>50 years]). RESULTS: Ninety surveys were initiated with 76 fully completed. Male (n = 39) and female (n = 37) respondents were comparable. Most female respondents (30/37, 81%) were of childbearing age. Overall, both males (38/39, 95%) and females (33/37, 89%; p = .19) were likely to accept a transfusion in an emergency. There was no difference in transfusion acceptance if the risk of fetal harm was presented as 1% (p = .73) or 0.1% (p = .51). Most females (34/37, 92%) were not opposed to transfusion even if there was an unspecified risk of future fetal harm. CONCLUSION: Most of the surgeons and nurses who responded would accept a transfusion in an emergency situation even if it might lead to harming a future fetus.

How Does Mission Ground Time Impact on Population Coverage of Aeromedical Retrieval Systems?

BACKGROUND: Aeromedical retrieval is an essential component of contemporary emergency care systems. However, in many locations, ground emergency medical services are dispatched to the scene of an incident first to assess the patient and then call for a helicopter if needed. The time to definitive care therefore includes the helicopter's flight to the scene, flight to the trauma center, and nonflying time. Mission ground time (MGT) includes the time required to get the helicopter airborne, as well as time spent at the scene, packaging and loading the casualty into the aircraft. Estimates of MGT typically vary from 10 to 30 min. The impact of MGT duration on population coverage-the number of residents that could be taken to a trauma center within a set time-is not known. The aim of this study was to compare population coverage for different durations of MGT in a single state. METHODS: Coverage was calculated using elliptical coverage areas ("isochrones") based on the location of helicopter bases and Level I and Level II trauma centers. The calculations were performed using Microsoft Excel, assuming a cruising speed of 133 knots (246 km/h), and mapped using arcGIS. The access time threshold was set at 60 min, and we evaluated MGTs of 10, 15, 20, 25, and 30 min. RESULTS: MGT has a marked impact on population coverage. The effect is, furthermore, not linear. When considering the state's three Level I trauma centers, decreasing MGT from 30 to 10 min increased population coverage from 61.2% to 84.2%. When also considering Level II centers, decreasing MGT from 30 min to 10 min increased coverage by 20%. CONCLUSIONS: Elliptical isochrones, with allowance for MGT, provide realistic estimates of population coverage. MGT significantly impacts the proportion of the population that can be taken to a Level I and/or Level II Trauma Center within a set time. The impact is not linear, reflecting the uneven distribution of the population. Consideration should be given to minimizing MGT to preserve the benefits of aeromedical retrieval.

The Evolution of Blood Transfusion in the Trauma Patient: Whole Blood Has Come Full Circle.

Whole blood transfusion in the United States dates back to the Civil War, and it was widely used in all major conflicts since World War I. To understand our current civilian transfusion practices and to anticipate future changes in trauma resuscitation, it is important to understand the series of decisions that led trauma surgeons away from whole blood resuscitation and toward component therapy. In this review, we examine the historical basis for blood transfusion in trauma and examine the recent literature and future directions pertaining to blood product resuscitation in hemorrhaging patients.

Secondary Overtriage of Trauma Patients: Analysis of Clinical and Geographic Patterns.

BACKGROUND: The purpose of a trauma system is to match patients' needs with hospitals' ability to care for them, recognizing that the highest levels of care cannot be provided in all locations. This means that some patients will need to be transferred from a local facility to a higher level of care. Unnecessary transfers are expensive and inconvenient to patients and families. The aim of this study is to analyze the pattern of secondary transfers in a regional trauma system. METHODS: This is a retrospective analysis. We included patients aged 16 y and older who were transferred to University of Alabama at Birmingham Hospital between 2014 and 2018. We conducted bivariate and multivariate logistic regression analysis to identify clinical and organizational predictors of requiring a critical intervention, early discharge, intensive care unit admission, and mortality. Rather than treating each injury as isolated, we analyzed injury patterns. RESULTS: A total of3824 patients met the inclusion criteria. Of them, 664 patients (17.4%) required a critical intervention, 635 (16.6%) were discharged within 24 h, 1356 (35.5%) were admitted to the intensive care unit, and 172 (4.0%) patients died. Univariate and multivariate analyses revealed many positive associations, with regard to injury pattern, originating center, and insurance status. CONCLUSIONS: There are patterns in the data, and further study is required to understand drivers of secondary overtriage, and how we might be able to address this problem. Reducing the number of unnecessary transfers is a difficult task, which will require engagement at all levels of the trauma system.

Leopard predation on gelada monkeys at Guassa, Ethiopia.

Predation is widely believed to exert strong selective pressure on primate behavior and ecology but is difficult to study and rarely observed. In this study, we describe seven encounters between lone wild leopards (Panthera pardus) and herds of geladas (Theropithecus gelada) over a 6-year period in an intact Afroalpine grassland ecosystem at the Guassa Community Conservation Area, Ethiopia. Three encounters consisted of attempted predation on geladas by leopards, one of which was successful. All three attacks occurred in low-visibility microhabitats (dominated by tussock graminoids, mima mounds, or tall shrubs) that provided leopards with hidden viewsheds from which to ambush geladas. An additional four encounters did not result in an attempted attack but still document the consistently fearful responses of geladas to leopards. In encounters with leopards, geladas typically gave alarm calls (n = 7 of 7 encounters), reduced interindividual distances (n = 5), and collectively fled towards or remained at their sleeping cliffs (n = 7), the only significant refugia in the open-country habitat at Guassa. Geladas did not engage in mobbing behavior towards leopards. Encounters with leopards tended to occur on days when gelada herd sizes were small, raising the possibility that leopards, as ambush hunters, might stalk geladas on days when fewer eyes and ears make them less likely to be detected. We compare the behavioral responses of geladas to leopards at Guassa with those previously reported at Arsi and the Simien Mountains and discuss how gelada vulnerability and responses to leopards compare with those of other primate species living in habitats containing more refugia. Lastly, we briefly consider how living in multilevel societies may represent an adaptive response by geladas and other open-country primates to predation pressure from leopards and other large carnivores.

Correction: Role of heme in lung bacterial infection after trauma hemorrhage and stored red blood cell transfusion: A preclinical experimental study.

[This corrects the article DOI: 10.1371/journal.pmed.1002522.].

The Depth of Sternal Fracture Displacement Is Not Associated With Blunt Cardiac Injury.

BACKGROUND: Little evidence exist associating displaced sternal fractures with blunt cardiac injury (BCI), especially regarding the depth and severity of sternal fracture displacement and risk of BCI. The purpose of this study was to quantify sternal fracture severity by the degree of displacement and to evaluate the association of fracture severity with BCI. MATERIALS AND METHODS: A single institution retrospective review was performed from 2011 to 2014. All adult patients with sternal fracture were identified from the trauma registry, and sternal fracture displacement was quantified as mild (>0 mm, <5 mm), moderate (≥5 mm, <10 mm), or severe (≥10 mm). BCI was diagnosed according to standard AAST grading. Analysis was performed to assess the association of sternal fracture displacement with BCI, which was the primary outcome of interest. RESULTS: Two hundred thirty-five patients with sternal fractures were included in the study. Forty-five percentage of patients suffered a displaced fracture, and 42.6% were diagnosed with BCI. There was no difference in mean fracture displacement when compared to patients without BCI (2.4 versus 1.6 mm, P = 0.07). There was no significant increase in BCI with sternal fracture displacement when compared to patients with nondisplaced fractures (44.3% versus 41.1%, P = 0.62). Neither fracture displacement (OR 1.10, CI 95% 0.65-1.88) nor severe displacement (OR 2.34, CI 95% 0.64-8.54) was associated with significantly increased risk of BCI. CONCLUSIONS: There is no significant association between the depth of sternal fracture displacement and BCI. Further evaluation and management for BCI should be reserved in the absence of additional symptoms or findings.

Complications Associated With Placement of Chest Tubes: A Trauma System Perspective.

BACKGROUND: The insertion of a chest tube is a common procedure in trauma care, and the Advanced Trauma Life Support program teaches the insertion of chest tubes as an essential and life-saving skill. It is also recognized that the insertion of chest tubes is not without risks or complications. The purpose of this study was to evaluate complications of chest tube placement in a level 1 trauma center compared with those placed in surrounding referral hospitals. METHODS: A retrospective matched cohort study of trauma patients was performed between those who underwent chest tube placement at the level 1 trauma center and those with a chest tube placed before transfer to the level 1 center between 2004 and 2013. Conditional logistic regression was used to compare the likelihood of complications and death between chest tube placement groups. RESULTS: Four thousand two hundred and sixteen trauma patients had a chest tube placed at the level 1 center, and 364 patients had a chest tube placed at an outside hospital before transfer. Two hundred and eighty-one patients were matched. Patients with a chest tube placed outside the trauma center had an increased likelihood of malposition (OR 7.2, 95% CI 3.6-14.6), residual hemothorax (OR 6.3, 95% CI 3.4-11.6), residual pneumothorax (OR 6.7, 95% CI 3.9-11.4), and having a second chest tube placed (OR 3.77, 95% CI 2.37-6.01). However, the patients with a chest tube placed outside of the trauma center were also less likely to develop pneumonia (OR 0.32, 95% CI 0.14-0.73). There were no differences in the odds of developing an empyema, the need for video-assisted thoracoscopic surgery, thoracotomy, or death. CONCLUSIONS: There are opportunities for improving the care of patients who require chest tubes at both referring hospitals and the receiving trauma center. Improving the care of patients who require intercostal drainage requires a systems-based approach, focusing on training and quality improvement.

Older Blood Is Associated With Increased Mortality and Adverse Events in Massively Transfused Trauma Patients: Secondary Analysis of the PROPPR Trial.

STUDY OBJECTIVE: The transfusion of older packed RBCs may be harmful in critically ill patients. We seek to determine the association between packed RBC age and mortality among trauma patients requiring massive packed RBC transfusion. METHODS: We analyzed data from the Pragmatic, Randomized Optimal Platelet and Plasma Ratios trial. Subjects in the parent trial included critically injured adult patients admitted to 1 of 12 North American Level I trauma centers who received at least 1 unit of packed RBCs and were predicted to require massive blood transfusion. The primary exposure was volume of packed RBC units transfused during the first 24 hours of hospitalization, stratified by packed RBC age category: 0 to 7 days, 8 to 14 days, 15 to 21 days, and greater than or equal to 22 days. The primary outcome was 24-hour mortality. We evaluated the association between transfused volume of each packed RBC age category and 24-hour survival, using random-effects logistic regression, adjusting for total packed RBC volume, patient age, sex, race, mechanism of injury, Injury Severity Score, Revised Trauma Score, clinical site, and trial treatment group. RESULTS: The 678 patients included in the analysis received a total of 8,830 packed RBC units. One hundred patients (14.8%) died within the first 24 hours. On multivariable analysis, the number of packed RBCs greater than or equal to 22 days old was independently associated with increased 24-hour mortality (adjusted odds ratio [OR] 1.05 per packed RBC unit; 95% confidence interval [CI] 1.01 to 1.08): OR 0.97 for 0 to 7 days old (95% CI 0.88 to 1.08), OR 1.04 for 8 to 14 days old (95% CI 0.99 to 1.09), and OR 1.02 for 15 to 21 days old (95% CI 0.98 to 1.06). Results of sensitivity analyses were similar only among patients who received greater than or equal to 10 packed RBC units. CONCLUSION: Increasing quantities of older packed RBCs are associated with increased likelihood of 24-hour mortality in trauma patients receiving massive packed RBC transfusion (≥10 units), but not in those who receive fewer than 10 units.

Evaluation of "Stop the Bleed" training among K-12 faculty and staff in Alabama.

OBJECTIVES: To evaluate "Stop the Bleed" (STB) training among/K12 personnel in an Alabama school system, and to assess participants' perceived readiness to train peers in STB methods. DESIGN AND SAMPLE: We performed a cross-sectional observational study with a convenience, nonprobability sample of 466 full-time personnel who received STB training. Data were collected using an anonymous online survey. MEASUREMENTS: We asked participants to recall feelings related to STB both prior to and after completing training using a 5-point Likert scale (5 = "Strongly Disagree", 1 = "Strongly Agree"). We used logistic regression to evaluate the association among posttraining feelings and perceived preparedness to train others in STB. RESULTS: Participants were primarily female (78%), aged 41 ± 10 years, who held faculty positions (94%). Results revealed increased knowledge of (4 [IQR 2-4] vs. 2 [1-2], p < .001) and comfort with (4 [2-5] vs. 2 [1-2], p < .001) STB skills. Participants felt more empowered to organize STB training (4 [3-5] vs. 3 [2-4], p < .001); those who felt empowered to organize STB training were eight times more likely to feel capable of teaching STB. CONCLUSIONS: After STB training, K-12 personnel felt empowered to organize additional STB trainings and capable of teaching STB methods to others.

Role of heme in lung bacterial infection after trauma hemorrhage and stored red blood cell transfusion: A preclinical experimental study.

BACKGROUND: Trauma is the leading cause of death and disability in patients aged 1-46 y. Severely injured patients experience considerable blood loss and hemorrhagic shock requiring treatment with massive transfusion of red blood cells (RBCs). Preclinical and retrospective human studies in trauma patients have suggested that poorer therapeutic efficacy, increased severity of organ injury, and increased bacterial infection are associated with transfusion of large volumes of stored RBCs, although the mechanisms are not fully understood. METHODS AND FINDINGS: We developed a murine model of trauma hemorrhage (TH) followed by resuscitation with plasma and leukoreduced RBCs (in a 1:1 ratio) that were banked for 0 (fresh) or 14 (stored) days. Two days later, lungs were infected with Pseudomonas aeruginosa K-strain (PAK). Resuscitation with stored RBCs significantly increased the severity of lung injury caused by P. aeruginosa, as demonstrated by higher mortality (median survival 35 h for fresh RBC group and 8 h for stored RBC group; p < 0.001), increased pulmonary edema (mean [95% CI] 106.4 µl [88.5-124.3] for fresh RBCs and 192.5 µl [140.9-244.0] for stored RBCs; p = 0.003), and higher bacterial numbers in the lung (mean [95% CI] 1.2 × 10(7) [-1.0 × 10(7) to 2.5 × 10(7)] for fresh RBCs and 3.6 × 10(7) [2.5 × 10(7) to 4.7 × 10(7)] for stored RBCs; p = 0.014). The mechanism underlying this increased infection susceptibility and severity was free-heme-dependent, as recombinant hemopexin or pharmacological inhibition or genetic deletion of toll-like receptor 4 (TLR4) during TH and resuscitation completely prevented P. aeruginosa-induced mortality after stored RBC transfusion (p < 0.001 for all groups relative to stored RBC group). Evidence from studies transfusing fresh and stored RBCs mixed with stored and fresh RBC supernatants, respectively, indicated that heme arising both during storage and from RBC hemolysis post-resuscitation plays a role in increased mortality after PAK (p < 0.001). Heme also increased endothelial permeability and inhibited macrophage-dependent phagocytosis in cultured cells. Stored RBCs also increased circulating high mobility group box 1 (HMGB1; mean [95% CI] 15.4 ng/ml [6.7-24.0] for fresh RBCs and 50.3 ng/ml [12.3-88.2] for stored RBCs), and anti-HMGB1 blocking antibody protected against PAK-induced mortality in vivo (p = 0.001) and restored macrophage-dependent phagocytosis of P. aeruginosa in vitro. Finally, we showed that TH patients, admitted to the University of Alabama at Birmingham ER between 1 January 2015 and 30 April 2016 (n = 50), received high micromolar-millimolar levels of heme proportional to the number of units transfused, sufficient to overwhelm endogenous hemopexin levels early after TH and resuscitation. Limitations of the study include lack of assessment of temporal changes in different products of hemolysis after resuscitation and the small sample size precluding testing of associations between heme levels and adverse outcomes in resuscitated TH patients. CONCLUSIONS: We provide evidence that large volume resuscitation with stored blood, compared to fresh blood, in mice increases mortality from subsequent pneumonia, which occurs via mechanisms sensitive to hemopexin and TLR4 and HMGB1 inhibition.

A decompositional analysis of firearm-related mortality in the United States, 2001-2012.

Prior literature reporting increased rates of firearm-related homicide and suicide with increasing firearm availability is limited by only examining the availability of firearms, which is only one component of firearm-related mortality. The objective of the current study is to separate the rates into their respective components and determine which components contribute to mortality rate changes. To address the objective, nationally representative data from 2001 to 2012 was collected from a variety of publicly-available sources. Utilizing decompositional methodology, a negative binomial regression was used to estimate rate ratios for the association between the components and year category, and relative contributions of each component were calculated. From 2001 to 2012, the homicide and unintentional mortality rate decreased while the suicide rate increased. The suicide rate was only the firearm prevalence rate. The unintentional mortality rate was a factor of firearm prevalence, injury incidence, and case fatality rate. The homicide rate was a factor of firearm prevalence, violent crime rate, injury incidence, and case fatality rate. The current results suggest that the contributors of changes in firearm-related mortality are multi-faceted. Future studies should perform a decompositional analysis utilizing more granular data to examine whether the currently reported results are true associations or a factor of ecologic fallacy.