The Association Between ADHD in Adolescence and Injury in Early Adulthood in Israel: A Nationwide Historical Cohort Study.

OBJECTIVE: To examine the association between late adolescence ADHD and the risk of serious injury in early adulthood. METHOD: A nationwide cohort study utilizing data from the Military Health Examinations Database for potential military recruits (age 16.5-18 years), cross-referenced with the Israeli National Trauma Registry (2008-2020). Individuals with and without ADHD (mild/severe) were compared for early adulthood injury risk using Cox models. RESULTS: This study compared 76,403 participants with mild ADHD (18.76%) and 330,792 without (81.24%), alongside 2,835 severe ADHD participants (1.11%) versus 252,626 without (98.89%). Adjusted hazard ratios for injury-related hospitalization were 1.27 (95% CI [1.17, 1.37]) for mild ADHD and 1.40 (95% CI [1.09, 1.79]) for severe ADHD, compared to non-ADHD. CONCLUSIONS: Adolescents with ADHD, regardless of severity, had a significantly higher risk of hospitalization due to injury that persists into early adulthood, underscoring the importance of recognizing ADHD as an injury risk and incorporating it into injury prevention strategies.

Toward Smart, Automated Junctional Tourniquets-AI Models to Interpret Vessel Occlusion at Physiological Pressure Points.

Hemorrhage is the leading cause of preventable death in both civilian and military medicine. Junctional hemorrhages are especially difficult to manage since traditional tourniquet placement is often not possible. Ultrasound can be used to visualize and guide the caretaker to apply pressure at physiological pressure points to stop hemorrhage. However, this process is technically challenging, requiring the vessel to be properly positioned over rigid boney surfaces and applying sufficient pressure to maintain proper occlusion. As a first step toward automating this life-saving intervention, we demonstrate an artificial intelligence algorithm that classifies a vessel as patent or occluded, which can guide a user to apply the appropriate pressure required to stop flow. Neural network models were trained using images captured from a custom tissue-mimicking phantom and an ex vivo swine model of the inguinal region, as pressure was applied using an ultrasound probe with and without color Doppler overlays. Using these images, we developed an image classification algorithm suitable for the determination of patency or occlusion in an ultrasound image containing color Doppler overlay. Separate AI models for both test platforms were able to accurately detect occlusion status in test-image sets to more than 93% accuracy. In conclusion, this methodology can be utilized for guiding and monitoring proper vessel occlusion, which, when combined with automated actuation and other AI models, can allow for automated junctional tourniquet application.

Adaptive closed-loop resuscitation controllers for hemorrhagic shock resuscitation.

BACKGROUND: After hemorrhage control, fluid resuscitation is the most important intervention for hemorrhage. Even skilled providers can find resuscitation challenging to manage, especially when multiple patients require care. In the future, attention-demanding medical tasks like fluid resuscitation for hemorrhage patients may be reassigned to autonomous medical systems when availability of skilled human providers is limited, such as in austere military settings and mass casualty incidents. Central to this endeavor is the development and optimization of control architectures for physiological closed-loop control systems (PCLCs). PCLCs can take many forms, from simple table look-up methods to widely used proportional-integral-derivative or fuzzy-logic control theory. Here, we describe the design and optimization of multiple adaptive resuscitation controllers (ARCs) that we have purpose-built for the resuscitation of hemorrhaging patients. STUDY DESIGN AND METHODS: Three ARC designs were evaluated that measured pressure-volume responsiveness using different methodologies during resuscitation from which adapted infusion rates were calculated. These controllers were adaptive in that they estimated required infusion flow rates based on measured volume responsiveness. A previously developed hardware-in-loop test platform was used to evaluate the ARCs implementations across several hemorrhage scenarios. RESULTS: After optimization, we found that our purpose-built controllers outperformed traditional control system architecture as embodied in our previously developed dual-input fuzzy-logic controller. DISCUSSION: Future efforts will focus on engineering our purpose-built control systems to be robust to noise in the physiological signal coming to the controller from the patient as well as testing controller performance across a range of test scenarios and in vivo.

Association Between Profound Shock Signs and Peripheral Intravenous Access Success Rates in Trauma Patients in the Prehospital Scenario: A Retrospective Study.

BACKGROUND: Hemorrhage is the leading cause of preventable death in trauma patients, and establishment of intravenous (IV) access is essential for volume resuscitation, a key component in the treatment of hemorrhagic shock. IV access among patients in shock is generally considered more challenging, although data to support this notion are lacking. METHODS: In this retrospective registry-based study, data were collected from the Israeli Defense Forces Trauma Registry (IDF-TR) regarding all prehospital trauma patients treated by IDF medical forces between January 2020 and April 2022, for whom IV access was attempted. Patients younger than 16 years, nonurgent patients, and patients with no detectable heart rate or blood pressure were excluded. Profound shock was defined as a heart rate >130 or a systolic blood pressure <90 mm Hg, and comparisons were made between patients with profound shock and those not exhibiting such signs. The primary outcome was the number of attempts required for first IV access success, which was regarded as an ordinal categorical variable: 1, 2, 3 and higher and ultimate failure. A multivariable ordinal logistic regression was performed to adjust for potential confounders. Patients' sex, age, mechanism of injury and best consciousness level, as well as type of event (military/nonmilitary), and the presence of multiple patients were included in the ordinal logistic regression multivariable analysis model based on previous publications. RESULTS: Five hundred thirty-seven patients were included, 15.7% of whom were recorded as having signs of profound shock. Peripheral IV access establishment first attempt success rates were higher in the nonshock group, and there was a lower rate of unsuccessful attempts in this group (80.8% vs 67.8% for the first attempt, 9.4% vs 16.7% for the second attempt, 3.8% vs 5.6% for the third and further attempts, and 6% vs 10% unsuccessful attempts, P = .04). In the univariable analysis, profound shock was associated with requirement for an increased number of IV attempts (odds ratio [OR], 1.94; confidence interval [CI], 1.17-3.15). The ordinal logistic regression multivariable analysis demonstrated that profound shock was associated with worse results regarding primary outcome (adjusted odds ratio [AOR], 1.84; CI, 1.07-3.10). CONCLUSIONS: The presence of profound shock in trauma patients in the prehospital scenario is associated with an increased number of attempts required for IV access establishment.

Adopting a culture of remote damage control resuscitation in the military: Insights from the Israel defense forces decade of experience.

BACKGROUND: Remote damage control resuscitation (RDCR) aims to apply the principles of damage control resuscitation to prehospital and austere care, emphasizing early control of compressible hemorrhage, balanced volume resuscitation, and the prevention or correction of coagulopathy, acidosis, hypothermia, and hypocalcemia. Over the past decades, the Israel Defense Forces Medical Corps (IDF-MC) has made significant efforts to integrate the principles of RDCR into prehospital trauma care in the military. STUDY DESIGN AND METHODS: In this article, we reflect on the implementation of RDCR in the prehospital setting by the IDF-MC, sharing successes, challenges, considerations on guideline changes, and their assessment over time. RESULTS: The implementation of RDCR has resulted in changes in clinical practice guidelines and training programs, with increased awareness and adoption of RDCR principles among both medical and non-medical military personnel. The implementation of these principles and adherence to guideline changes have been analyzed using the Israel Defense Forces Trauma Registry. DISCUSSION: By sharing our experiences, we hope to provide valuable insights for other military and civilian organizations seeking to adopt similar protocols for prehospital care. Continuous evaluation and refinement of guidelines and training programs will be essential for ongoing implementation and advancement of RDCR in the prehospital setting.

Prehospital Tranexamic Acid Administration in Pediatric Trauma Patients: A Propensity-Matched Analysis of the Israeli Defense Forces Registry.

OBJECTIVES: Tranexamic acid (TXA) administration confers a survival benefit in bleeding trauma patients; however, data regarding its use in pediatric patients are limited. This study evaluates the prehospital treatment with TXA in pediatric trauma patients treated by the Israel Defense Forces Medical Corps (IDF-MC). DESIGN: Retrospective, cohort study using the Israel Defense Forces registry, 2011-2021. PATIENTS: Pediatric trauma patients less than 18 years old. We excluded patients pronounced dead at the scene. INTERVENTIONS: None. SETTING: All cases of pediatric trauma in the registry were assessed for treatment with TXA. Propensity score matching was used to assess the association between prehospital TXA administration and mortality. MEASUREMENTS AND MAIN RESULTS: Overall, 911 pediatric trauma patients were treated with TXA by the IDF-MC teams; the median (interquartile) age was 10 years (5-15 yr), and 72.8% were male. Seventy patients (7.6%) received TXA, with 52 of 70 (74%) receiving a 1,000 mg dose (range 200-1,000 mg). There were no prehospital adverse events associated with the use of TXA (upper limit of 95% CI for 0/70 is 4.3%). Compared with pediatric patients who did not receive TXA, patients receiving TXA were more likely to suffer from shock (40% vs 10.7%; p < 0.001), sustain more penetrating injuries (72.9% vs 31.7%; p < 0.001), be treated with plasma or crystalloids (62.9% vs 11.4%; p < 0.001), and undergo more lifesaving interventions (24.3% vs 6.2%; p < 0.001). The propensity score matching failed to identify an association between TXA and lesser odds of mortality, although a lack of effect (or even adverse effect) could not be excluded (non-TXA: 7.1% vs TXA: 4.3%, odds ratio = 0.584; 95% CI 0.084-3.143; p = 0.718). CONCLUSIONS: Although prehospital TXA administration in the pediatric population is feasible with adverse event rate under 5%, more research is needed to determine the appropriate approach to pediatric hemostatic resuscitation and the role of TXA in this population.

Manual Pressure Points Technique for Massive Hemorrhage Control-A Prospective Human Volunteer Study.

BACKGROUND: While commonly thought to be effective for management of limb and junctional hemorrhage, the manual pressure points technique was excluded from leading prehospital guidelines over a decade ago following the publication of a single human-volunteers study presenting unfavorable results. This work aimed to re-assess the efficacy and feasibility of the femoral and supraclavicular pressure points technique for temporary hemorrhage control distal to the pressure point. METHODS: A prospective, non-randomized, human volunteer, controlled environment study. In the study 35 healthy male combat medics (age 21.1 ± 1.3 years) received brief training after which they were requested to apply pressure in the femoral and supraclavicular points in attempts to stop regional blood flow, measured distally by Doppler ultrasound. Success rates in achieving flow cessation in under 2 minutes, time required for achievement of flow cessation, and cumulative flow cessation duration within a 3-minute follow-up after initial success were measured. RESULTS: For the supraclavicular point, success rates were 97.1% with a mean time to success of 12.5 (±20.9) seconds, lasting for 76.2% (±23.7) of the follow-up time. For the femoral point, success rates were 100% with a mean time to success of 5.5 (±4.3) seconds, lasting for 98.7% (±3.8) of the follow-up time. CONCLUSIONS: Manual pressure on the femoral and supraclavicular points is an applicable and efficient method for temporary hemorrhage control distal to the pressure point. As such, with additional study, this method may be considered for re-introduction to prehospital care guidelines and training programs.

Isolated limb fractures - the underestimated injury in the Israeli Defence Forces (IDF).

INTRODUCTION: Musculoskeletal injuries dominate warfare-related trauma and differ from civilian settings in higher hospitalization costs, morbidity, and mortality. Partly due to introduction of personal protective equipment in the Israel Defence Force (IDF) to minimize head and torso injuries while the extremities remained unprotected. This study describes military extremity injury patterns, prehospital treatment and injury sequela regarding return-to-duty and disability compensation. METHODS: This retrospective study examined cases of battle and non-battle trauma casualties treated by the IDF Medical Corps from 2013 to 2020. Data from the IDF Trauma Registry (IDF-TR) was merged with The Israeli National Trauma Registry (INTR). Cases with high morbidity discharged from military service were compared with lower morbidity patients who returned to active duty service. RESULTS: Out of 1360 injured soldiers, 280 (20.6%) were found to have isolated limb fractures (ILFs). High morbidity casualties had more open fractures (63% vs. 42%) and higher involvement of lower extremities (79% vs. 58%) (p < 0.001), higher rates of tourniquets use (28% compared to 9%, p < 0.001), external fixation (34% vs. 19%, p < 0.001) and amputations (9% vs. 1%, p = 0.003), required more rehabilitation (34% vs. 7%, p < 0.001), and had 46% medical disabilities compared to 24% with low morbidity (p < 0.001). CONCLUSIONS: ILFs are associated with significant morbidity and disability. High morbidity is associated with high energy, scar-producing, lower-extremity open fractured limbs treated by tourniquets. Future studies should evaluate whether junctional or extremity protective gear is combat feasible and whether introducing Clinical Practice Guidelines to manage suspected limb fractures can decrease morbidity rates and improve return to duty.

Pressure Points Technique for Traumatic Proximal Axillary Artery Hemorrhage: A Case Report.

INTRODUCTION: While the pressure points technique for proximal hemorrhage control is long known, it is not recommended in standard prehospital guidelines based on a study showing the inability to maintain occlusion for over two minutes. MAIN SYMPTOM: This report details a gunshot wound to the left axillary area with complete transection of the axillary artery, leading to profuse junctional hemorrhage and profound hemorrhagic shock. THERAPEUTIC INTERVENTION: Proximal pressure of the subclavian artery was applied against the first rib (the pressure points technique) and maintained for 28 minutes. OUTCOMES: Cessation of apparent bleeding and excellent, enduring physiologic response to blood transfusion were observed. CONCLUSION: The pressure points technique can be life-saving in junctional arterial hemorrhage and should be reconsidered in prehospital guidelines.

Blast Injury Patterns Among Israel Defense Forces Fatalities.

INTRODUCTION: The incidence of blast injuries on the battlefield has risen over the last several decades. In order to improve prevention and treatment, it is essential to understand the severity and bodily distribution of these injuries. This study aims to characterize blast injury patterns among IDF fatalities. MATERIALS AND METHODS: This is a descriptive, retrospective study on postmortem reports of military-blast fatalities between the years 1982 and 2021. Body regions injured according to the Abbreviated Injury Scale (AIS) were described. The frequency of body region injury combinations was mapped, and the correlation between injured body regions was calculated using Pearson's coefficient. Analysis of a subgroup with a postmortem computed tomography (CT-PM) or autopsy was performed, describing severe (AIS ≥ 3) injury patterns. RESULTS: Overall, 222 fatalities suffered from blast injury, with most injuries affecting the upper and lower extremities (63.7% and 66.5%, respectively), followed by the head (57.1%) and the thorax (56.6%). The median number of injured body regions was 4 (interquartile range, 2-5). The most frequent injury combinations were the upper and lower extremities (51%), the upper extremities and the thorax (45%), and the lower extremities and the thorax (41%). In all, 47/222 (21.2%) fatalities had a documented autopsy or CT-PM report. Among the fatalities with CT-PM or autopsy, the head (63.8%) and the thorax (57.4%) were most frequently severely injured (AIS ≥ 3). CONCLUSIONS: Among blast fatalities in the military setting, the extremities were most commonly injured. However, data suggest that the head and thorax are more likely to sustain severe blast injuries resulting in mortality. Blast injuries in this cohort were characterized by concomitant involvement of several regions. Development of protective gear to minimize the multisystem injuries inflicted by blast injuries is warranted and should be focused on distinct types and anatomical distribution of severe blast injuries as reported in this study. LEVEL OF EVIDENCE: Level III, Retrospective analysis.

Hardware-in-Loop Comparison of Physiological Closed-Loop Controllers for the Autonomous Management of Hypotension.

Trauma and hemorrhage are leading causes of death and disability worldwide in both civilian and military contexts. The delivery of life-saving goal-directed fluid resuscitation can be difficult to provide in resource-constrained settings, such as in forward military positions or mass-casualty scenarios. Automated solutions for fluid resuscitation could bridge resource gaps in these austere settings. While multiple physiological closed-loop controllers for the management of hypotension have been proposed, to date there is no consensus on controller design. Here, we compare the performance of four controller types-decision table, single-input fuzzy logic, dual-input fuzzy logic, and proportional-integral-derivative using a previously developed hardware-in-loop test platform where a range of hemorrhage scenarios can be programmed. Controllers were compared using traditional controller performance metrics, but conclusions were difficult to draw due to inconsistencies across the metrics. Instead, we propose three aggregate metrics that reflect the target intensity, stability, and resource efficiency of a controller, with the goal of selecting controllers for further development. These aggregate metrics identify a dual-input, fuzzy-logic-based controller as the preferred combination of intensity, stability, and resource efficiency within this use case. Based on these results, the aggressively tuned dual-input fuzzy logic controller should be considered a priority for further development.

Training Ultrasound Image Classification Deep-Learning Algorithms for Pneumothorax Detection Using a Synthetic Tissue Phantom Apparatus.

Ultrasound (US) imaging is a critical tool in emergency and military medicine because of its portability and immediate nature. However, proper image interpretation requires skill, limiting its utility in remote applications for conditions such as pneumothorax (PTX) which requires rapid intervention. Artificial intelligence has the potential to automate ultrasound image analysis for various pathophysiological conditions. Training models require large data sets and a means of troubleshooting in real-time for ultrasound integration deployment, and they also require large animal models or clinical testing. Here, we detail the development of a dynamic synthetic tissue phantom model for PTX and its use in training image classification algorithms. The model comprises a synthetic gelatin phantom cast in a custom 3D-printed rib mold and a lung mimicking phantom. When compared to PTX images acquired in swine, images from the phantom were similar in both PTX negative and positive mimicking scenarios. We then used a deep learning image classification algorithm, which we previously developed for shrapnel detection, to accurately predict the presence of PTX in swine images by only training on phantom image sets, highlighting the utility for a tissue phantom for AI applications.

Evaluation of an Object Detection Algorithm for Shrapnel and Development of a Triage Tool to Determine Injury Severity.

Emergency medicine in austere environments rely on ultrasound imaging as an essential diagnostic tool. Without extensive training, identifying abnormalities such as shrapnel embedded in tissue, is challenging. Medical professionals with appropriate expertise are limited in resource-constrained environments. Incorporating artificial intelligence models to aid the interpretation can reduce the skill gap, enabling identification of shrapnel, and its proximity to important anatomical features for improved medical treatment. Here, we apply a deep learning object detection framework, YOLOv3, for shrapnel detection in various sizes and locations with respect to a neurovascular bundle. Ultrasound images were collected in a tissue phantom containing shrapnel, vein, artery, and nerve features. The YOLOv3 framework, classifies the object types and identifies the location. In the testing dataset, the model was successful at identifying each object class, with a mean Intersection over Union and average precision of 0.73 and 0.94, respectively. Furthermore, a triage tool was developed to quantify shrapnel distance from neurovascular features that could notify the end user when a proximity threshold is surpassed, and, thus, may warrant evacuation or surgical intervention. Overall, object detection models such as this will be vital to compensate for lack of expertise in ultrasound interpretation, increasing its availability for emergency and military medicine.

Trends in prehospital pain management: two decades of point-of-injury care.

BACKGROUND: Pain control in trauma is an integral part of treatment in combat casualty care. More soldiers injured on the battlefield need analgesics for pain than life-saving interventions (LSIs). Early treatment of pain improves outcomes after injury, while inadequate treatment leads to higher rates of post-traumatic stress disorder (PTSD). OBJECTIVES: To describe the experience of the Israel Defense Forces (IDF) Medical Corps with prehospital use of analgesia. METHODS: All cases documented in the IDF-Trauma Registry between January 1997 and December 2019 were examined. Data collection included analgesia administered, mechanism of injury, wound distribution, and life-saving interventions performed. RESULTS: Of 16,117 patients, 1807 (11.2%) had at least one documented analgesia. Demographics included 91.2% male; median age 21 years. Leading mechanism of injury was penetrating (52.9%). Of injured body regions reported, 46.2% were lower extremity wounds. Most common types of analgesics were morphine (57.2%) and fentanyl (27%). Over the two decades of the study period, types of analgesics given by providers at point of injury (POI) had changed. Fentanyl was introduced in 2013, and by 2019 was given to 39% of patients. Another change was an increase of casualties receiving analgesia from 5-10% until 2010 to 34% by 2019. A total of 824 LSIs were performed on 556 patients (30.8%) receiving analgesia and no adverse events were found in any of the casualties. CONCLUSIONS: Most casualties at POI did not receive any analgesics. The most common analgesics administered were opioids. Over time analgesic administration has gained acceptance and become more commonplace on the battlefield.

BladeShield 101: A Novel Prehospital Digital Wearable Combat Casualty Card.

BACKGROUND: The Israeli Defense Forces-Medical Corps (IDF-MC) focuses on reducing preventable death by improving prehospital trauma care. High quality documentation of care can serve casualty care and to improve future care. Currently, paper casualty cards are used for documentation. Incomplete data acquisition and inadequate data handover are common. To resolve these deficits, the IDF-MC launched the BladeShield 101 project. OBJECTIVES: To assess the quality of casualty care data acquired by comparing standard paper casualty cards with the BladeShield 101. METHODS: The BladeShield 101 system consists of three components: a patient unit that records vital signs and medical care provided, a medical sensor that transmits to the patient unit, and a ruggedized mobile device that allows providers to access and document information. We compared all trauma registries of casualties treated between September 2019 and June 2020. RESULTS: The system was applied during the study period on 24 patients. All data were transferred to the military trauma registry within one day, compared to 72% (141/194) with a paper casualty card (P < 0.01). Information regarding treatment time was available in 100% vs. 43% (P < 0.01) of cases and 98% vs. 67% (P < 0.01) of treatments provided were documented comparing BladeShield 101 with paper cards, respectively. CONCLUSIONS: Using an autonomous system to record, view, deliver, and store casualty information may resolve most current information flow deficits. This solution will ultimately significantly improve individual patient care and systematic learning and development processes.

Is Gender a Risk Factor for Oligoanalgesia in the Military Prehospital Trauma Setting?

BACKGROUND: Pain management is fundamental in the treatment of a trauma casualty. Adequate pain management is associated with decreased long-term morbidity and chronic pain. Nonetheless, pain is frequently not documented nor adequately treated in the prehospital setting, a phenomenon described as oligoanalgesia. Gender bias has been suggested as a risk factor for oligoanalgesia. OBJECTIVES: To examine the association between casualty gender and pain management in the prehospital trauma setting. METHODS: We conducted a retrospective cohort study of the Israel Defense Forces Trauma Registry between 2015 and 2020. Univariable analysis followed by multivariable logistic regression was used to assess the association between casualty gender and pain management. For adult patients for whom gender was known, pain scores were documented. RESULTS: A total of 1044 casualties were included in the study; 894 (85.6%) were male. Females and males differed in several demographic and injury characteristics, including age in years (mean 36 vs. 27.6, P value < 0.001) and injury mechanism (16%% vs. 34.5% penetrating injury, P value < 0.001). Female casualties were less likely to be treated for pain (odds ratio [OR] 0.708, 95% confidence interval [95%CI] 0.5-1, P = 0.05). However, after adjustment for various factors, including pain severity, this association was insignificant (OR 0.748, 95%CI 0.46-1.23, P = 0.25). CONCLUSIONS: In this prehospital study, gender bias in pain management was not apparent. As women's role on the battlefield continues to increase, further studies regarding the role of gender bias in casualty care are warranted.

The Influence of Gender Bias: Is Pain Management in the Field Affected by Health Care Provider's Gender?

INTRODUCTION: Appropriate pain management indicates the quality of casualty care in trauma. Gender bias in pain management focused so far on the patient. Studies regarding provider gender are scarce and have conflicting results, especially in the military and prehospital settings. STUDY OBJECTIVE: The purpose of this study is to investigate the effect of health care providers' gender on pain management approaches among prehospital trauma casualties treated by the Israel Defense Forces (IDF) medical teams. METHODS: This retrospective cohort study included all trauma casualties treated by IDF senior providers from 2015-2020. Casualties with a pain score of zero, age under 18 years, or treated with endotracheal intubation were excluded. Groups were divided according to the senior provider's gender: only females, males, or both female and male. A multivariate analysis was performed to assess the odds ratio of receiving an analgesic, depending on the presence of a female senior provider, adjusting for potential confounders. A subgroup analysis was performed for "delta-pain," defined as the difference in pain score during treatment. RESULTS: A total of 976 casualties were included, of whom 835 (85.6%) were male. Mean pain scores (SD) for the female only, male only, and both genders providers were 6.4 (SD = 2.9), 6.4 (SD = 3.0), and 6.9 (SD = 2.8), respectively (P = .257). There was no significant difference between females, males, or both female and male groups in analgesic treatment, overall and per specific agent. This remained true also in the multivariate model. Delta-pain difference between groups was also not significant. Less than two-thirds of casualties in this study were treated for pain among all study groups. CONCLUSION: This study found no association between IDF Medical Corps providers' gender and pain management in prehospital trauma patients. Further studies regarding disparities in acute pain treatment are advised.

Development and Characterization of an Ex Vivo Testing Platform for Evaluating Automated Central Vascular Access Device Performance.

Access to the central vasculature is critical for hemodynamic monitoring and for delivery of life-saving therapeutics during emergency medicine and battlefield trauma situations but requires skill often unavailable in austere environments. Automated central vascular access devices (ACVADs) using ultrasound and robotics are being developed. Here, we present an ex vivo lower-body porcine model as a testing platform for evaluation of vascular devices and compare its features to commercially available platforms. While the commercially available trainers were simpler to set-up and use, the scope of their utility was limited as they were unable to provide realistic anatomic, physiologic, and sonographic properties that were provided by the ex vivo model. However, the ex vivo model was more cumbersome to set-up and use. Overall, both have a place in the development and evaluation pipeline for ACVADs before testing on live animals, thus accelerating product development and translation.

An Automated Hardware-in-Loop Testbed for Evaluating Hemorrhagic Shock Resuscitation Controllers.

Hemorrhage remains a leading cause of death, with early goal-directed fluid resuscitation being a pillar of mortality prevention. While closed-loop resuscitation can potentially benefit this effort, development of these systems is resource-intensive, making it a challenge to compare infusion controllers and respective hardware within a range of physiologically relevant hemorrhage scenarios. Here, we present a hardware-in-loop automated testbed for resuscitation controllers (HATRC) that provides a simple yet robust methodology to evaluate controllers. HATRC is a flow-loop benchtop system comprised of multiple PhysioVessels which mimic pressure-volume responsiveness for different resuscitation infusates. Subject variability and infusate switching were integrated for more complex testing. Further, HATRC can modulate fluidic resistance to mimic arterial resistance changes after vasopressor administration. Finally, all outflow rates are computer-controlled, with rules to dictate hemorrhage, clotting, and urine rates. Using HATRC, we evaluated a decision-table controller at two sampling rates with different hemorrhage scenarios. HATRC allows quantification of twelve performance metrics for each controller configuration and scenario, producing heterogeneous results and highlighting the need for controller evaluation with multiple hemorrhage scenarios. In conclusion, HATRC can be used to evaluate closed-loop controllers through user-defined hemorrhage scenarios while rating their performance. Extensive controller troubleshooting using HATRC can accelerate product development and subsequent translation.

The association between helicopter emergency medical services and early casualty survival: a nationwide study.

BACKGROUND: Helicopter emergency medical services (HEMS) allow for shorter transport duration in long-distance evacuations and facilitate advanced en-route medical care access. Studies comparing HEMS with ground emergency medical services (GEMS), including the outcome of prehospital mortality, are lacking. OBJECTIVE: This study aimed to evaluate the association between HEMS and early mortality in Israel. SETTING: A retrospective cohort study was conducted of the cross-referenced Israel Defense Forces Trauma Registry and Israel National Trauma Registry databases. OUTCOME MEASURES AND ANALYSIS: Univariable logistic regression was used to assess the association between HEMS and early mortality, defined as mortality within 1 day of the injury. Regression analysis was further performed stratifying by event type (military or civilian) or type of injury (penetrating or nonpenetrating). RESULTS: A total of 2344 casualties were included in the study, of whom 756 (32.3%) were evacuated by air. Early mortality rates were 90/1588 (5.7%) and 37/756 (4.9%) in GEMS and HEMS groups, respectively. Regression analysis found no significant analysis between HEMS and early mortality [OR, 0.86 (95% CI, 0.57-1.26)]. Stratified by event type, a nonsignificant association between HEMS and early mortality was demonstrated for combat [OR, 1.69 (95% CI, 0.79-3.92)] and noncombat [OR, 0.73 (95% CI, 0.4-1.25)] events. HEMS was associated with decreased early mortality among casualties with a penetrating injury [OR, 0.59 (95% CI, 0.34-0.98)] but not associated with early mortality among casualties with a nonpenetrating injury [OR, 0.84 (95% CI, 0.43-1.52)]. CONCLUSION: HEMS was not associated with a decrease in early mortality among trauma casualties in this study encompassing the prehospital and hospital scenes. There was a positive trend and a decrease in mortality from penetrating injuries. Further research to ascertain which casualties benefit from HEMS is warranted and will allow for more precise use of this expensive resource.