Austere Environments Research Articles

Ultrasound Gel Alternatives in an Austere Environment

Ultrasound Gel Alternatives in an Austere Environment

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

Traumatic injury with subsequent hemorrhage is one of the leading causes of mortality among military personnel and civilians alike. Posttraumatic hemorrhage accounts for 40% to 50% of deaths in severe trauma patients occurring secondary to direct vessel injury or the development of trauma-induced coagulopathy (TIC). Hyperfibrinolysis plays a major role in TIC and its presence increases a patient's risk of mortality. Early therapeutic intervention with intravenous (IV) tranexamic acid (TXA) prevents development of hyperfibrinolysis and subsequent TIC leading to decreased mortality. However, obtaining IV access in an austere environment can be challenging. In this study, we evaluated the efficacy of intramuscular (IM) versus IV TXA at preventing hyperfibrinolysis in a hemorrhaged swine. Yorkshire cross swine were randomized on the day of study to receive IM or IV TXA or no treatment. Swine were sedated, intubated, and determined to be hemodynamically stable before experimentation. Controlled hemorrhaged was induced by the removal of 30% total blood volume. After hemorrhage, swine were treated with 1,000 mg of IM or IV TXA. Control animals received no treatment. Thirty minutes post-TXA treatment, fibrinolysis was induced with a 50-mg bolus of tissue plasminogen activator. Blood samples were collected to evaluate blood TXA concentrations, blood gases, blood chemistry, and fibrinolysis. Blood TXA concentrations were significantly different between administration routes at the early time points but were equivalent by 20 minutes after injection, remaining consistently elevated for up to 3 hours postadministration. Induction of fibrinolysis resulted in 87.18 ± 4.63% lysis in control animals, compared with swine treated with IM TXA, 1.96 ± 2.66% and 1.5 ± 0.42% lysis in the IV TXA group. In the large swine model of hemorrhage with hyperfibrinolysis, IM TXA is bioequivalent and equally efficacious in preventing hyperfibrinolysis as IV TXA administration.

Role of emergency teleradiology in a mass motorcycle event: the experience of the 2021 International Six Days of Enduro (ISDE).

Provision of healthcare support at mass gathering sporting events is of paramount importance for the success of the event. Many of such events, like motorsports, have been increasingly taking place in remote and austere environments. In these settings, the use of first-line diagnostic tools, such as point of care ultrasound and portable X-ray, could aid in definitive care on the field for patients with minor trauma while also ensuring fast access to the appropriate level of care for patients requiring hospitalization. As part of the ISDE 2021 medical response plan, a field hospital equipped with portable digital X-ray and telemedicine was established. Data on patient admission, triage, treatments, diagnostics, and outcomes were collected for analysis. During the 6-day competition, 79 patients sought medical care at the field hospital, with traumatic injuries accounting for 77% of cases. Of these, 47 were athletes and 32 were non-athletes. The majority (91%) arrived spontaneously, while 9% were transported directly. Upon admission, 68 patients were triaged as non-urgent (code 3) and 11 as urgent (code 2). Of those admitted, 69 received treatment and were discharged at the field hospital, while 10 were transferred elsewhere. Notably, four patients had major trauma, two had isolated fractures, and one needed a CT scan after losing consciousness. Overall, 29 missions were conducted on the race field, including 13 primary transports to local hospitals and 6 to the field hospital. Primary transport was primarily due to major trauma. Among 31 patients who had radiological exams, 11 (35.5%) had traumatic injuries. Of these, 5 were treated with braces and casts and discharged without hospitalization, 3 were advised for post-event care, and 3 were hospitalized. In contrast, patients with negative X-rays received on-site treatment, with 7 able to continue competing. In summary, the successful implementation of portable X-ray machines and teleradiology at remote and austere high-risk sporting events holds great promise for enhancing on-site medical capabilities, allowing clinicians informed decisions, avoiding unnecessary hospitalization, and allowing athletes to continue with their competition. Provided that challenges related to cost, safety, connectivity, and power supply are effectively addressed.

The Perfect Med Bag is One that Doesn't Fall Off a Cliff: A Combat Mass Casualty Case.

Military trauma provides a unique pattern of injuries due to the high velocity, high kinetic energy ammunition utilized, and the high prevalence of blast injury. To further complicate this, military trauma often occurs in austere environments with limited logistical support. Therefore, military medical providers are forced to learn nonstandard techniques and when necessary, practice a level of improvisation not commonly seen in other medical fields. The case presented in this manuscript is a prime example of these challenges. At the onset of fighting both the medic's rucksack, carrying with it the primary source of medical gear and the precious supply of cold-stored blood products are lost. The scenario was further complicated by rough mountainous terrain and a prolonged evacuation time. The medical provider was forced to utilize nonstandard devices such as an improvised junctional tourniquet which used a rock to focus the devices pressure. They also adapted their basic understanding of surgical procedures to conduct a vascular cutdown procedure for wound exposure and effectively pack an otherwise non-compressible wound to a major artery. Despite a significant loss of equipment, the medic and their team were able to successfully care for a number of patients in this mass casualty scenario.

Advancing Readiness Through Military Programs: An Evidence-Based Practice Perspective.

Military nurses comprise the largest percentage of military health care providers. In the current military health care system, they have two roles: (1) Patient care in military treatment facilities (MTFs) and (2) patient care during combat operations. Although in MTFs, the military nurse's roles are similar to those of their civilian counterpart, their roles are unique and varied in the combat operational environment. These combined roles lead to questions regarding readiness training to ensure that nurses are proficient in both MTFs and combat operational settings where treatment requirements may differ. The purpose of this paper is to (1) present the current state of educational readiness programs to maintain a ready medical force that entail formal teaching programs, military-civilian partnerships, and joint exercises of combat simulations, and (2) identify gaps as presented in an evidence-based practice educational panel. On March 11, 2022, TriService Nursing Research Program hosted the virtual First Military Evidence-Based Practice Summit from the Uniformed Services University of the Health Sciences in Bethesda, MD. As part of the summit, an evidence-based practice education panel discussed the availability of current evidence-driven military medical readiness programs and identified gaps in the integration of military readiness for nursing personnel into the Defense Health Agency and Armed Services. The panel participants discussed the separate requirements for training within the MTFs and in combat operational settings. The available training programs identified by the panel were primarily those developed in local MTF settings to meet local needs. Although these programs support the MTFs' peacetime mission, competing roles, limited time, and limited funds contributed to limited preparation of nursing personnel in skills associated with combat-related injuries and illnesses. Prolonged casualty care has become an important focus for the Department of Defense as greater considerations are directed to wartime operations in austere expeditionary environments. Although there is some training available that is specific for prolonged casualty care, the focus has been the adaptation of combat casualty care during contingency operations. A keynote here was the concept that combat casualty care training must include both development of individual skills and integration of the team since maximal care can be achieved only when the individual and the team operate as a unit. A key point was the utility of central repositories for storing information related to training a ready medical force at individual and unit levels and that these repositories could also be used to collect and facilitate the accession of current evidence-based information. Optimal patient care at all levels of the military health system requires training that maximizes individual and unit skills specific to the environment at an MTF or in a combat operational setting. Training must be designed to incorporate evidence-driven knowledge in all military settings with guidance that is specific to the environment. Enhanced communication of evidence-based training and knowledge is an important component of maintaining a ready medical force for broader medical support of combat contingency operations.

Effectiveness ofFDA-cleared Wound Cleansers forDisinfection ofSurgical Surfaces inResource Limited Environments.

Service members experience unique circumstances when providing medical care in austere environments. Some challenges include supply shortages and the need to perform surgery in extreme temperatures. As such, methods for the sanitization of medical tools are sought and efficacy of existing materiel sourced to austere medical facilities should be examined for this purpose. This study tested the efficacy of commercially available, FDA-approved wound cleansers for alternative use as a potential sanitizer of stainless-steel medical devices and instruments found at improvised medical facilities. Escherichia coli and Staphylococcus aureus cultures were inoculated onto sterile stainless-steel carriers. After cleanser treatment, samples were held for 2 h, 24 h, or 7 days to represent different turn-around times between uses at ambient (25°C), cold (-20°C) and hot (50°C) temperatures. Additional ex vivo challenges were performed using slurry harvested from porcine cecum. Colony-forming units and log reduction were calculated. Significance was determined using one-way ANOVA and multiple comparisons between treatment groups were calculated using Tukey's multiple comparison test. All wound cleansers demonstrated statistically significant bactericidal activity against lab bacteria and ex vivo cecal slurry. E. coli and S. aureus resulted in approximately a 5-6 log reduction on average, resulting in no growth after treatment for all cleaners at 2 and 24 h. Similarly, 7-day post exposure results in a 6-log reduction after treatment for all groups at 25°C and -25°C. While treatment of ex vivo samples did not result in total kill, significant reductions in bacterial load were observed in all groups. Wound cleansers cleared for use in surgical settings demonstrated antimicrobial effects against bacteria deposited on metal surfaces. These cleansers decreased bacterial viability when challenged against extreme temperatures and few bacteria were harvested from treated surfaces even after 7 days. FDA-approved wound cleaners show promise as a potential sanitizer in resource limited environments.

Continued Development and Testing of a Novel Steerable Chest Tube, Extendable Infusion Cannula, and Portable Suction-Infusion Pump for Use in Austere and Transport Environments to Prevent Retained Hemothorax.

With blunt and penetrating trauma to the chest, warfighters frequently suffer from hemothorax. Optimal management requires the placement of a chest tube to evacuate the blood. Malposition of the tube may be a causative factor of inadequate drainage (retained hemothorax). As a potential solution, we developed a previously reported steerable chest tube allowing accurate placement into a desired location to enhance effectiveness. To provide assisted aspiration, we developed a portable, battery-operated suction device capable of simultaneous or sequential infusion. This report details the ongoing progress of this project. Updated steerable tube and pump prototypes were designed and produced. The tubes were tested for feasibility in two pigs and one cadaver by fluoroscopically comparing tip positions after insertion by a number of providers. Measured drainage volumes comparing standard vs. steerable tubes after pleural infusion of 1,000 mL of saline in two pigs were compared. Testing of the pump focused on the accuracy of suction and volume functions. The steerable tube prototype consists of sequentially bonded segments of differing flexibility and an ergonomic tensioning handle. The portable suction pump accurately provides up to 80 cmH2O of suction, an infusion capability of up to 10 mL/min, and a 950 mL removable reservoir canister. After minimal training, providers easily and repeatedly placed the tip of the steerable tube in the lateral diaphragmatic sulcus in animals and cadavers. Arc was limited to the distal segment. Compared to a standard tube, the steerable tube placed along the diaphragm improved pleural fluid drainage volumes by 17%, although this did not reach statistical significance in six trials. These new prototypes represent substantial improvements and were performed according to expectations. We believe that this steerable chest tube and portable suction-infusion pump can be effectively used for warfighters with chest injuries in austere environments.

Innovative Curriculum to Train Medical Students on Lateral Canthotomy and Cantholysis.

Orbital compartment syndrome (OCS) is an ocular emergency requiring prompt decompression with a lateral canthotomy and cantholysis (LCC) within 2 hours. This study evaluates the feasibility and effectiveness of a standardized LCC curriculum to train medical students to identify and treat OCS. This was a prospective, non-randomized, non-comparative cohort study of 39 novice first-year medical students with no prior LCC training who underwent a standardized LCC curriculum incorporating both didactic and hands-on procedural training. Didactic knowledge of orbital anatomy and OCS was evaluated with written pre- and post-knowledge testing. Expert performance criteria were determined by expert consensus based on the performance of three oculoplastic surgeons and were defined as correctly performing all 12 critical checklist steps of an LCC within 3 minutes twice consecutively on a Sonalyst LCC training system eye model. Utilizing the principles of mastery learning, participants learned how to perform an LCC in a classroom environment and were evaluated on a final test of proficiency in a training lane designed to simulate an austere military environment. Participants required a median of 3.0 practice iterations to achieve expert performance in the classroom environment. During the testing phase, all participants correctly identified the eye with OCS, and 77% (n = 30) of learners successfully performed an LCC at the expert level within their first attempt. The median completion time of those who passed on their first testing was 130 seconds. The mean LCC knowledge test scores significantly improved from 48.7% to 71.2% (P < .001). This study successfully developed a standardized LCC curriculum utilizing the principles of hands-on mastery learning to train novice learners to perform an LCC efficiently and effectively.

Tidal and Wave Renewable Energy: In Support of Marines during Expeditionary Advanced Base Operations

This study proposes an improved method of military logistics focused on tidal and wave renewable energy that reduces vulnerabilities tied to required resupplies and extends U.S. Marine Corps endurance in forward, austere expeditionary advanced base operations environments, ultimately creating options to persist within an adversary’s weapons engagement zone. Currently, one major problem surrounding traditional military operations is an overreliance on fuel, which results in increased consumption and financial costs, as well as the risk to force and risk to mission associated with logistical resupplies. In this article, both descriptive and explanatory qualitative research methods facilitate an understanding of military logistical problems and then explore current commercial logistical solutions for potential future military applications. The results highlight the ability of tidal energy converters to provide efficient and cost-saving renewable energy solutions at military bases and stations. Further results emphasize wave energy converters as viable renewable energy solutions to support the Marine littoral regiment with 2.8 megawatts of power (reducing consumption by 30 percent), combat operations centers, and light and ultralight hybrid tactical vehicles by cutting the tether of required resupplies, limiting fuel costs, and ultimately reducing the risk to force and risk to mission.

Infectious etiologies among post-donation deferrals in a military blood donation center.

The burden of transfusion-transmitted infections among blood recipients remains low due to extensive pre- and post-donation screening. However, the military has the unique challenge of providing blood in austere environments with limited testing capabilities. This study evaluates the infectious etiologies of deferred blood donors at a large military blood donation center. All blood donors at the Armed Service Blood Bank Center, San Antonio, between 2017 and 2022 with positive post-donation screening for hepatitis C (HCV), hepatitis B (HBV), human immunodeficiency virus (HIV), human T-lymphotropic virus (HTLV-I/II), Zika (2018-2021), West Nile virus, Trypanosoma cruzi, Treponema pallidum, or Babesia microti (2020-2022) were evaluated. Donors were deferred based on Food and Drug Administration (FDA) guidance. Two-hundred and thirteen (213) donors met FDA criteria for deferral. T. pallidum (n = 45, 50.3 per 100,000), HCV (n = 34, 38.0 per 100,000), and HBV (n = 19, 21.2 per 100,000) were the most common pathogens among those with both positive screening and confirmatory testing. The majority of HIV (95%), Chagas (78%), HTLV-I/II (50%) deferrals were due to indeterminate confirmatory tests following initial positive screens. The majority of deferrals for HBV were for a second occurrence of a positive screen despite negative confirmatory testing. The rates of post-donation deferral for transfusion-transmissible infections were low in this military cohort. Our findings suggest that donor testing in deployed service members should focus on HBV, HCV, and T. pallidum and highlight the need for better diagnostics for HIV, Chagas, and HTLV-I/II.

Disruption ofBiofilm by Bacteriophages inClinically Relevant Settings.

Antibiotic-resistant bacteria are a growing threat to civilian and military health today. Although infections were once easily treatable by antibiotics and wound cleaning, the frequent mutation of bacteria has created strains impermeable to antibiotics and physical attack. Bacteria further their pathogenicity because of their ability to form biofilms on wounds, medical devices, and implant surfaces. Methods for treating biofilms in clinical settings are limited, and when formed by antibiotic-resistant bacteria, can generate chronic infections that are recalcitrant to available therapies. Bacteriophages are natural viral predators of bacteria, and their ability to rapidly destroy their host has led to increased attention in potential phage therapy applications. The present article sought to address a knowledge gap in the available literature pertaining to the usage of bacteriophage in clinically relevant settings and the resolution of infections particular to military concerns. PRISMA guidelines were followed for a systematic review of available literature that met the criteria for analysis and inclusion. The research completed for this review article originated from the U.S. Military Academy's library "Scout" search engine, which complies results from 254 available databases (including PubMed, Google Scholar, and SciFinder). The search criteria included original studies that employed bacteriophage use against biofilms, as well as successful phage therapy strategies for combating chronic bacterial infections. We specifically explored the use of bacteriophage against antibiotic- and treatment-resistant bacteria. A total of 80 studies were identified that met the inclusion criteria following PRISMA guidelines. The application of bacteriophage has been demonstrated to robustly disrupt biofilm growth in wounds and on implant surfaces. When traditional therapies have failed to disrupt biofilms and chronic infections, a combination of these treatments with phage has proven to be effective, often leading to complete wound healing without reinfection. This review article examines the available literature where bacteriophages have been utilized to treat biofilms in clinically relevant settings. Specific attention is paid to biofilms on implant medical devices, biofilms formed on wounds, and clinical outcomes, where phage treatment has been efficacious. In addition to the clinical benefit of phage therapies, the military relevance and treatment of combat-related infections is also examined. Phages offer the ability to expand available treatment options in austere environments with relatively low cost and effort, allowing the impacted warfighter to return to duty quicker and healthier.

Nutrition Considerations for Burn Patients: Optimizing Recovery and Healing

The hypermetabolic and hypercatabolic responses to severe burns put nutrition support at the forefront of treatments. When left untreated, severe weight loss, increased infection, and wound healing failure can occur. Enteral nutrition is the primary method of nutrition support in such patients. Meeting caloric needs and a positive nitrogen balance are short-term goals of nutrition support, with long-term goals of minimizing lean body mass loss and maximizing wound healing. High-carbohydrate and low-fat nutrition received evidence from randomized controlled trials of aiding in decreasing pneumonia rates and was found to promote positive nitrogen balance, which lipids do not do. We go through the macronutrient and micronutrient needs of the burn patient as well as techniques for meeting these needs in the modern intensive care unit, with some discussion of alterations in these techniques that are required in the austere environment.

Evaluation ofTopical Off-the-Shelf Therapies to Reduce the Need to Evacuate Battlefield-Injured Warfighters.

Immediate evacuation of burn casualties can be challenging in austere environments, and it is predicted to be even more difficult in future multi-domain battlespaces against near-peer foes. Therefore, a need exists to treat burn wounds at the point of injury to protect the exposed injury for an extended period. In this study, we compare two commercially available FDA-approved therapies to the current gold standard of care (GSOC), excisional debridement followed by the application of split-thickness skin graft, and the standard for prolonged field care, silver sulfadiazine (SSD) cream. The shelf-stable therapies evaluated were irradiated human skin (IHS) allograft and polylactic acid (PLA). Our objective was to study whether they have the potential capability to reduce the need for evacuation to a burn center for surgical intervention so that the combat power can be preserved in the field. Sixteen burns (50 cm2) were created on the dorsum of four anesthetized swine. All materials were sterile, but a sterile field was not utilized in order to simulate the prolonged field care setting. The wounds were then treated with PLA, IHS, and SSD cream, and the remaining wounds (designated GSOC) were also treated with SSD cream. On post-operative day (POD) 3, sterile surgical debridement and skin grafting (1:4) were performed on the GSOC wounds. Burn healing was followed for either PODs 10, 14, 21, or 28, wherein one animal was humanely euthanized at each time point; each represented a time point of the healing process. A full-thickness excisional biopsy was taken from each wound immediately after euthanasia to give a cross-section view of the wound edge to edge. Wound healing was determined by the histological analysis of wound re-epithelialization, epidermal thickness, rete ridges, and scar elevation index and macroscopically using noninvasive imaging systems. The PLA and IHS treatments did not need to be reapplied to the wounds during the course of the experiment, unlike SSD, which was reapplied at each assessment time point. In terms of re-epithelialization, on POD 10, IHS and SSD were similar to the GSOC; on POD 14, all treatments were similar; on POD 21, PLA and IHS were similar to SSD; finally, on POD 28, re-epithelialization was similar in all groups. On POD 28, scar elevation index and rete ridges/mm were similar to all groups, and epidermal and dermal thickness for PLA and IHS were similar to GSOC. This preclinical study demonstrated that the use of the PLA and the IHS dressings resulted in similar outcomes to the GSOC-treated burns in several key metrics of wound healing. These therapies represent a potentially useful tool in current and future battlespaces, where surgical intervention is not possible. The products are lightweight and, more importantly, stable at room temperature for their entire shelf lives. This would allow for easy storage and transport by medical practitioners in the field.

In Flight Preterm Birth is There a Doctor on Board?

This case report a case of in-flight preterm birth. In-flight medical emergencies can occur when a passenger or crew member becomes ill or injured during a flight. Preterm birth, defined as birth before 37 completed weeks of gestation, is a significant public health concern worldwide due to its association with increased neonatal morbidity and mortality. Although in-flight medical emergencies and onboard deaths are uncommon, they pose a significant challenge to the airline industry. The medically austere environment, coupled with limitations on prudent practice and associated liabilities, requires physicians and other healthcare providers traveling on flights to be aware of these factors.

Findings on High Resolution Computed Tomography in Symptomatic Veterans with Deployment-Related Lung Disease.

Military deployment to dusty, austere environments in Southwest Asia and Afghanistan is associated with symptomatic airways diseases including asthma and bronchiolitis. The utility of chest high-resolution computed tomographic (HRCT) imaging in lung disease diagnosis in this population is poorly understood. We investigated visual assessment of HRCT for identifying deployment-related lung disease compared with healthy controls. Chest HRCT images from 46 healthy controls and 45 symptomatic deployed military personnel with clinically confirmed asthma and/or biopsy-confirmed distal lung disease were scored by 3 independent thoracic radiologists. We compared demographic and clinical characteristics and frequency of imaging findings between deployers and controls, and between deployers with asthma and those with biopsy-confirmed distal lung disease, using χ2, Fisher exact or t tests, and logistic regression where appropriate. We also analyzed inter-rater agreement for imaging findings. Expiratory air trapping was the only chest CT imaging finding that was significantly more frequent in deployers compared with controls. None of the 24 deployers with biopsy-confirmed bronchiolitis and/or granulomatous pneumonitis had HRCT findings of inspiratory mosaic attenuation or centrilobular nodularity. Only 2 of 21 with biopsy-proven emphysema had emphysema on HRCT. Compared with surgical lung biopsy, visual assessment of HRCT showed few abnormalities in this small cohort of previously deployed symptomatic veterans with normal or near-normal spirometry.

The Basic and Clinical Science of Wounds in the Austere Environment

Surgery in developing countries is challenging on many levels. U.S. organizations sponsor approximately 200,000 surgeries performed abroad every year (Miclau et al. 2021a). These altruistic surgeons and physicians– despite their good intentions—may not be equipped with the specific surgical and communication skills necessary for a successful surgery in an austere environment. Surgical skill set, nutrition, facilities, and sociology all play a role in successful surgical outcomes. A thorough understanding of the basic science and clinical science of wounds in the austere environment is imperative for physicians and surgeons providing care in developing nations. Basic science research, in regards to nutrition, parasites; skin, dermal, and bone physiology; as well as microbiome interaction with these structures, can help optimize surgical outcome and reduce adverse events such as infection. Clinical science research and the development of algorithms for surgery in the austere environment can also help improve surgical outcomes and mitigate these adverse events.

Practice Preferences using Resuscitative Endovascular Balloon Occlusion of the Aorta for Traumatic Injury Before and After the 2017 EndoVascular and Hybrid Trauma and Bleeding Management Symposium

Background: Resuscitative endovascular balloon occlusion of the aorta (REBOA) is a technique to aid in resuscitative eff orts for hemorrhagic shock. The use of REBOA is not yet commonplace and there is little understanding of real-world practice patterns. The Endovascular and Hybrid Trauma and Bleeding Management Symposium is a large international conference specifically developed to discuss multidisciplinary, endovascular and hybrid approaches to hemorrhage management. We sought to evaluate provider opinions and practice patterns using REBOA for traumatic vascular injury before and after attending this conference. Methods: A detailed survey was completed by a variety of providers before and after the conference. The survey was composed of demographic information, and focused on practice patterns and opinions regarding the implementation of REBOA.Results: We received 186 survey responses (99 pre, 87 post). There was increased perception of feasibility for REBOA in all settings, with the largest increase for pre-hospital and austere military environments (53.5% pre, 67.8% post and 59.6% pre, 73.6% post respectively). While there was no consensus on tolerable occlusion times and indications for utilization, most participants felt that partial REBOA was the most viable technique for prolonging the benefi ts of REBOA, and more participants came to this conclusion after attending the conference (62.2% pre, 81.6% post, p = 0.006). Conclusions: REBOA is an exciting and important advancement in the management of life threatening hemorrhage; however, its implementation has not been codifi ed and there is much variation in practitioners’ understanding of its use. Continued investigation is needed to determine the appropriate indications, methods, and practical limitations of REBOA as a new hemorrhage management paradigm.

Manual vs Mechanical Cardiopulmonary Resuscitation for Out-of-Hospital Cardiac Arrest on a Ski Slope: A Pilot Study.

The quality of cardiopulmonary resuscitation (CPR) is critical in increasing the probability of survival with a good neurologic outcome after out-of-hospital cardiac arrest. In an austere environment with a potentially salvageable patient, bystanders or first responders may need to provide chest compressions for a prolonged duration or during physically challenging transportation scenarios. Consequently, they may be at risk of fatigue or injury, and chest compression quality may deteriorate. The study sought to assess whether or not access to and utilization of a mechanical compression device (Lund University Cardiopulmonary Assist System) was feasible and not inferior to manual compressions while extricating and transporting a patient from a ski slope. Variable 3-person ski patrol teams responded to a simulated patient with out-of-hospital cardiac arrest in a nonshockable rhythm. Using a mannequin and CPR quality monitor, performance during manual CPR was compared with that of a mechanical compression device. This is a prospective, crossover analysis of CPR quality during extrication from a ski slope. Across 8 total runs, chest compression fraction, which is the proportion of time without spontaneous circulation during which compressions occurred, and high-quality CPR, as measured by appropriate rate and depth, were compared between the 2 groups. Extrication times between the 2 groups were also measured. There was no difference in compression fraction between the manual (91.4%; 95% CI [86.8-96.1]) and mechanical arms (92.8%; 95% CI [88.8-96.8]) (P=0.67). There was an increase in the time performing high-quality CPR in the mechanical group (58.5%; 95% CI [45.8-71.2]) vs that in the manual group (25.6%; 95% CI [13.5-37.8]) (P<0.001). There was a statistically significant difference in the extrication times between the 2 groups, 7.6 ± 0.5 min in the manual group vs 8.6 ± 0.4 min in the mechanical group (P=0.014). Mechanical CPR devices are noninferior for use in ski areas during initial resuscitation and transportation. Compared with manual CPR, mechanical CPR would likely improve the fraction of time performing high-quality CPR.

Development of a graphical user interface for automatic separation of human voice from Doppler ultrasound audio in diving experiments.

Doppler ultrasound (DU) is used in decompression research to detect venous gas emboli in the precordium or subclavian vein, as a marker of decompression stress. This is of relevance to scuba divers, compressed air workers and astronauts to prevent decompression sickness (DCS) that can be caused by these bubbles upon or after a sudden reduction in ambient pressure. Doppler ultrasound data is graded by expert raters on the Kisman-Masurel or Spencer scales that are associated to DCS risk. Meta-analyses, as well as efforts to computer-automate DU grading, both necessitate access to large databases of well-curated and graded data. Leveraging previously collected data is especially important due to the difficulty of repeating large-scale extreme military pressure exposures that were conducted in the 70-90s in austere environments. Historically, DU data (Non-speech) were often captured on cassettes in one-channel audio with superimposed human speech describing the experiment (Speech). Digitizing and separating these audio files is currently a lengthy, manual task. In this paper, we develop a graphical user interface (GUI) to perform automatic speech recognition and aid in Non-speech and Speech separation. This constitutes the first study incorporating speech processing technology in the field of diving research. If successful, it has the potential to significantly accelerate the reuse of previously-acquired datasets. The recognition task incorporates the Google speech recognizer to detect the presence of human voice activity together with corresponding timestamps. The detected human speech is then separated from the audio Doppler ultrasound within the developed GUI. Several experiments were conducted on recently digitized audio Doppler recordings to corroborate the effectiveness of the developed GUI in recognition and separations tasks, and these are compared to manual labels for Speech timestamps. The following metrics are used to evaluate performance: the average absolute differences between the reference and detected Speech starting points, as well as the percentage of detected Speech over the total duration of the reference Speech. Results have shown the efficacy of the developed GUI in Speech/Non-speech component separation.

Mechanical assessment of proprietary and improvised pelvic binders for use in the prehospital environment

IntroductionPelvic fractures often result from high-energy trauma and are associated with a 10% mortality rate and significant morbidity. Pelvic binders are applied in suspected pelvic injury to stabilise fractured bone,...