We evaluated pressures and tightening-system use of 3.8cm-wide, self-securing-strap/redirect-and-tightening-system X8T-T2G tourniquets (X8Ts). Applied left/right, mid-arm and mid-thigh, 40 recipients, first completion one-click-past arterial occlusion, release 100s later. Compared to concurrent study: four 3.8cm-wide, windlass-rod-tightening-system tourniquets (n=30 each). All X8T reached occlusion and completion without securing struggles. Maintaining occlusion till release, 3 arms/25 thighs required additional click once, 2/2 required twice, and 1 thigh required thrice. Nineteen arms large enough for X8T pressure monitoring: occlusion median 298mmHg (minimum 188, interquartile range 262, 322, maximum 335), first completion 338mmHg (219, 310, 372, 391), pre-release 304mmHg (172, 270, 323, 342). Thigh pressures: occlusion 359mmHg (273, 334, 388, 478), first completion 393mmHg (308, 366, 426, 489), pre-release 368mmHg (289, 339, 390, 462); each< respective windlass-rod tourniquet pressures (every P<.030). Arm clicks: occlusion 5 (0, 4, 7, 10), first completion 6 (1, 5, 8, 11), pre-release 7 (1, 5, 8, 11); first completion and pre-release tightening-system rotation<windlass-rod tourniquets (every P<.0001, 10 clicks=180°). Thigh clicks: occlusion 13 (6, 10, 16, 39), first completion 14 (7, 11, 17, 40), pre-release 15 (7, 12, 18, 41); first completion and pre-release tightening-system rotation<windlass-rod tourniquets (one pre-release P=.072, all other P<.005). Clicks after first completion took 2s (1, 2, 3, 4); faster than 66 additional uses of windlass-rod tightening systems (medians 10-18s, every P<.0001). X8Ts were arterially occlusive with simple, self-securing, tightening-system advances. Versus windlass-rod systems, first completion and pre-release pressures and total tightening-system rotation were lower, and completion of tightening-system use after first completion was faster.

Hyperbaric oxygen (HBO2) therapy is essential for the treatment of diving injuries in the field, but typically requires larger recompression chambers with limited porta-bility. The Emergency evacuation hyperbaric stretcher (EEHS) offers a portable solution for prehospital HBO2, particularly in remote or austere environments. However, it's compatibility with smaller evacuation aircraft remains uncertain. A commercially available EEHS (Hyperlite 1) was tested for fit and operational computability in both a U.S. Coast Guard Air-bus MH-65 "Dolphin" and an Airbus H145 helicopter with a configuration typical of civilian air ambulances. The EEHS could not be fully accommodated in the MH-65 with-out the side doors remaining open and obstructing the rescue swimmer's seat. These limitations may pose challenges to the safe transport of an EEHS during standard operational scenar-ios, necessitating additional logistical support and introducing potential safety risks. The EEHS did fit within the H145, op-timally without a large transport cot in place. In both cases, the required tie-down straps were unavailable. Un anticipated airframe limitations may impede the timely evacuation of a diving casualty to advanced care. These find-ings highlight the importance of planning for the use of the EEHS including careful consideration of the potential aircraft platforms available. Further research is recommended to assess newer EEHS models and to improve aircrew and clinician fa-miliarity with EEHS transportation requirements.

Hypothermia is a major driver of trauma-induced coagulopathy on the battlefield. Several portable blood warmers have been developed for use in forward-deployed prehospital environments; however, end-user preferences for device use have not previously been investigated. A convenience sample of Naval Special Warfare (NSW) Corpsmen (HMs, n=35) were surveyed regarding their perceived usability of five blood warmer devices: the QinFlow®, M Warmer, Buddy Lite®, Thermal Angel™, and the North American Rescue (NAR) Quantum®. The Likert-based survey was built around evaluating three domains: ease of use, device ruggedness, and perceived device efficacy. Responses were quantified and compared using the Kruskal-Wallis test and the chi-square test, as appropriate. Statistical significance was defined as P<.05. Qualitative responses were summarized into major themes. The M Warmer received the highest overall scores in all three domains with statistically significant differences identified across most comparisons to other warmers. Qualitative analysis reinforced these findings, emphasizing the importance of compactness, intuitive deployment, and device reliability in austere environments. The M Warmer was the most frequently preferred device (45%, P=.0067), with users citing portability, rapid setup, and compatibility with existing gear as key advantages. In this cohort of NSW HMs, user-centered evaluation of field blood warmers identified the M Warmer as the most operationally favorable device. Preferences were shaped not only by perceived effectiveness but by factors directly relevant to forward-deployed settings: portability, intuitive operation, and logistical simplicity. These findings underscore the importance of integrating end-user feedback into medical equipment acquisition.

The Team Awareness Kit (TAK, also called Tactical Assault Kit) has significant potential to improve medical regulation in combat operations. TAK is a software package able to be used by individuals in the field which provides geospatial infrastructure and military situational awareness. While it is widely used by non-medical military units, most medical forces have not yet integrated it, particularly for casualty tracking. TAK offers better emission control and detailed medical data than traditional communication systems. Two examples of its use described in this report are from exercises with III Marine Expeditionary Force (MEF) in the Indo-Pacific. Key lessons included: 1) full integration of TAK into Health Services Support (HSS) for improved patient outcomes, 2) managing information overload through standardized workflows, and 3) clear medical control (MEDCON) to optimize casualty care. Recommendations include establishing a communications plan, regulating communication between care echelons, and standardizing TAK workflows for casualty care and medical logistics. TAK proved to be a low-cost, effective tool for medical command and control, and should be further considered for adoption across Joint and Partner Forces.

Operational experience from the Russo-Ukrainian War revealed frequent use of tourniquets that were not medically indicated and an increase in ischemic complications from prolonged tourniquet application as a consequence of extended evacuation times. In response to this, the Committee on Tactical Combat Casualty Care (CoTCCC) convened a working group to evaluate whether tourniquet reassessment and conversion practices should extend to the All Service Member (ASM) level. With input from NATO and partner nations, the Working Group developed a standardized, time-based algorithm that provides plain language guidance for reassessment, repositioning, and conversion. The proposed change replaces the term replacement with repositioning, affirms a reassessment window within 2 hours for nonmedical personnel, and limits conversion beyond 2 hours to medical personnel. These updates will expand lifesaving capability to nonmedical responders, reduce preventable morbidity and mortality from tourniquet use, and align TCCC principles with current operational realities.

The Blast Exposure Threshold Survey (BETS) is a self-report questionnaire assessing lifetime generalized blast exposure value (GBEV). This study examined GBEV convergent validity and GBEV and BETS item-by-item test-retest reliability. In this prospective-cohort study, Army Special Operations Forces (ARSOF) trainers and trainees completed the BETS and a demographic intake form one week before Special Forces Advanced Urban Combat (SFAUC) training. BETS was also administered 1 and 8 weeks post-training. Spearman's rho correlations assessed convergent validity from pre-SFAUC time points. A two-way mixed effect, consistency, single rater intraclass correlation coefficient (ICC3,1 [95%CI]) and percent agreement analyzed test-retest reliability for post-SFAUC time points. Forty-one participants (17.1% trainers; mean age: 32.8 [SD 5.7] y), and 13 participants (7.7% trainers; mean age: 33.2 [SD 5.6] y; 49.7 [SD 6.5] days between test-retest) were included in convergent validity and test-retest analyses, respectively. GBEV displayed moderate convergent validity with all proxy measures of blast exposure (rho-range=0.595-0.672, P<.001 all). GBEV displayed moderate test-retest reliability (ICC3,1=0.576 [95% CI 0.160-0.818]). Individual weapon categories were poor-moderate (ICC3,1-range=0.070-0.766). Items within each section displayed poor-excellent test-retest reliability (ICC3,1range=-0.145-0.843). The difference and average from both post-SFAUC timepoint were strongly correlated indicating worse recall with higher GBEV (n=13, rho=0.907, P<.001). GBEV has strong convergent validity but poor-moderate test-retest reliability. Caution should be used when interpreting BETS results, especially in populations experiencing excessive blast exposures. However, our small sample size limits the interpretability of the results.

Artificial intelligence (AI) has the potential to address training limitations and inter-operator variability that constrain the use of lung ultrasound (LUS) in austere and prehospital settings. This pilot study evaluated whether AI-based decision support could improve the diagnostic accuracy and confidence of United States Marine Corps Corpsmen in identifying absent lung sliding, a key indicator of pneumothorax, during LUS interpretation. This pilot-prospective multi-reader, multi-case study involved five military medics, all novices in point-of-care ultrasound, each interpreting 50 de-identified LUS video clips twice, once without AI assistance (control) and once with AI assistance (ATLAS, Deep Breathe Inc., London, Canada), in randomized order with at least a 2-hour washout between sessions. Expert consensus served as a reference standard. Diagnostic performance was assessed using area under the receiver operating characteristic curve (AUROC), sensitivity, specificity, and accuracy. Differences were analyzed using the Random-Reader Random-Case method. Per-clip reader confidence ratings were compared using the Stuart-Maxwell test. AI assistance significantly improved diagnostic performance across all measured outcomes. The mean AUROC increased from 0.72 (SD 0.16) without AI to 0.93 (SD 0.04) with AI (P=.03). Sensitivity rose from 0.63 (SD 0.14) to 0.90 (SD 0.09), specificity from 0.70 (SD 0.15) to 0.86 (SD 0.10), and overall accuracy from 0.67 (SD 0.10) to 0.88 (0.06) (McNemar's test, P<.001). Reader confidence also improved, with high-confidence ratings nearly doubling from 20% to 37%, and low-confidence ratings decreasing from 38% to 33%. These distributional changes were statistically significant (Stuart-Maxwell χ², P<.001). AI support markedly improved the diagnostic accuracy and confidence of novice LUS interpretation for detecting absent lung sliding. These findings suggest that real-time AI-based decision support may help improve access to high-quality LUS in military and other resource-limited care settings.

Emerging technologies for monitoring vital signs are increas-ingly being adapted for surveillance purposes. As these tools grow more sophisticated, traditional countermeasures em-ployed by Special Operations Forces (SOF) may no longer be sufficient. This brief highlights examples of biological surveil-lance technologies and proposes a holistic response by con-ceptualizing the management of biological signatures during operations as biological Operational Security (bio-OPSEC). SOF medics-by virtue of their tactical perceptiveness and med-ical acumen-can play a vital role in bio-OPSEC, enhancing awareness and mitigating their team's vulnerabilities. Drawing on insights from bio-sensing technologies and security studies this in brief article introduces actionable approaches for im-plementing bio-OPSEC.

Night vision goggles (NVG) grant warfighters a tactical advantage in low-light environments. However, NVG use can negatively affect visual acuity, depth perception, and color discrimination, which impacts warfighter safety and operational performance. Therefore, the purpose of this study was to examine the biomechanical effects in the walking phase of an obstacle clearance course and prefrontal cortex (PFC) regional oxygen saturation (rScO2) during embedded marksmanship and cognitive tasks performed with and without NVGs. Twelve participants (21 [SD 1] years) completed an obstacle avoidance course with and without NVGs, which included pistol marksmanship assessments, cognitive assessments, and ground obstacles. Gait pattern, performance tasks, and PFC activity were recorded. Marksmanship performance decreased by 58.2% (P<.01), but cognitive performance was not impacted with NVG use (P=.676). Toe clearance increased by 32.2% (P<.01), toe velocity decreased by 20.5% (P<.01), and ankle dorsiflexion increased by 24.0% (P=.02) with NVG. Significant reductions in rScO2 during Marksmanship 2 (P<.01) and Cognitive Assessment Task 1 (P=.01) and 2 (P=.01) were observed. Performance decrements with NVG use are hypothesized to be primarily due to altered vision perception and increased metabolic demand affecting marksmanship performance and gait patterns. NVG training may minimize the risk of musculoskeletal injuries and improve operational performance.