Military Medicine最新文献

Introduction: Basic military training is crucial for preparing civilians for military life. This period prepares them with physical and cognitive skills required for military service. However, basic military training is marked by a high incidence of musculoskeletal injuries. In addition, female sex has been identified as a risk factor in military training courses, contributing to higher medical treatment costs and reduced operational readiness.

Objective: To investigate the incidence of musculoskeletal symptoms and injuries in male and female recruits during sixteen weeks of Brazilian Marine Basic Military Training, as well as to assess their potential risk factors.

Methods: A total of 626 military recruits were enrolled in the training period. The study was divided into two phases. Firstly, a cross-sectional analysis included body composition assessment and physical fitness tests. Secondly, a retrospective analysis included the application of the Nordic Musculoskeletal Symptoms Questionnaire (NMQ) at the end of the course to assess the musculoskeletal complaints experienced by the recruits. A logistic regression analysis investigated factors associated with injuries, adjusting for physical fitness variables. Data analysis was performed using Jamovi software, with a significance level set at 0.05.

Results: The NMQ revealed that women had a higher risk in the following categories: any symptom, symptoms that resulted in time loss from duties, symptoms that required medical attention, symptoms in the 7 days preceding the baseline evaluation, trunk injuries, upper and lower limbs injuries. However, after adjusting for physical fitness variables, the fitness-related factors associated with the incidence of musculoskeletal symptoms were body fat percentage and running performance only for symptoms that led to medical consultation or duty restriction. Sex was associated only with the week in which the NMQ was administered. The activities associated with a higher risk of injuries in women were drill and ceremonies, load carriage marching, and obstacle courses.

Conclusions: The present study identified that sex, body fat percentage, and running performance were risk factors for musculoskeletal symptoms in recruits. Additionally, physical training, loaded marching, and running were the activities most associated with injuries during the training course.

Introduction: Aerobic exercise and cold exposure modulate lipid mediator production, which may optimize physiological resilience. The Yukon Arctic Ultra (YAU), a 692-km self-provisioned multiday endurance event, offers a unique opportunity to examine lipidomic adaptations to nutrients and environmental and physical stress. This study aimed to identify lipid mediators responsive in YAU athletes compared to control participants.

Methods: Nine athletes and six controls were recruited from the 2017 and 2019 YAU events. Targeted liquid chromatography-tandem mass spectrometry/mass spectrometry-based signaling lipidomic analysis was conducted on serum samples collected from participants at pre-event, during the event, and post-event time points.

Results: Athletes and controls did not differ significantly in age, body mass index (BMI), fat mass index (FMI), or fat-free mass index. During the event, athletes exhibited significant reductions in BMI, fat mass, and FMI, whereas no changes were observed in controls. Athletes showed higher baseline levels of anti-inflammatory oxylipins, including resolvin D2 and lipoxin A4 (LXA4), and lower levels of the pro-inflammatory leukotriene E4 compared to controls. Linoleic acid- and α-linolenic acid-derived oxylipins were also elevated in athletes. Notably, these anti-inflammatory lipids remained elevated throughout the event. Certain hydroxy-eicosapentaenoic acids demonstrated a declining trend during the event in athletes.

Discussion: YAU athletes exhibit a distinct lipidomic signature marked by persistently elevated anti-inflammatory oxylipins, likely reflecting a complex interplay between adipose tissue and skeletal muscle. Overall, the oxylipin shifts point to anti-inflammatory and thermogenic adaptations that support physiological resilience during physical, nutrient, and environmental stress in austere circumstances.

Introduction: Approximately 50% of the United States (U.S.) adult population uses at least one dietary supplement (DS). Higher DS use is reported among occupations with high physical fitness demands. As of 2021, roughly 75% of U.S. military service members (SMs) used at least one DS weekly. The primary objective of this quality improvement project was to characterize the DS environment on two U.S. military installations.

Materials and methods: Fort Drum in the United States and Camp Buehring in Kuwait were surveyed from March to August 2024. A team of 12 health professionals (Registered Dietitian Nutritionists, Health Educators, and Certified Strength and Conditioning Specialists) analyzed 1,209 unique DS sold on Fort Drum and/or Camp Buehring. By analyzing the DS labels, our team assessed DS for dosage of vitamins and minerals, caffeine content, presence of stimulants and prohibited substances, as well as for the Operation Supplement Safety (OPSS)-vetted third-party certification organization seals.

Results: Of the 1,209 unique DS examined, 250 (21%) contained a proprietary blend, matrix, or complex. Additionally, 461 (38%) had more than 200% of the established Daily Value for at least one vitamin or mineral, 63 (5%) contained more than 200 mg of caffeine per serving, and 87 (7%) were found to contain multiple stimulants. Only 120 (10%) of the DS were certified by an OPSS-vetted third-party certifying agency. No prohibited substances were identified on the labels of the evaluated DS.

Conclusions: Given the significant risk to medical readiness, it behooves the Department of Defense (DoD) to more closely monitor DS sold on installations. As the lead organization for supplement education and mandatory safety training, OPSS should play a central role in reassessing the vetting process of DS sold on military installations. Integrating OPSS into this process would help mitigate the risk of SMs inadvertently consuming prohibited substances.

Introduction: Rapid, intravenous (IV) infusion is critical for resuscitation in emergency medicine. Needleless connectors improve safety by reducing the risk of bloodstream infection transmission and air embolism; however, needleless connectors also significantly limit flow rates. Although prior studies demonstrated that 3-way and 4-way "high-flow" stopcocks have flow rates noninferior to uninterrupted catheter tubing, the performance of 1- and 2-way high-flow stopcocks remains poorly understood. This study evaluated flow rates across various catheter connection adjuncts to identify optimal devices for resuscitation efficacy.

Materials and methods: A 500-mL infusion circuit of 0.9% normal saline was tested with needleless connectors, standard and high-flow stopcocks under gravity (0 mm Hg) and pressurized (300 mm Hg) conditions. A 16-gauge IV catheter connected directly to IV tubing served as the control. Fluid volume was measured gravimetrically over 120 seconds, and flow rate was calculated. Each condition was repeated in quadruplicate. Data were analyzed via 2-way analysis of variance and follow-on Tukey's post hoc testing, with multiplicity-adjusted statistical significance defined as P < .05.

Results: The use of needleless connectors significantly decreased flow compared to control in both the gravity cohort (0.95 ± 0.018 mL/second vs. 1.19 ± 0.05 mL/second, P < .0001) and the pressurized cohort (3.10 ± 0.048 mL/second vs. 3.46 ± 0.072 mL/second, P < .0001). The use of high-flow 2-way stopcocks did not significantly reduce flow in either gravity (1.21 ± 0.05 mL/second, P = .932) or pressurized cohorts (3.42 ± 0.048 mL/second, P = .957) compared to control. In addition, the use of high-flow 3-way stopcocks did not significantly reduce flow in gravity (1.240 ± 0.02 mL/second, P = .368) or pressurized cohorts (3.43 ± 0.064 mL/second, P = .986) compared to control.

Conclusion: In an idealized system, the use of high-flow stopcocks allows for an 8%-10% increase in flow rate compared to needleless connectors, correlating to an additional 400 mL of fluid delivered over a 20-minute period. The 2-way high-flow stopcock could provide a significant advantage by delivering increased flow rates while offering a compact design that maintains a low operational footprint. Given the impact of rapid fluid administration in trauma and resuscitation, high-flow stopcocks may enhance emergency care efficiency in austere combat environments.

Introduction: In November 2012, the U.S. Marine Corps announced a policy change to the female Physical Fitness Test (PFT), replacing the flexed arm hang with pull-ups. This change, which became effective on January 1, 2017, aimed to standardize fitness requirements and facilitate gender integration into combat roles. Musculoskeletal injuries (MSKIs) are a leading cause of medical encounters and non-deployability among service members. Upper extremity (UE) injuries are particularly relevant given the physical demands of pull-ups.

Materials and methods: A retrospective open cohort study was conducted using data from the Military Health System Data Repository (MDR) from fiscal years 2010-2023. International Classification of Diseases (ICD)-9 and ICD-10 codes identified UE injuries in female Marines. Single and multigroup interrupted time series analyses were used to assess changes in injury rates surrounding the PFT policy change.

Results: A total of 49,910 female Marines were included in this study, of whom 6,125 (12.3%) had at least one UE MSKI. The overall trend of UE MSKIs decreased both before and after the PFT policy change. The immediate change post-policy showed no significant changes in UE MSKIs at the time of intervention. However, specific groups experienced significant decreases in MSKI rates at the intervention: Marines ages 20-29 years, those of Black race, junior enlisted ranks, and those with overweight body mass index.

Conclusion: The findings highlight positive impacts of the PFT policy change on reducing MSKI rates among specific subgroups of female Marines. These results inform future policy adjustments aimed at mitigating injury risks while promoting operational readiness across diverse demographics.

Introduction: Pseudofolliculitis barbae (PFB) is an inflammatory follicular disorder caused by shaving in individuals who have naturally curly hair. PFB is commonly seen in the United States Military, where Service Members (SM) are required to shave their facial hair to maintain strict grooming standards. Laser hair removal (LHR) is effective at treating PFB and is an accepted alternative to a shaving waiver.

Materials and methods: 50 patients previously treated for PFB with LHR were identified in the electronic medical record system at Walter Reed National Military Medical Center. All 50 participants were active duty of various ranks and branches during their treatment. LHR treatment series were considered complete after 4-6 sessions separated by 4-8 weeks of LHR with either the Nd: YAG or Alexandrite lasers. Time interval for the search was between January 2017 and June 2021. The authors conducted a phone survey in June 2021. Participants were asked various questions to assess the long-term effectiveness of LHR and subsequent hair regrowth after their LHR treatment. Participants' overall satisfaction with LHR as a PFB treatment modality and impact on military service was queried.

Results: Of the 50 participants (74% identified as Black), 88% were satisfied with LHR. Immediately post-treatment, 70% of participants noted ≥ 75% reduction in PFB lesions, allowing 96% of all participants to resume shaving. PFB recurred in 84% of participants, with 56% of these noting recurrence within 6 months. After treatment, 64% of participants reported patchy hair growth, which became more uniform over time. Notably, PFB influenced 24% of participants' decisions to remain in the military.

Conclusions: LHR is an effective management option for PFB, significantly reducing disease burden and enabling shaving in most military patients. However, recurrence is common, often within six months, necessitating maintenance treatments. Patients require thorough counseling on outcomes and expectation management, including the high likelihood of recurrence and the potential for patchy hair growth. Lastly, educating SM about PFB and LHR during recruitment and basic training may help to increase awareness of this condition and treatment options.

Introduction: There is an unmet need to effectively clear bacterial biofilms, which often cause infections with an antibiotic-resistant phenotype. Biofilms pose an especially acute challenge for combat wound care, as these injuries are often characterized by complex tissue damage that complicates current debridement-based treatment protocols. Targeted localized temperature elevation has been shown to be an effective approach to disrupt cellular membranes. Here, the researchers demonstrated the use of near infrared (NIR) irradiation of gold nanomaterials to elicit the conversion of light to heat energy, and thereby disrupt bacterial biofilms, which rendered them susceptible to antibiotics.

Materials and methods: Staphylococcus epidermidis biofilms were established on tissue-culture treated 96-well plates, and incubated with: (1) nothing (control), (2) gold nanorods (Au-NR), (3) Au-NR in conjunction with NIR irradiation, (4) chitosan-coated Au-NR (chitosan-Au-NR), or (5) chitosan-Au-NR in conjunction with NIR irradiation. Following exposure to NIR, biofilms were incubated overnight in tryptic soy broth in the presence of antibiotic linezolid (128 µg/mL) at 37°C. The biofilms then were scraped, resuspended, and plated in order to quantify bacterial recovery under each experimental condition. Crystal violet staining was used to determine any remaining biofilm in each well.

Results: Linezolid, an antibiotic, has been shown to have limited efficacy against S. epidermidis biofilms and its activity was not affected in the presence of Au-NR. Chitosan-Au-NR, with and without NIR irradiation, significantly increased the antibiofilm efficacy of linezolid. Chitosan-Au-NR increased bacterial inactivation by 14-fold, and the combinatorial effect of chitosan-Au-NRs and NIR irradiation was nearly 42-fold (approximately 99% bacterial inactivation). The respective temperatures of wells containing irradiated Au-NR and irradiated chitosan-Au-NR were 46 ± 1°C and 54 ± 2°C, suggesting that significantly more chitosan-Au-NR were bound at the biofilm.

Conclusions: Chitosan-modified Au-NR showed enhanced localized heat following exposure to NIR. This led to an enhancement of antibiofilm antibiotic efficacy, significantly decreasing the remaining number of colony-forming bacteria. It is envisioned that this approach could provide the basis for the development of a more effective antibiofilm therapeutic strategy, especially for treating wound infections.

Introduction: High dropout rates during the selection of Special Operations Forces (SOF) are well-documented and often linked to inadequate physical preparedness and subsequent injuries. Training recommendations in a preparatory selection phase may offer a strategy to reduce dropout.

Objective: To assess whether fitness-related dropout was reduced in a study population of SOF candidates receiving training recommendations after fitness assessment, compared to historical attrition rates.

Methods: Using a prospective observational design, male candidates across Swiss Armed Forces and police SOF units received individualized training recommendations in the preparation phase of the main selection period. Dropout due to inadequate physical preparedness for the demands of SOF selection and basic training was tracked through all selection stages. A Bayesian analysis compared observed fitness-related dropout rates with a historical control group using a Meta-Analytic Predictive approach.

Results: Fitness-related dropout occurred in 29% of participants (40 of 137), compared to a historical average of 42%, corresponding to a relative reduction of over 30%. The posterior probability of a reduced dropout rate (odds ratio <1) was 91.6%.

Conclusion: Targeted training guidance as part of human performance management may help to reduce fitness-related dropout rates among SOF candidates.