Bmj Military Health最新文献

Future warfare will likely involve near-peer or peer-peer conflict in which there is a great risk of mass casualty scenarios. Because of anti-access and area denial, air superiority will not be guaranteed, which will hamper rapid evacuation of casualties as well as resupply. Under such circumstances, military medical personnel may be forced, due to the constraints of the battlefield and tactical necessity to return servicemembers to duty, to implement reverse triage in which servicemembers with less severe injuries are treated first. However, reverse triage is potentially incongruent with international humanitarian law. Furthermore, should reverse triage need to be implemented, from the extant military doctrine it is not certain when this would be appropriate or the steps that might be followed, which highlight the gaps that exist before reverse triage should be considered as military doctrine on the battlefield. Lastly, we question the psychological impact that reverse triage could portend on military medical personnel, unit morale and unit cohesion. While there have been recent recommendations that reverse triage might need to be implemented in a near-term future conflict, these issues linger. It is time for Western militaries to assess the merits of reverse triage and the potential drawbacks.

IntroductionUS Army Initial Entry Training (IET) aims to develop general fitness and conditioning among large groups of trainees. Despite group mean improvement in physical fitness during IET, some trainees experience substantial gains and others experience no improvement or even declines in fitness. The purpose of this study was to examine the associations between trainee baseline fitness (Army Physical Fitness Test (APFT), the primary fitness assessment at the time of data collection) or estimated baseline body fat (%BF) and the change in fitness by the end of IET.

Methods: Trainee (n=774 men, 195 women) APFT performance data were obtained, and baseline anthropometrics were used to estimate %BF. APFT performance change (final-baseline) was analysed directly (t-tests) or by quartiles of baseline APFT performance or %BF (analysis of variance). Cochran-Armitage χ² for linear trend test and risk ratios allowed for comparison against the lowest initial performance referent quartile (Q1), providing the likelihood of fitness improvements. Significance was set at p≤0.05.

Results: Performance improved (p<0.01) on all final APFT events for men and women, respectively (push-ups: +38.4% and +91.8% repetitions; sit-ups: +26.8% and +33.5% repetitions; 2-mile run: -9.6% and -10.4% time). Significant trends in both sexes indicated that moving from low-to-high initial APFT fitness quartiles, trainees were increasingly less likely to improve their fitness. Specifically, men and women in the highest initial fitness quartiles (Q4) were 22%-32% and 25%-34% less likely (p<0.01) to improve, respectively, versus the within-sex lowest initial fitness quartiles (Q1). Only the male trainee's 2-mile run time change was related to the initial %BF.

Conclusions: Although most trainees' fitness improved by the end of IET, the likelihood and magnitude of improvement were clearly associated with initial fitness levels. Attention to individualised conditioning and training intensity in the physical readiness training programme of instruction may optimise training strategies across all trainee conditioning levels.

Introduction: The introduction of wireless sensors will enable military care providers to continuously and remotely assess/monitor vital signs. Prediction models are needed to use such data adequately and aid military care providers in their on-scene decision-making to optimise prehospital triage and improve patient outcomes.

Methods: A prospective cohort comprising data from eight Emergency Medical Services and seven inclusive trauma regions was used to develop and validate prediction models that could aid military care providers in their prehospital triage decisions. Healthy (American Society of Anesthesiologists physical status classification 1 or 2) admitted adult trauma patients (aged ≥16 and ≤50 years), who suffered from a trauma mechanism that could occur to military personnel and were transported by ambulance from the scene of injury to a hospital, were included. A full model strategy was used, including prehospital predictors that are expected to be automaticly collectible by wireless sensors or to be incorporated in a personalised device that could run the models. Models were developed to predict early critical-resource use (ECRU), severe head injury (Abbreviated Injury Scale (AIS) ≥4), serious thoracic injury (AIS ≥3) and severe internal bleeding (>20% blood loss). Model performance was evaluated in terms of discrimination and calibration.

Results: Prediction models were developed with data from 4625 patients (80.0%) and validated with data from 1157 patients (20.0%). The models had good to excellent discriminative performance for the predicted outcomes in the validation cohort, with an area under the curve of 0.80 (95% CI 0.76 to 0.84) for ECRU, 0.83 (0.76 to 0.91) for severe head injury, 0.75 (0.70 to 0.80) for serious thoracic injury and 0.85 (0.78 to 0.93) for severe internal bleeding. All models showed satisfactory calibration in the validation cohort.

Conclusion: The developed models could reliably predict outcomes in a simulated military trauma population and potentially support prehospital care providers in their triage decisions.

Introduction: The present study determined the (1) day-to-day reliability of basal heart rate (HR) and HR variability (HRV) measured by the Equivital eq02+ LifeMonitor and (2) agreement of ultra short-term HRV compared with short-term HRV.

Methods: Twenty-three active-duty US Army Soldiers (5 females, 18 males) completed two experimental visits separated by >48 hours with restrictions consistent with basal monitoring (eg, exercise, dietary), with measurements after supine rest at minutes 20-21 (ultra short-term) and minutes 20-25 (short-term). HRV was assessed as the SD of R-R intervals (SDNN) and the square root of the mean squared differences between consecutive R-R intervals (RMSSD).

Results: The day-to-day reliability (intraclass correlation coefficient (ICC)) using linear-mixed model approach was good for HR (0.849, 95% CI: 0.689 to 0.933) and RMSSD (ICC: 0.823, 95% CI: 0.623 to 0.920). SDNN had moderate day-to-day reliability with greater variation (ICC: 0.689, 95% CI: 0.428 to 0.858). The reliability of RMSSD was slightly improved when considering the effect of respiration (ICC: 0.821, 95% CI: 0.672 to 0.944). There was no bias for HR measured for 1 min versus 5 min (p=0.511). For 1 min measurements versus 5 min, there was a very modest mean bias of -4 ms for SDNN and -1 ms for RMSSD (p≤0.023).

Conclusion: When preceded by a 20 min stabilisation period using restrictions consistent with basal monitoring and measuring respiration, military personnel can rely on the eq02+ for basal HR and RMSSD monitoring but should be more cautious using SDNN. These data also support using ultra short-term measurements when following these procedures.

Introduction: Historically, diseases and non-battle injuries (DNBI) typically stand for 70%‒95% of all medical events during military missions. There is, however, no comprehensive compilation of medical statistics for Swedish soldiers during deployment.

Method: During United Nations Multidimensional Integrated Stabilization Mission in Mali, climate data and medical outpatient health surveillance data were compiled for Swedish soldiers deployed to Timbuctoo, between 2015 and 2019. Correlations between climate data and medical outpatient health surveillance data were analysed.

Results: Battle injuries accounted for 0.4% of the visits to healthcare, while diseases accounted for 53.6%, and non-battle injuries for 46%, the majority being musculoskeletal injuries. The combination of high temperature, humidity, sun radiation and good visibility, during summer rotation weeks, caused more events of injuries and heat stress than any other period.

Conclusion: Musculoskeletal injuries were the major cause for visits to the Swedish camp hospital. Injuries and heat stress increased during periods of high temperature, humidity, sun radiation and good visibility. Lack of medical data, i.e. unknown number of unique patients seeking healthcare, cause codes not always connected to a primary diagnosis, and revisits not being connected to a diagnose, complicated interpretation of health risk factors.

Introduction: The Western lifestyle challenges national defence. Inactivity, obesity, high BP and elevated lipid and glucose levels as well as tobacco use all increase cardiometabolic risk. The present study was thus aimed at investigating the health and physical activity of employees in a military environment, concentrating on comparisons between soldiers and civilians.

Methods and design: A total of 260 employees from 6 brigades were included in the present study. Health status was evaluated with body composition, cardiometabolic risk markers from laboratory samples and a questionnaire concerning lifestyle habits. Body composition was assessed by means of body mass, body mass index, fat percentage and waist circumference. Furthermore, physical activity was examined by the aid of accelerometer recordings for a 2-week period, and physical fitness via aerobic and muscle fitness tests. Finally, upper-quartile active and lower-quartile passive participants were compared, by incorporating mean daily step counts.

Results: When standardised by gender, there were no differences between the soldiers and civilians except for the muscle fitness test, in which soldiers performed better. The mean (±SD) moderate to vigorous activity was 0.9±0.3 hours/day in male soldiers and 1.0±0.4 hours/day in male civilians, and respectively sedentary behaviour was 9.5±1.4 hours/day in male soldiers and 8.9±1.7 hours/day in male civilians. The mean (±SD) low-density lipoprotein values were 3.28±0.84 mmol/L in male soldiers and 3.36±0.86 mmol/L in male civilians. In comparing soldiers and civilians, statistically significant differences were observed in body composition, physical fitness, insulin, fasting glucose, triglycerides and high-density lipoprotein values between the upper-quartile active and lower-quartile passive participants, but no difference in low-density lipoprotein values was noticed.

Conclusions: Sedentary behaviour and elevated low-density lipoprotein values seem to increase cardiometabolic disease risk among participants, even if they meet the weekly physical activity demands.

Introduction: Limited research is available on the bone health of female warfighters graduating from combat leadership courses like the US Army Ranger Training Course since combat roles opened to women in 2015. This investigation aimed to characterise the bone density, microarchitecture and strength of a small cohort of these female elite warfighters (FEW) to aid in understanding the physical resilience necessary for women to succeed in such courses.

Methods: FEW (n=11) were assessed for body composition and whole-body areal bone mineral density (aBMD) and content (BMC) by DXA, bone microarchitecture at two distal tibia sites by high-resolution peripheral quantitative CT (HR-pQCT) and health and lifestyle outcomes by survey. Two female comparison cohorts (CC) of Army basic combat trainees were matched (3:1), to provide context to the FEW.

Results: FEW were similar to CC1 and CC2 in height, and lower in body fat (p<0.05). FEW whole-body aBMD and BMC were higher than CC1 (both p<0.01, Cohen's D=0.233 and 0.785, respectively). HR-pQCT measures demonstrated greater total density (13.4%; p=0.01), bone volume fraction (12.9%; p=0.03) and 26.0% higher estimated failure load (p<0.01) in the FEW compared with CC1 at the metaphysis. At the diaphysis, FEW tibiae had 10.2% higher estimated compressive stiffness and 10.3% higher estimated failure load (both p<0.05) than CC2 with no differences in other bone health measures. Lifestyle and health factors were similar between groups.

Conclusions: Greater BMC and more favourable bone properties at the distal tibia were observed in the FEW compared with basic combat trainees, supplementing previous findings of exceptional body composition of women graduating from elite combat leadership courses. Considering the prevalence of BSI in female warfighters, further study is warranted to determine how bone status affects probability of course success.