Bmj Military Health最新文献

Introduction: Travel to resource-limited settings is a known risk for acquisition of extended-spectrum β-lactamase-producing Enterobacterales (ESBL-PE) and carbapenem-resistant Enterobacterales (CRE), which are both associated with increased morbidity and mortality. We investigated the ESBL-PE and CRE baseline prevalence in British service personnel (SP).

Methods: SP provided faecal samples for research projects in several different settings, between September 2021 and April 2022. Bacterial colonies from faecal isolates were recovered from incubated ChromID ESBL plates (bioMérieux, Marcy-l'Étoile, France) and DNA extracted using Qiagen DNeasy extraction kits (Qiagen, UK). PCR to identify β-lactamase and CRE encoding genes was performed using the Rotor-Gene Q (RGQ) (Qiagen, UK), with positivity detected by RGQ software. Phenotypic assessment of antimicrobial susceptibility was not performed.

Results: Out of 250 personnel approached, 239 (85.5% men, median (IQR) age 31 (26-37) years) provided faecal samples suitable for analysis. The ESBL prevalence was 40/239 (16.7%), with ESBL-producing Escherichia coli detected in 39 (16.3%) samples and ESBL-producing Klebsiella pneumoniae in 1 (0.4%) sample. Combinations including Temoniera, sulfhydryl reagent variable (SHV), cefotaxime hydrolysing β-lactamase (Munich) (CTX-M) 1 and CTX-M 9 genes were detected in 18 (7.5%), 33 (13.8%) 16 (6.7%) and 8 (3.3%) samples, respectively. E. coli samples had mixtures of all four genotypes with SHV predominating. One (0.4%) sample carried all four gene types and the only K. pneumoniae sample carried a single SHV gene. No CRE were detected.

Conclusions: The prevalence of ESBL-PE in cohorts of SP closely matches that of civilian populations in England; however, we noted differences in ESBL genotype distribution. Potential exposure risks for SP from international travel and occupational trauma emphasise the need for repeated surveillance to characterise and detect changes in acquisition epidemiology and carriage of ESBL. Such prospective data have important antimicrobial stewardship implications in optimising clinical outcomes, controlling resistance and guiding empirical antibiotic formulary policy recommendations.

The evolving landscape of battlefield medicine forces medical planners to prepare for large-scale combat operations (LSCO) against peer adversaries, requiring reassessment of recent medical strategies. Despite lacking medical backing, the term 'golden day' has been used by senior military leaders to link the resuscitative benefits of the 'golden hour' to prolonged medical care through similar nomenclature. Pseudomedical terminology can easily enter the lexicon of commanders as attractive soundbites. However, articulating the evidence-based factors influencing mortality on the battlefield is critical to effectively articulate risk to commanders. The challenges of LSCO will be significant with increased casualty numbers and treatment constraints. Realistic medical and operational planning is critical to maximising survival, with a clear understanding of what can and cannot be achieved. Recent improvements in trauma care, such as early haemorrhage control, advanced prehospital care and rapid evacuation to surgical care, have significantly reduced mortality rates. Given the predictability of when casualties die from significant injuries, the absence of timely clinical interventions will increase avoidable battlefield deaths. If evacuation to surgical care is extended to 24 hours, many more casualties will die from potentially survivable injuries. Medical planners must recognise the potential challenges associated with LSCO including contested, delayed evacuation which predicts a tripling of mortality rates from 10% to 30%. Leaders must appreciate the unchanging human physiologic response to injury and historical combat casualty statistics when preparing commanders and politicians for the excess in mortality during LSCO. Without candour, plans will be unrealistic, causing non-medical leaders and the public to be unprepared.

Osteoarthritis (OA) affects over 600 million worldwide, is one of the leading causes of disability and has a significant burden of morbidity. There are multiple modifiable and non-modifiable risk factors, with professional and tactical athletes at higher risk than other occupational groups. Without specific anti-OA pharmacological agents, clinicians may feel helpless. However, primary, secondary and tertiary preventative strategies can slow or prevent OA development or progression. There are many modifiable risk factors which, if targeted, can contribute to an improvement in the experience of people living with OA. Radiological features of OA may signify the presence of 'the disease'; however, the pain and symptoms experienced may be more accurately described as 'the illness'. Targeting both, using a combination of the medical and biopsychosocial models of care, will improve the overall experience.This paper outlines some easily adoptable general and specific strategies to help manage this common and disabling condition, focused on improving joint healthspan, not just joint lifespan. They include education and communication, empowering individuals to confidently self-manage their condition with access to healthcare resources when required. A holistic package, including support for sleep, diet and weight loss, physical activity and specific home-based exercise routines, with appropriate analgesia when needed, can all improve OA illness and potentially slow OA disease development or progression. Clinicians should feel confident that there are many opportunities to intervene and mitigate the risk factors of OA, using various preventative strategies, especially in a young, physically active population with functional occupational or recreational demands.

Introduction: Intraosseous (IO) administration of medication, fluids and blood products is accepted practice for critically injured patients in whom intravenous access is not immediately available. However, there are concerns that high intramedullary pressures resulting from IO infusion may cause bone marrow intravasation and subsequent fat embolisation. The aim of this systematic review is to synthesise the existing evidence describing fat intravasation, fat embolism and fat embolism syndrome (FES) following IO infusion.

Methods: A systematic search of CINAHL, MEDLINE and Embase was undertaken using the search terms "intraosseous", "fat embolism", "fat intravasation" and "fat embolism syndrome". Two authors independently screened abstracts and full texts, against eligibility criteria and assessed risk of bias. A grey literature search (including references) was undertaken. Inclusion criteria were: all human and animal studies reporting novel data on IO-associated fat emboli. This systematic review was conducted in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analysis.

Results: 22 papers were identified from the search, with a further 5 found from reference lists. N=7 full papers met inclusion criteria. These papers were all translational animal studies. The overall risk of bias was high. Studies demonstrated that fat intravasation and fat embolisation are near universal after IO infusion, but of uncertain clinical significance. The initial IO flush appears to cause the highest intramedullary pressure and highest chance of fat intravasation and embolisation. No conclusions could be drawn on FES.

Conclusions: IO catheters remain a useful intervention in the armamentarium of trauma clinicians. Although their use is widely accepted, there is a paucity of evidence investigating fat embolisation in IO infusions. Despite this, pulmonary fat emboli after IO infusion are very common. The existing data are of low quality with a high risk of bias. More research is needed to address this important subject.

Prospero registration number: CRD42023399333.

Introduction: Dismounted blast has the potential to cause life-threatening injuries to multiple simultaneous casualties, including injury to the cervical spine (c-spine). Spinal immobilisation can be costly in terms of time and personnel required to apply and sustain it. C-spine 'clearing' tools frequently do not apply to the blast-injured casualty, so clinical judgement must be used to determine those requiring c-spine immobilisation. This will be strongly influenced by the likelihood of such an injury, but currently, the incidence of c-spine injury in dismounted blasts is not known.

Methods: We searched PubMed, EMBASE and the Cumulative Index to Nursing and Allied Health for original research reporting the number of patients suffering c-spine injury as a result of the dismounted blast, as well as indices of injury severity such as incidence of limb amputation. Rates were combined to give an overall incidence. The systematic review was preregistered with PROSPERO (CRD42024527592).

Results: 2775 unique studies were identified, 13 of which were analysed. Reported incidences of c-spine injuries ranged from 0% to 5.85% across all 13 studies, and unstable injuries ranged from 0% to 1.23% in the nine studies in which this could be calculated. After excluding one study due to an overlapping population, in 7889 patients the rate of c-spine injury was 0.89%. In the 4618 patients for which the incidence of unstable c-spine injury could be calculated, the rate was 0.30%. There was no correlation between the rate of amputation and the rate of c-spine injury (Spearman's ρ=0.226, p=0.667).

Conclusion: Dismounted blasts result in a very low rate of c-spine injury. The populations sampled included a number of seriously injured casualties with potentially life-threatening wounds, such as limb amputation. We recommend deprioritising c-spine control in dismounted victims of the blast in favour of focusing the limited time and resources on addressing potentially life-threatening injuries.

Introduction: Administering supplemental oxygen is a standard of care for trauma casualties to minimise the deleterious effects of hypoxaemia. Forward deployment of oxygen using pressurised cylinders is challenging, for example, logistics (weight and finite resource) and environmental risk (fire and explosion). Oxygen concentrators may overcome these challenges. Although previous studies successfully demonstrated fractional inspired oxygen (FiO₂) >0.8 using oxygen concentrators and ventilators, the systems did not fulfil the size, weight and power requirements of agile military medical units. This study evaluated whether a modular system of commercially available clinical devices could supply high FiO₂ to either ventilated or spontaneously breathing casualties.

Methods: As a proof of principle, we configured an Inogen One G5 oxygen concentrator, Ventway Sparrow ventilator and Wenoll rebreather system to ventilate a simulated lung (tidal volume 500 mL). Casualty oxygen consumption (gas withdrawal inspiratory limb) and carbon dioxide (CO₂) production (CO₂ added expiratory limb) were simulated (respiratory quotient of 0.7-0.8). Three circuit configurations were evaluated: open (supplementary oxygen introduced into air inlet of ventilator); semiclosed (ventilator replaces rebreather bag of Wenoll, oxygen connected to either ventilator or Wenoll); and semiclosed with reservoir tubing (addition of 'deadspace' tube between ventilator patient circuit and Wenoll). Data presented as mean and 95% reference range.

Results: There were modest increases in FiO₂ with increasing Inogen settings in 'open' configuration 0.23 (0.23-0.24) and 0.30 (0.28-0.32) (Inogen output 420 and 1260 mL/min, respectively). With the 'semiclosed' configuration and oxygen added directly into rebreather circuit, FiO₂ increased to 0.36 (0.36-0.37). The addition of the 'reservoir tubing' elevated FiO₂ to 0.78 (0.71-0.85). FiO₂ remained stable over a 4-hour evaluation period. Fractional inspired carbon dioxide CO₂ increased over time, reaching 0.005 after 170 (157-182) min.

Conclusion: Combining existing lightweight devices can deliver high (>0.8) FiO₂ and offers a potential solution for the forward deployment of oxygen without needing pressurised cylinders.