Severe Spaceflight-Associated Neuro-Ocular Syndrome in an Astronaut With 2 Predisposing Factors.

Importance: Understanding potential predisposing factors associated with spaceflight-associated neuro-ocular syndrome (SANS) may influence its management. Objective: To describe a severe case of SANS associated with 2 potentially predisposing factors. Design, Setting, and Participants: Ocular testing of and blood collections from a female astronaut were completed preflight, inflight, and postflight in the setting of the International Space Station (ISS). Exposure: Weightlessness throughout an approximately 6-month ISS mission. Mean carbon dioxide (CO2) partial pressure decreased from 2.6 to 1.3 mm Hg weeks before the astronaut's flight day (FD) 154 optical coherence tomography (OCT) session. In response to SANS, 4 B-vitamin supplements (vitamin B6, 100 mg; L-methylfolate, 5 mg; vitamin B12, 1000 µg; and riboflavin, 400 mg) were deployed, unpacked on FD153, consumed daily through FD169, and then discontinued due to gastrointestinal discomfort. Main Outcomes and Measures: Refraction, distance visual acuity (DVA), optic nerve, and macular assessment on OCT. Results: Cycloplegic refraction was -1.00 diopter in both eyes preflight and +0.50 - 0.25 × 015 in the right eye and +1.00 diopter in the left eye 3 days postflight. Uncorrected DVA was 20/30 OU preflight, 20/16 or better by FD90, and 20/15 OU 3 days postflight. Inflight peripapillary total retinal thickness (TRT) peaked between FD84 and FD126 (right eye, 401 µm preflight, 613 µm on FD84; left eye, 404 µm preflight, 636 µm on FD126), then decreased. Peripapillary choroidal folds, quantified by surface roughness, peaked at 12.7 µm in the right eye on FD154 and 15.0 µm in the left eye on FD126, then decreased. Mean choroidal thickness increased throughout the mission. Genetic analyses revealed 2 minor alleles for MTRR 66 and 2 major alleles for SHMT1 1420 (ie, 4 of 4 SANS risk alleles). One-week postflight, lumbar puncture opening pressure was normal, at 19.4 cm H2O. Conclusions and Relevance: To the authors' knowledge, no other report of SANS documented as large of a change in peripapillary TRT or hyperopic shift during a mission as in this astronaut, and this was only 1 of 4 astronauts to experience chorioretinal folds approaching the fovea. This case showed substantial inflight improvement greater than the sensitivity of the measure, possibly associated with B-vitamin supplementation and/or reduction in cabin CO2. However, as a single report, such improvement could be coincidental to these interventions, warranting further evaluation.

Is point-of-care ultrasound accurate and useful in the hands of military medical technicians? A review of the literature.

Over the past decade, point-of-care ultrasound (US) use by nonphysician providers has grown substantially. The purpose of this article is to (1) summarize the literature evaluating military medics' facility at US, (2) more clearly define the potential utility of military prehospital US technology, and (3) lay a pathway for future research of military prehospital US. The authors performed a keyword search using multiple search engines. Each author independently reviewed the search results and evaluated the literature for inclusion. Of 30 studies identified, five studies met inclusion criteria. The applications included evaluation of cardiac activity, pneumothorax evaluation, and fracture evaluation. Additionally, a descriptive study demonstrated distribution of US exam types during practical use by Army Special Forces Medical Sergeants. No studies evaluated retention of skills over prolonged periods. Multiple studies demonstrate the feasibility of training military medics in US. Even under austere conditions, the majority of studies conclude that medic can perform US with a high degree of accuracy. Lessons learned from these studies tend to support continued use of US in out-of-hospital settings and exploration of the optimal curriculum to introduce this skill.

Fracture detection in a combat theater: four cases comparing ultrasound to conventional radiography.

Ultrasound (US) is rapid, non-invasive, simple, effective, and presents a viable and practical alternative to conventional radiography (CR) for the Special Forces Medical Sergeant (18D), particularly in the deployed setting. The authors present four cases that illustrate the ability of US used by the 18D to detect fractures in a combat theater. This success invites a debate as to what extent the Special Operations Forces (SOF) community should field US as it demonstrates a number of distinct advantages over the existing gold standard of portable conventional radiography.

Special operator level clinical ultrasound: an experience in application and training.

Over the past few decades, ultrasound has evolved from a radiology and subspecialist-centric instrument, to a common tool for bedside testing in a variety of specialties. The SOF community is now recognizing the relevancy of training medics to employ this technology for multiple clinical indications in the austere operating environment. In the Fall 2008 issue of Journal of Special Operations Medicine two of the authors described the concept of training SOF medics to employ portable ultrasound as a diagnostic aid. After over two years of concerted effort, the authors trained 29 out of 40 medics of a Special Forces battalion. Retrospective analysis of the quality assurance data for ultrasound studies conducted placed the 109 studies into six categories, allowing inference of trends in clinical indication for ultrasound exams as determined by the SOF medic-ultrasonographer. The resulting distribution suggests that indications for fractures and superficial applications are as prevalent as those for focused abdominal sonography in trauma (FAST) and pneumothorax exams. This analysis focuses on Special Operator Level Clinical Ultrasound (SOLCUS), an ultrasound training curriculum specifically for SOF medics, and helps appropriately prioritize its objectives. Despite the success of this experience, there are several issues requiring resolution before being able to integrate ultrasound training and fielding into the SOF medical armamentarium.