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With the prevalence of carbon fiber reinforced polymers (CFRPs) in aerospace platforms, there is a need to better understand radiative heat transport through the material. A laboratory experiment was constructed and computational Monte Carlo (MC) model optimized to quantify and understand the laser-scattering properties of CFRPs. The transmission data were analyzed by a zonal MC (ZMC) method to determine the material’s albedo and extinction coefficient, which can then be used for platform-level aerospace models to predict heat transfer more accurately through CFRP structures. This paper considers the effects of nodal, substrate, and detector plane sizing, as well as laser beam parameters, on matching albedo and extinction coefficient predictions from the ZMC method to experimental test data. Average albedo values for IM7/977-3 CFRP using the anchored ZMC method are 0.78 and 0.81 with one-ply and two-ply samples, respectively, having standard deviations of 0.11 and 0.09. Extinction coefficient predictions are 109.4 and [Formula: see text] with standard deviations of 28.3 and [Formula: see text] for one-ply and two-ply samples.

Posttraumatic stress disorder (PTSD), which may develop following exposure to severe trauma, can occur in all people at any age. PTSD affects approximately 10 million Americans, with an incidence of approximately 3.5% diagnosed every year. Elite athletes are not immune to posttraumatic stress. While difficult to precisely quantify, an estimated 1 in 8 elite athletes suffers from PTSD. Because of its complex presentation, PTSD can be challenging to diagnose and effectively treat in athletes. Several barriers unique to elite athletes exist which may inadvertently delay or prevent access to the appropriate clinical experts. Several best practice models for mental health screening in elite athletes have been developed in the past decade. Treatment of PTSD in the athlete population is similar to trauma-informed treatment in the general population, but should involve the athlete's multidisciplinary team of clinical experts to account for unique demands and preferences in the context of sport.

Origami, the ancient art of paper folding, has shown its potential as a versatile platform to design various reconfigurable structures. The designs of most origami-inspired architected materials rely on a periodic arrangement of identical unit cells repeated throughout the whole system. It is challenging to alter the arrangement once the design is fixed, which may limit the reconfigurable nature of origami-based structures. Inspired by phase transformations in natural materials, here we study origami tessellations that can transform between homogeneous configurations and highly heterogeneous configurations composed of different phases of origami unit cells. We find that extremely localized and reprogrammable heterogeneity can be achieved in our origami tessellation, which enables the control of mechanical stiffness and in-situ tunable locking behavior. To analyze this high reconfigurability and variable stiffness systematically, we employ Shannon information entropy. Our design and analysis strategy can pave the way for designing new types of transformable mechanical devices. Origami-inspired metamaterials are attractive for their programmable shape-shifting properties but are typically characterized by low structural rigidity. Here, 3D heterogeneous origami structures display highly reconfigurable mechanical properties, including finely controllable and reversible stiffness variation.

Introduction Ultrasound-guided stellate ganglion block (SGB) is an injection of local anesthetic (8mL of 0.5% ropivacaine) in the neck to temporarily block the cervical sympathetic trunk which controls the body’s fight-or-flight response. This outpatient procedure takes less than thirty minutes and is immediately effective. Our goal was to determine if a left-sided stellate ganglion block is effective for treating posttraumatic stress disorder (PTSD) symptoms. While right-sided SGB has been extensively studied, left-sided SGB has not been formally evaluated for this indication. Materials and Methods Our hypothesis was that patients who fail to improve following a right-sided SGB will report significant improvement following a left-sided SGB. A retrospective chart review was conducted for patients who received SGB for PTSD symptoms between August 2019 and March 2020. All procedures were performed at an established musculoskeletal practice by the same anesthesia/pain fellowship-trained physician. Subjects included those who underwent a left-sided SGB (LSGB) only after non-response to a right-sided SGB (RSGB). Non-response was defined as less than 10 points of improvement on a PTSD Checklist (PCL-5). Results Out of 205 patients, 20 did not respond to an RSGB and were included in our analysis. Ten of these patients subsequently received an LSGB, and 90% responded favorably (PCL-5 mean improvement = 28.3 points). Conclusions Based on our sample of 205 patients receiving SGB for PTSD, we concluded that at least 4.4% did not respond to a right-sided SGB but did have a significant response to a left-sided SGB.

Military resilience research is increasing due to the growing literature associating resilience with stress adaptation. This study aimed to investigate which physiological stress adaptation components were associated with resilience in Special Operations Forces combat service members. Special Operations Forces combat service members (n = 117) self-reported resilience (ER89) and lifetime clinician-confirmed mild traumatic brain injury history. Participants also underwent transcranial Doppler ultrasonography to measure middle cerebral artery velocity during rest and a breath-holding task. Neither resilience nor mild traumatic brain injury history was significantly associated with middle cerebral artery velocity percent increase following breath-holding; younger Special Operations Forces combat service members had a higher percent increase in middle cerebral artery velocity following a breath-holding task. Resilience was negatively associated with time to return to baseline middle cerebral artery velocity following peak velocity; whereas, mild traumatic brain injury history did not have a significant association. The Special Operations Forces combat service members that scored higher in resilience tended to return to baseline middle cerebral artery velocity following peak velocity faster than their less resilient counterparts. More resilient Special Operations Forces combat service members recovered faster from physiological stress (breath-holding) than less resilient counterparts. This is the first study to investigate resilience and cerebrovascular stress response and recovery in this population. Our initial findings indicated that the Ego Resiliency Scale may be an optimal resilience psychometric and should be used to evaluate effective military resilience trainings, which aim to improve performance and mental health.

Our aim in this study was to psychometrically test resilience assessments (Ego Resiliency Scale [ER89], Connor-Davidson Resilience Scale [CD-RISC 25], Responses to Stressful Experiences Scale [RSES short-form]) and describe resilience levels in a Special Operations Forces (SOF) combat sample.Fifty-eight SOF combat Servicemembers either entering SOF (career start; n = 38) or having served multiple years with their SOF organization (mid-career; n = 20) self-reported resilience, mild traumatic brain injury (mTBI) history, and total military service.All resilience metrics demonstrated acceptable internal consistency, but ceiling effects were found for CD-RISC and RSES scores. ER89 scores were moderate on average. ER89 scores were higher in SOF career start than mid-career Servicemembers (ηρ2 = 0.07) when accounting for the interaction between SOF career stage and total military service (ηρ2 = 0.07).SOF mid-career Servicemembers had similar ER89 resilience scores with more total military service. The SOF career start combat Servicemembers had higher ER89 measured resilience with less total military service only, potentially showing a protective effect of greater service before entering SOF.The ER89 may be a more optimal military resilience metric than the other metrics studied; longitudinal research on SOF combat Servicemember resilience is warranted.

The purpose of this study was to investigate how concussion history affects neurovascular coupling in Special Operations Forces (SOF) combat Soldiers. We studied 100 SOF combat Soldiers [age = 33.5 ± 4.3 years; height = 180.4 ± 6.0 cm; 55 (55.0%) with self-reported concussion history]. We employed transcranial Doppler (TCD) ultrasound to assess neurovascular coupling (NVC) via changes in posterior cerebral artery (PCA) velocity in response to a reading and a visual search task. Baseline TCD data were collected for 2 min. NVC was quantified by the percent change in overall PCA response curves. We employed linear mixed effect models using a linear spline with one knot to assess group differences in percent change observed in the PCA velocity response curves between SOF combat Soldiers with and without a concussion history. Baseline PCA velocity did not significantly differ (t98 = 1.28, p = 0.20) between those with and without concussion history. Relative PCA velocity response curves did not differ between those with and without a concussion history during the reading task (F1,98 = 0.80, p = 0.37) or the visual search task (F1,98 = 0.52, p = 0.47). When assessing only SOF combat Soldiers with a concussion history, differential response to task was significantly greater in those with 3 or more concussions (F1,4341 = 27.24, p < 0.0001) relative to those with 1-2 concussions. Despite no main effect of concussion history on neurovascular coupling response in SOF combat Soldiers, we observed a dose-response based on lifetime concussion incidence. While long-term neurophysiological effects associated with head impact and blast-related injury are currently unknown, assessing NVC response may provide further insight into cerebrovascular function and overall physiological health.

The stellate ganglion block (SGB) procedure has been used successfully for over 10 years to treat post-traumatic stress symptoms in thousands of US military service members, civilians, and veterans in select hospitals in Europe and North America. Primarily through targeting the autonomic nervous system, the SGB procedure serves as an invaluable adjunct to trauma-focused psychotherapy. Without published best practices for emerging therapies, clinicians are left on their own to determine how best to apply new treatments to their patient populations. The aim of this qualitative research was to compile attitudes and recommendations from therapists with expertise in using SGB for treating symptoms of post-traumatic stress disorder, so that their experiences could be disseminated widely to clinicians without SGB expertise. An 18-item survey was developed and distributed electronically to a group of behavioral health professionals of various specialties between May and June 2020. Of surveyed behavioral health clinicians with personal experience incorporating SGB into their trauma-focused psychotherapy, 95% of respondents would recommend SGB to a colleague as a useful tool for the treatment of trauma-related disorders. SGB was rated at least as useful as the most valuable interventions listed in the American Psychological Association Clinical Practice Guideline for the Treatment of Post-traumatic Stress Disorder with 100% of respondents characterizing SGB as ‘Very Beneficial’ or ‘Somewhat Beneficial’, and 0 respondents characterizing SGB as ‘Not Helpful’ or ‘Harmful’. Given the feedback from this study, behavioral health providers should consider using SGB in conjunction with standard trauma-focused care.

Background Special Operations Forces (SOF) combat soldiers are frequently exposed to blast and blunt neurotrauma, most often classified as mild traumatic brain injury (mTBI). Repetitive mTBI may increase the risk of developing long-term neurological sequelae. Identifying changes in neuroinflammatory biomarkers before chronic conditions emerge could serve as preliminary evidence of developing neuropathology. Objective To determine the effects of mTBI history, lifetime mTBI incidence, and recency on blood biomarker concentrations of axonal protein neurofilament light (NfL), glycolytic enzyme neuron-specific enolase (NSE), astrocyte-expressed S100 calcium-binding protein B (S100B), and neurotrophic cytokine interleukin-6 (IL-6) in healthy, active duty SOF combat soldiers. Methods Self-reported mTBI history/recency and fasted blood samples were collected in this cross-sectional study of 104 asymptomatic SOF combat soldiers. Biomarker concentrations were quantified using commercial enzyme-linked immunosorbent assays. Mann-Whitney U and Kruskal-Wallis tests were used to compare groups. Post hoc tests with appropriate corrections were conducted as warranted. Results Soldiers with mTBI history had higher NSE concentrations than those without (z = -2.60, P = .01). We also observed significant main effects of lifetime mTBI incidence on NSE (χ(3) = 9.52, P = .02) and S100B (χ(3) = 8.21, P = .04) concentrations and a significant main effect of mTBI recency on NfL concentration (χ(2) = 6.02, P = .049). Conclusion The SOF combat soldiers with mTBI history had increased NSE. Longitudinal studies in this population are needed due to between-subject heterogeneity in biomarker concentrations. The NfL concentrations in our SOF combat soldiers-regardless of mTBI history or recency-were similar to values previously reported in civilian acute TBI patients.

Introduction Special Operations Forces (SOF) combat arms and combat support Soldiers are at risk for impaired mental health, such as mood- and stress-related disorders, due to operational and training demands. Additionally, these individuals experience high risk for sustaining mild traumatic brain injury (mTBI). These mTBIs have also been linked to negative psychological outcomes, such as anxiety and depressive symptoms. Studying mental illnesses and their related symptoms alone does not fully address mental health, which may be better understood by 2 separate but overlapping continua measuring both mental illness and subjective well-being (ie, emotional, psychological, and social well-being). Due to the lack of research in this area, current mental health symptoms in active SOF combat Soldiers in relation to mTBI warrants investigation. Materials and Methods In this study, 113 SOF combat and combat support Soldiers completed self-report psychological and mTBI history measures during an in-person laboratory setting. These psychometric measures included (1) psychological distress (Brief Symptom Inventory 18), (2) anxiety (Generalized Anxiety Disorder 7-item), (3) posttraumatic stress (PTSD Checklist for DSM-5), (4) somatization (Patient Health Questionnaire-15), and (5) subjective well-being (Mental Health Continuum Short Form). Results On average, SOF combat Soldiers endorsed moderate well-being and low psychological distress, somatization, posttraumatic stress, and anxiety. Most SOF combat Soldiers had sustained 1 or more mTBI. We observed mTBI history had significant effects on each dependent variable in the expected directions. History of more mTBIs, controlling for age, was associated with lower subjective well-being as well as higher psychological distress, somatization, posttraumatic stress, and anxiety symptoms. Conclusion Although SOF combat Soldiers reported relatively adaptive mental health symptoms across participants, there was considerable variance in the measures reported. Some of the variance in mental health symptoms was accounted for by mTBI history while controlling for age, with reporting higher numbers of lifetime mTBIs and older age being associated with worse mental health symptoms. Longitudinal investigations into these associations and their impact on Soldier performance is warranted.

The purpose of this study was to investigate how concussion history affects neurovascular coupling in Special Operations Forces (SOF) combat Soldiers. We studied 100 SOF combat Soldiers [age = 33.5 ± 4.3 years; height = 180.4 ± 6.0 cm; 55 (55.0%) with self-reported concussion history]. We employed transcranial Doppler (TCD) ultrasound to assess neurovascular coupling (NVC) via changes in posterior cerebral artery (PCA) velocity in response to a reading and a visual search task. Baseline TCD data were collected for 2 min. NVC was quantified by the percent change in overall PCA response curves. We employed linear mixed effect models using a linear spline with one knot to assess group differences in percent change observed in the PCA velocity response curves between SOF combat Soldiers with and without a concussion history. Baseline PCA velocity did not significantly differ (t

The present study investigated Special Operations Forces (SOF) combat Servicemember mental health at different SOF career stages in association with resilience.Fifty-eight SOF combat Service Members either entering SOF (career start; n=38) or multiple years with their SOF organization (mid-career; n=20) self-reported mild traumatic brain injury (TBI) history, resilience, subjective well-being, depression, anxiety, and posttraumatic stress. Poisson regression analyses were employed to test SOF career stage differences in each mental health symptom using resilience, while accounting for other pertinent military factors.There were significant interaction effects of SOF career stage and resilience on mental health symptoms. SOF career start combat Servicemembers endorsed lower depression and posttraumatic stress and higher subjective well-being with higher resilience, but these associations between resilience and mental health symptoms were not seen in SOF mid-career Servicemembers.Although preliminary, the adaptive association between resilience and mental health seemed to be blunted in combat Servicemembers having served multiple years in SOF. This information informs research to provide evaluation tools to support prophylactic performance and long-term health preservation in military populations.

The purpose of this study was to investigate how concussion history affects cerebrovascular reactivity (CVR) in Special Operations Forces (SOF) combat soldiers. We studied 104 SOF soldiers [age = 33.5 ± 4.3 years; height = 179.7 ± 6.3 cm; 59 (56.7%) with self-reported concussion history]. We employed transcranial Doppler (TCD) ultrasound to measure middle cerebral artery (MCA) velocity. Baseline TCD data were collected for 2 min. Changes in MCA velocity were measured in response to five breath-holding trials and five hyperventilation trials. Cerebrovascular reactivity was quantified by the breath-holding index (BHI), vasomotor reactivity reserve (VMRr), and percent change in overall response curves. Independent t tests were employed to assess group differences in BHI, and VMRr values. We employed mixed effects models with quadratic mean structures to assess group differences in percent change MCA velocity response curves. There were no significant group differences in BHI (t102 = 0.04, p = 0.97) or VMRr (t102 = -0.33, p = 0.75). There were no group differences in relative MCA velocity response curves during the breath-holding task (F1,5092 = 0.19, p = 0.66) or during the hyperventilation task (F1,5092 = 0.41, p = 0.52) between SOF soldiers with and without a self-reported concussion history. If CVR deficits exist immediately post-concussion, our study suggests that these deficits recover over time in this population. While long-term neurophysiological effects of blast-related injury are currently unknown, assessing CVR response may provide further insight into cerebrovascular function and overall physiological health following blast exposure.

Importance This is the first multisite, randomized clinical trial of stellate ganglion block (SGB) outcomes on posttraumatic stress disorder (PTSD) symptoms. Objective To determine whether paired SGB treatments at 0 and 2 weeks would result in improvement in mean Clinician-Administered PTSD Scale forDSM-5(CAPS-5) total symptom severity scores from baseline to 8 weeks. Design, Setting, and Participants This multisite, blinded, sham-procedure, randomized clinical trial used a 2:1 SGB:sham ratio and was conducted from May 2016 through March 2018 in 3 US Army Interdisciplinary Pain Management Centers. Only anesthesiologists performing the procedures and the procedure nurses were aware of the intervention (but not the participants or assessors); their interactions with the participants were scripted and limited to the 2 interventions. Active-duty service members on stable psychotropic medication dosages who had a PTSD Checklist–Civilian Version (PCL-C) score of 32 or more at screening were included. Key exclusion criteria included a prior SGB treatment, selected psychiatric disorders or substance use disorders, moderate or severe traumatic brain injury, or suicidal ideation in the prior 2 months. Interventions Paired right-sided SGB or sham procedures at weeks 0 and 2. Main Outcomes and Measures Improvement of 10 or more points on mean CAPS-5 total symptom severity scores from baseline to 8 weeks, adjusted for site and baseline total symptom severity scores (planned a priori). Results Of 190 screened individuals, 113 (59.5%; 100 male and 13 female participants; mean [SD] age, 37.3 [6.7] years) were eligible and randomized (74 to SGB and 39 to sham treatment), and 108 (95.6% of 113) completed the study. Baseline characteristics were similar in the SGB and sham treatment groups, with mean (SD) CAPS-5 scores of 37.6 (11.2) and 39.8 (14.4), respectively (on a scale of 0-80); 91 (80.0%) met CAPS-5 PTSD criteria. In an intent-to-treat analysis, adjusted mean total symptom severity score change was −12.6 points (95% CI, −15.5 to −9.7 points) for the group receiving SGB treatments, compared with −6.1 points (95% CI, −9.8 to −2.3 points) for those receiving sham treatment (P = .01). Conclusions and Relevance In this trial of active-duty service members with PTSD symptoms (at a clinical threshold and subthreshold), 2 SGB treatments 2 weeks apart were effective in reducing CAPS-5 total symptom severity scores over 8 weeks. The mild-moderate baseline level of PTSD symptom severity and short follow-up time limit the generalizability of these findings, but the study suggests that SGB merits further trials as a PTSD treatment adjunct. Trial Registration ClinicalTrials.gov identifier:NCT03077919

The human body is well adapted to dealing with small variations in atmospheric pressure. However when our pursuit of sport and recreation takes us to extreme altitudes or ocean depths, the change in surrounding pressure has the potential to cause significant morbidity. Sports with more extreme changes in atmospheric pressure such as skydiving and scuba diving commonly place the athlete at risk for barotrauma injuries, especially in the middle ear and sinuses. Middle ear barotrauma occurs when a pressure differential develops between the middle ear and the pressure outside of the tympanic membrane. Early symptoms include ear pain, dizziness, and muffled hearing. When extreme pressure gradients are not relieved, middle ear effusions and rupture of the tympanic membrane can occur. A similar mechanism and injury pattern occurs in the sinuses as well. With proper training and prevention strategies, athletes in these sports can protect themselves from most barotrauma injuries.

This study assessed which symptoms are most impacted following stellate ganglion block (SGB) used to treat post-traumatic stress disorder (PTSD) symptoms. 30 active military service members with combat-related PTSD self-referred to their physician and psychologist. Patients were offered a SGB as part of their treatment program. Primary outcome was the magnitude of change for the 17 items on the PTSD Checklist-Military (PCL-M), which was administered the week before SGB, 1 week after SGB, and 2 to 4 months later. Mean PCL-M score decreased from 49 at baseline to 32, 1 week after the procedure (p0.001). 2 to 4 months after SGB, patients maintained an average PCL-M of 32. Patients reported greatest improvement in the first week after SGB for the following symptoms: irritability or angry outbursts, difficulty concentrating, and sleep disturbance. 2 to 4 months later, patients reported greatest improvement in the following: feeling distant or cut off, feeling emotionally numb, irritability or angry outbursts, and difficulty concentrating. SGB is a safe procedure that may provide extended relief for all clusters of PTSD symptoms. As a result of the significant reduction in hyperarousal and avoidance symptoms observed, this study supports incorporation of SGB into PTSD treatment plans.

IntroductionAcupuncture is an accepted form of complementary medicine used by many athletes for a variety of reasons including musculoskeletal conditions (8). There is mounting evidence to support the use of acupuncture in treating common sports medicine conditions such as lateral epicondylopathy, p

Recreational scuba diving is a growing sport worldwide, with an estimated 4 million sport divers in the United States alone. Because divers may seek medical care for a disorder acquired in a remote location, physicians everywhere should be familiar with the physiology, injury patterns, and treatment of injuries and illnesses unique to the underwater environment. Failure to properly recognize, diagnose, and appropriately treat some diving injuries can have catastrophic results. In addition, recreational dive certification organizations require physical examinations for medical clearance to dive. This article will review both common and potentially life-threatening conditions associated with diving and will review current evidence behind fitness to dive considerations for elderly divers and those with common medical conditions.

Austere environments such as Africa pose clinical challenges, which are multiplied for Special Operations Forces (SOF) providers who must face these challenges with limited resources against the tyranny of distance. These limited resources apply not only to treatment tools but to diagnostic tools as well. Laboratory diagnostics may provide critical information in diagnosis, initial triage, and/or evacuation decisions, all of which may enhance a patient's survival. However, unlike in climate-controlled, fixed-facility hospitals, the deployed SOF provider must have access to a simple, reliable device for point-of-care testing (POCT) to obtain clinically meaningful data in a practical manner given the surroundings.

To measure key neurocognitive performance effects following stellate ganglion block (SGB) administered to treat post-traumatic stress disorder (PTSD) symptoms.Eleven patients diagnosed, screened, and scheduled for SGB to treat their PTSD symptoms were administered a panel of eight cognitive measures before and 1 to 3 weeks after undergoing this procedure. PTSD symptoms were evaluated using the Posttraumatic Stress Disorder Checklist-Military.One to three weeks post-SGB, none of the patients showed any statistically significant decline in neurocognitive performance. Rather, there was a clear trend in improvement, with four out of eight measures reaching statistical significance following SGB. All patients improved in PTSD symptoms with a mean improvement on Posttraumatic Stress Disorder Checklist-Military of 29.In this case series of 11 patients, SGB effectively treated PTSD symptoms and did not impair reaction time, memory, or concentration. Therefore, SGB should be considered as a viable treatment option for personnel with PTSD symptoms who will be placed in demanding conditions such as combat.

Chest pain of uncertain etiology (intermediate-risk chest pain [IR-CP]) constitutes a majority of acute chest pain presentations to emergency departments (EDs). A before- and-after trial of 2197 IR-CP patients transferred from the hospital's ED to one of three units-ED-based observation center (ED-OC), inpatient observation center (IN-OC), and inpatient units-compared mean cost, length of stay, and safety over a 2-year period. The mean per patient cost for management of IR-CP was lower in the ED-OC ($1642) than the IN-OC ($1910) or the inpatient units ($2785). The mean length of stay was shorter in the ED-OC (0.75 days) than in the IN-OC (1.18 days) or the inpatient units (2.16 days). Return rates were lower in the ED-OC at 7 days (0%) and at 6 months (0.45%) than the IN-OC (0% and 1.22%) or the inpatient units (0.77% and 3.67%). Overall hospital costs for managing IR-CP dropped significantly (12.5%) after the ED-OC was opened. ED-OCs provide a safe and cost-effective alternative to admission of IR-CP patients.

The natural health threats in Africa pose daunting clinical challenges for any provider, as evidenced by the current Ebola epidemic in West Africa, but the threat is multiplied for the Special Operations provider on the continent who faces these challenges with limited resources and the tyranny of distance. The majority of operationally significant health risks can be mitigated by strict adherence to a comprehensive force health protection plan. The simplest, yet most effective, technique for preventing mosquito-borne diseases is the prevention of mosquito bites with repellent, bed nets, and appropriate clothing in addition to chemoprophylaxis. Some of the more likely or lethal infectious diseases encountered on the continent include malaria, Chikungunya, dengue, human immunodeficiency virus, and Ebola. Venomous snakes pose a particular challenge since the treatment can be as deadly as the injury. Providers supporting African operations should educate themselves on the clinical characteristics of possible envenomations in their area while promoting snake avoidance as the primary mitigation measure. To succeed in Africa, the Special Operations provider must consider how to meet these challenges in an environment where there may not be reliable evacuation, hospitalization, or logistics channels.

Objective: Report the successful use of stellate ganglion blocks (SGBs) in 166 active duty service members with multiple combat deployments experiencing anxiety symptoms associated with post-traumatic stress disorder (PTSD). Background: Successful treatment of PTSD symptoms with SGB has been reported previously. This is the largest published case series evaluating SGB with a minimum of 3 months follow-up. Methods: Following clinical interview including administration of the PTSD Checklist (PCL), 166 service members with symptoms of PTSD elected to receive a SGB. All patients received a SGB on the right side at the level of the sixth cervical vertebrae (C6). The PCL was administered the day before treatment to establish a baseline, repeated 1 week later, and then monthly out to 3 months. A positive response was considered to be an improvement in the PCL score by 10 or greater points. Follow-up PCL scores from 3 to 6 months were obtained and analyzed for 166 patients. Results: In a military population with multiple combat deployments, over 70% of the patients treated had a clinically significant improvement in their PCL score which persisted beyond 3 to 6 months postprocedure. Conclusion: Selective blockade of the right cervical sympathetic chain at the C6 level is a safe and minimally invasive procedure that may provide durable relief from anxiety symptoms associated with PTSD.

This article regarding Special Operations Forces (SOF) medical operations in Africa is an introduction to a follow-on series of articles that will address in more detail pertinent medical topics which pertain to operations on the African continent. Medical operations in Africa require dynamic and systematic approaches that consider the myriad challenges, yet offer flexible solutions applied as situations and environments dictate. We believe this series of articles will be of high interest to readers and provide key information that will be germane to future SOF operations.

The elbow is a complex joint designed to withstand a wide range of dynamic exertional forces. The location and quality of elbow pain can generally localize the injury to one of the four anatomic regions: anterior, medial, lateral, or posterior. The history should include questions about the onset of pain, what the patient was doing when the pain started, and the type and frequency of athletic and occupational activities. Lateral and medial epicondylitis are two of the more common diagnoses and often occur as a result of occupational activities. Patients have pain and tenderness over the affected tendinous insertion that are accentuated with specific movements. If lateral and medial epicondylitis treatments are unsuccessful, ulnar neuropathy and radial tunnel syndrome should be considered. Ulnar collateral ligament injuries occur in athletes participating in sports that involve overhead throwing. Biceps tendinopathy is a relatively common source of pain in the anterior elbow; history often includes repeated elbow flexion with forearm supination and pronation. Olecranon bursitis is a common cause of posterior elbow pain and swelling. It can be septic or aseptic, and is diagnosed based on history, physical examination, and bursal fluid analysis if necessary. Plain radiography is the initial choice for the evaluation of acute injuries and is best for showing bony injuries, soft tissue swelling, and joint effusions. Magnetic resonance imaging is the preferred imaging modality for chronic elbow pain. Musculoskeletal ultrasonography allows for an inexpensive dynamic evaluation of commonly injured structures.

Acute mountain sickness (AMS) is the most common form of altitude illness affecting athletes and adventurists who work or play at elevations greater than 10,000 ft above mean sea level. Considerable research has been conducted to mitigate risk for those who work or play in environmental extremes. This article describes the experiences of a group of U.S. Army Special Operations soldiers who tested recommended doses of acetazolamide prophylaxis for AMS during six expeditions to elevations between 19,000 and 23,000 ft. In addition, we briefly review the literature as it pertains to prophylaxis of AMS. In our experience, prophylaxis with the recommended doses of acetazolamide resulted in fewer AMS symptoms and seemed to confer a higher likelihood of successfully summiting each peak. We conclude that acetazolamide is an acceptable choice for AMS prevention along with a slow, controlled ascent and proper fitness, nutrition, clothing, and gear.

Epidural analgesia is a widely used method of pain control in the labor and delivery setting but is not without risks. We present a case of Horner's syndrome and trigeminal nerve palsy as a rare complication of epidural analgesia in an obstetric patient. Although reported in few instances in the anesthesia literature, awareness among providers in obstetrics is critical because this could be the first sign of a high sympathetic blockade resulting in potential maternal-fetal morbidity.

Multiple case series published in the peer-reviewed medical literature have demonstrated the safety and efficacy of right-sided stellate ganglion block (SGB) for the treatment of anxiety symptoms associated with posttraumatic stress disorder (PTSD). As this is a new indication for a well-established procedure, there is relatively little information available to assist clinicians in determining the utility of SGB for their patients. Presented are clinical guidelines to assist the provider with patient selection, patient education, and follow-up. Also described is a technique to perform SGB under ultrasound-guidance. Although additional rigorous clinical research is needed to further investigate SGB for the treatment of anxiety symptoms associated with PTSD, these guidelines can also assist clinical investigators in their participant selection, design, and conduct of future research as it pertains to this important topic.

The paper puts forth the thesis that the security challenges of the twenty-first century require the addition of National Missile Defense (NMD) to U.S. nuclear deterrence strategy. It discusses this issue with the help of an historical analogy that compares the U.S. decision to build NMD to the Athenian decision in 479 BC to build its Long Walls linking Athens and its major seaport. First, the paper defines the three elements of U.S. nuclear deterrence posture: retaliation, defense, and dissuasion. Then, the paper establishes the current state of those three elements. The elements of strategic deterrence are assessed to determine their suitability to deter twenty-first century threats. To do this, current threats are examined and compared to the deterrent elements. The assessment reveals that the deterrence elements cannot meet the new security challenges, and recommends a re-balancing of the elements. Adjusting this balance will incur risks, and those risks are explored. The discussion of risks focuses on both the policy and technical risks of the suggested changes. By the end of this paper it will hopefully be clear that U.S. nuclear deterrence policy should be modified with the addition of an active defense component to meet twenty-first century security challenges.

In both training and research contexts, we encounter a growing assortment of terms used in the discussion of delivery systems for preretirement education. This educational activity and its attendant language have proliferated to the extent that some sorting is needed for the student, trainer, personnel development officer, researcher, and teacher. An essential question asks how delivery concepts do really differ from each other, not simply with respect to technical options, but decidedly with attention to such substantial matters as understandings of the preretirement participant‐learner, definitions of purpose, and specifications of differential leader‐training needs. In the spirit of that question, this writing (1) offers a framework of seven methodologically distinct delivery concepts visible in preretirement education today, (2) suggests their distinguishing qualities in terms of methodological principles and leader‐training issues, and (3) illustrates the more influential concepts with examples of es...