A Pathophysiological Approach for Selecting Medications to Treat Nociceptive and Neuropathic Pain in Servicemembers.

INTRODUCTION: The prevalence of chronic pain of service members (SMs) in the U.S. is estimated to be higher (roughly 31-44%) compared to that of civilian population (26%). This higher prevalence is likely due to the high physical demands related combat and training injuries that are not immediately resolved and worsen over time. Mental Health America reports that chronic pain can lead to other mental health conditions such as severe anxiety, depression, bipolar disorder, and post-traumatic stress disorder. Such mental health conditions can negatively affect job performance, reduce readiness for military duties, and often lead to patterns of misuse of opioid after SMs entering civilian life. The primary objective of this narrative review is to present a summarized guideline for the treatment of two types of pain that likely affect SMs, namely nociceptive somatic pain and neuropathic pain. This review focused on a stepwise approach starting with nonopioid interventions prior to opioid therapy. The secondary objective of this review is to elucidate the primary mechanisms of action and pathways associated with these two types of pain. METHODS: We followed the Scale for Assessment of Narrative Review Articles when transcribing this narrative review article to enhance the quality and brevity of this review. This Scale has 0.77% an intra-class coefficient of correlation, 95% confidence interval and 0.88 inter-rater reliability. We searched PubMed, Google Scholar, WorldCAT, and the Cochrane Library for the primary and secondary articles that targeted mechanisms of action, pathways, and pharmacological modalities for nociceptive somatic and neuropathic pain that were published from 2011 to 2022. We excluded articles related to pediatric, some specific pain conditions such as cancer-related pain, palliative care, end-of-life care, and articles that were not written in English language. For pharmacologic selection, we adopted the guidelines from the Policy for Implementation of a Comprehensive Policy on Pain Management by the Military Health Care system for the Fiscal Year 2021; the Clinical Practice Guidance for Opioid Therapy for Chronic Pain by the Department of Defense/Veterans Health Administration (2022); the (2021) Implementation of a Comprehensive Policy on Pain Management by the Military Health Care System; and the (2022) Guideline for Prescribing Opioids for Chronic Painby the Centers for Disease Control. DISCUSSION: From the knowledge of the mechanisms of action and pathways, we can be more likely to identify the causative origins of pain. As a result, we can correctly diagnose the type of pain, properly develop an efficient and personalized treatment plan, minimize adverse effects, and optimize clinical outcomes. The guideline, however, does not serve as a substitute for clinical judgment in patient-centered decision-making. Medication choices should be individualized judiciously based on the patient's comorbid conditions, available social and economic resources, and the patient's preferences to balance the benefits and risks associated with various pain medications and to achieve optimal pain relief and improve the patient's quality of life.

Flotation-Restricted Environmental Stimulation Technique: A Proposed Therapy for Improving Performance and Recovery in Special Forces Operators - A Narrative Review.

The flotation-restriction environmental stimulation technique (FR) may have utility as a recovery tool for improving performance in elite competitive athletes and Special Operations Forces Operators (SOs). Studies suggest that FR may ameliorate various neurophysiological disorders and improve performance in recreational and elite athletic populations. We sought to understand whether there is evidence to support the use of FR to enhance physiological and psychological performance parameters in the SO population and to provide postulations as to the mechanisms of action of FR therapy. We performed an online literary search of publications dating from 1982 to 2021 and identified 34 sources addressing the aims, depending on population and condition or conditions, being treated. The reported physiological and psychological benefits of FR range from immediate to lasting 4 months. Overall, eight to twelve FR treatment sessions of from 40 to 90 minutes each may provide variable long-term benefits. The associated synergistic benefits of FR may be attributed to its thermal, chemical, and mechanical effects but deserve further exploration. Based on the current evidence, FR may serve as an effective performance-recovery therapy for improving pain, sleep, and performance measures (e.g., marksmanship and physical performance) in trained, untrained, and healthy adults. Future research focusing on FR as a unimodal recovery intervention is warranted in a specialized group of SOs.

Physiological and Psychological Stressors Affecting Performance, Health, and Recovery in Special Forces Operators: Challenges and Solutions. A Scoping Review.

INTRODUCTION: Special Operations Forces (SOF) Operators (SOs) are exposed to high levels of physiological and cognitive stressors early in their career, starting with the rigors of training, combined with years of recurring deployments. Over time, these stressors may degrade SOs' performance, health, and recovery. OBJECTIVES: (1) To evaluate sources identifying and describing physiological and psychological stressors affecting performance, health, and recovery in SOs, and (2) to explore interventions and phenomena of interest, such as the biological mechanisms of overtraining syndrome (OTS). METHODS: This review followed the recommendations and methodology of the Joanna Briggs Institute and the Preferred Reporting Items for Systematic reviews and Meta-Analyses extension for Scoping Reviews (PRISMA-ScR) guidelines. A database search from December 1993 to December 2021 was performed in PubMed, the Cochrane Library, and the Defense Technical Information Center (DTIC). Potential articles were identified using search terms from their titles, abstracts, and full texts. Articles effectively addressing the review questions and objectives were eligible. RESULTS: After 19 articles were excluded for not meeting established inclusion criteria, a total of 92 full-text articles were assessed for eligibility. After the final analysis, 72 articles were included. CONCLUSIONS: Allostatic imbalance may occur when supra-maximal demands are prolonged and repeated. Without adequate recovery, health and performance may decline, leading to nonfunctional overreaching (NFO) and OTS, resulting in harmful psychological and hormonal disruptions. The recurring demands placed on SOs may result in a chronically high burden of physical and mental stress known as allostatic overload. Future investigation, especially in the purview of longitudinal implementation, health, and recovery monitoring, is necessary for the health and readiness of the SOF population.

Effect of Special Operations Training on Testosterone, Lean Body Mass, and Strength and the Potential for Therapeutic Testosterone Replacement: A Review of the Literature.

OBJECTIVE: Due to physical demands, Special Operations Forces (SOF) endure changes in body composition, work capacity, and endocrine function. These changes result in energy deficits and sleep deprivation, where sleep averaged 3 hours/ day, independently known to decrease testosterone levels. The use of exogenous testosterone shows increases in lean body mass (LBM) and muscle function in healthy males and reverses cachexia in diseased populations. Therefore, the review's primary purpose is to summarize and contrast literature in both SOF and nonmilitary personnel regarding the correlation between negative energy balance, sleep deprivation, and decreased testosterone. The secondary purpose summarizes the effects of exogenous testosterone therapy in healthy males as well as reversing the effects of muscle wasting diseases. METHODS: An online literary search from 1975 to 2015 identified 46 of 71 sources addressing both purposes, and data were summarized into tables providing mean observations. CONCLUSIONS: SOF training results in decreased testosterone (-6.3%), LBM (-4.6%), and strength (-11.7%), tied to energy deficits (-3,351 kcal/day) and sleep deprivation (3 hours/ day). Exogenous testosterone therapy increases LBM (6.2%), strength (7.9-14.8%), reverses cachexia (2.0%) and increases strength (12.7%) in those with chronic diseases. Therefore, testosterone supplementation in SOF may attenuate changes in body composition and muscle function during training and sustained Special Operations (SUSOPS).

Effects of a New Cooling Technology on Physical Performance in US Air Force Military Personnel.

INTRODUCTION: Heat-related illness is a critical factor for military personnel operating in hyperthermic environments. Heat illness can alter cognitive and physical performance during sustained operations missions. Therefore, the primary purpose of this investigation was to determine the effects of a novel cooling shirt on core body temperature in highly trained US Air Force personnel. METHODS: Twelve trained (at least 80th percentile for aerobic fitness according to the American College of Sports Medicine, at least 90% on the US Air Force fitness test), male Air Force participants (mean values: age, 25 ± 2.8 years; height, 178 ± 7.9cm; body weight 78 ± 9.6kg; maximal oxygen uptake, 57 ± 1.9mL/kg/ min; and body fat, 10% ± 0.03%) completed this study. Subjects performed a 70-minute weighted treadmill walking test and 10-minute, 22.7kg sandbag shuttle test under two conditions: (1) "loaded" (shirt with cooling inserts) and (2) "unloaded" (shirt with no cooling inserts). RESULTS: Core body temperature, exercise heart rate, capillary blood lactate, and ratings of perceived exertion were recorded. Core body temperature was lower (ρ = .001) during the 70-minute treadmill walking test in the loaded condition. Peak core temperature during the 70-minute walking test was also significantly lower (ρ = .038) in the loaded condition. CONCLUSION: This lightweight (471g), passive cooling technology offers multiple hours of sustained cooling and reduced core and peak body temperature during a 70-minute, 22.7kg weighted-vest walking test.

Comparison of Topical Hemostatic Agents in a Swine Model of Extremity Arterial Hemorrhage: BloodSTOP iX Battle Matrix vs. QuikClot Combat Gauze.

BloodSTOP iX Battle Matrix (BM) and QuikClot Combat Gauze (CG) have both been used to treat traumatic bleeding. The purpose of this study was to examine the efficacy and initial safety of both products in a swine extremity arterial hemorrhage model, which mimics combat injury. Swine (37.13 ± 0.56 kg, NBM = 11, NCG = 9) were anesthetized and splenectomized. We then isolated the femoral arteries and performed a 6 mm arteriotomy. After 45 s of free bleeding, either BM or CG was applied. Fluid resuscitation was provided to maintain a mean arterial pressure of 65 mmHg. Animals were observed for three hours or until death. Fluoroscopic angiography and wound stability challenge tests were performed on survivors. Tissue samples were collected for histologic examination. Stable hemostasis was achieved in 11/11 BM and 5/9 CG subjects, with recovery of mean arterial pressure and animal survival for three hours (p < 0.05, Odds Ratio (OR) = 18.82 (0.85-415.3)). Time to stable hemostasis was shorter for the BM-treated group (4.8 ± 2.5 min vs. 58 ± 20.1 min; Median = 2, Interquartile Range (IQR) = 0 min vs. Median = 60, IQR = 120 min; p < 0.05) and experienced longer total stable hemostasis (175.2 ± 2.5 min vs. 92.4 ± 29.9 min; Median = 178, IQR = 0 min vs. Median = 120, IQR = 178 min; p < 0.05). Post-treatment blood loss was lower with BM (9.5 ± 2.4 mL/kg, Median = 10.52, IQR = 13.63 mL/kg) compared to CG (29.9 ± 9.9 mL/kg, Median = 29.38, IQR = 62.44 mL/kg) (p = 0.2875). Standard BM products weighed less compared to CG (6.9 ± 0.03 g vs. 20.2 ± 0.4 g) (p < 0.05) and absorbed less blood (3.4 ± 0.8 g vs. 41.9 ± 12.3 g) (p < 0.05). Fluoroscopic angiography showed recanalization in 5/11 (BM) and 0/5 (CG) surviving animals (p = 0.07, OR = 9.3 (0.41-208.8)). The wound stability challenge test resulted in wound re-bleeding in 1/11 (BM) and 5/5 (CG) surviving animals (p < 0.05, OR = 0.013 (0.00045-0.375)). Histologic evidence indicated no wound site, distal limb or major organ damage in either group. BM is more effective and portable in treating arterial hemorrhage compared to CG. There was no histologic evidence of further damage in either group.

Continuous One-Arm Kettlebell Swing Training on Physiological Parameters in US Air Force Personnel: A Pilot Study.

BACKGROUND: The primary aim of this study was to investigate the effects of continuous one-arm kettlebell (KB) swing training on various US Air Force physical fitness testing components. Thirty trained male (n = 15) and female (n = 15) US Air Force (USAF) personnel volunteered and were sequentially assigned to one of three groups based on 1.5-mile run time: (1) KB one-arm swing training, (2) KB one-arm swing training plus highintensity running (KB + run), and (3) traditional USAF physical training (PT) according to Air Force Instruction 36-2905. METHODS: The following measurements were made before and after 10 weeks of training: 1.5-mile run, 1-minute maximal push-ups, 1-minute maximal situps, maximal grip strength, pro agility, vertical jump, 40-yard dash, bodyweight, and percent body fat. Subjects attended three supervised exercise sessions per week for 10 weeks. During each exercise session, all groups performed a 10-minute dynamic warm-up followed by either (1) 10 minutes of continuous KB swings, (2) 10 minutes of continuous kettlebell swings plus 10 minutes of high-intensity running, or (3) 20 minutes of moderate intensity running plus push-ups and sit-ups. Average and peak heart rate were recorded for each subject after all sessions. Paired t tests were conducted to detect changes from pretesting to posttesting within each group and analysis of variance was used to compare between-group variability (ρ ≤ .05). RESULTS: Twenty subjects completed the study. There were no statistically significant changes in 1.5-mile run time between or within groups. The 40- yard dash significantly improved within the KB swing (ρ ≤ .05) and KB + run group (ρ ≤ .05); however, there were no significant differences in the traditional PT group (ρ ≤ .05) or between groups. Maximal push-ups significantly improved in the KB + run group (ρ ≤ .05) and trends toward significant improvements in maximal push-ups were found in both the KB (ρ = .057) and traditional PT (ρ = .067) groups. CONCLUSIONS: This study suggests that continuous KB swing training may be used by airmen as a high-intensity, low-impact alternative to traditional USAF PT to maintain aerobic fitness and improve speed and maximal push-ups.

Mitigating Exertional Heat Illness in Military Personnel: The Science Behind a Rice-Based Electrolyte and Rehydration Drink.

BACKGROUND: Exertional heat illness continues to be prevalent among members of active duty personnel, especially those in specific military occupational specialties such as loadmasters, flight crew, flight maintainers, and Special Operations Forces. Therefore, the primary objective of this article was to elucidate the various oral rehydration solutions (ORSs) on the market that are used to mitigate exertional heat illness (EHI) in military personnel, and to focus on the science behind a ricebased electrolyte drink, CeraSport®, currently used by US military personnel in mitigating EHI during sustained training operations in high-heat environments. METHODS: A search of the literature (through March 2016) was performed using PubMed and ProQuest, in addition to searching bibliographies and text books. We reviewed 63 articles and three texts. Articles were limited to those published in English and to studies that used only carbohydrates (e.g., no amino acids) and drinks reported to be used by the military in field training and deployment. CONCLUSION: Heat illness is prevalent among military personnel operating in high-heat environments and a variety of ORSs and sports drinks are available to help mitigate this. However, CeraSport, compared with other ORSs and sports drinks, may offer benefits such as faster gastric emptying rates and improved absorption from the gastrointestinal tract, which can provide rapidly available carbohydrate substrates for energy needs, and increased water retention for maintenance of blood plasma volume.

The use of dexamethasone in support of high-altitude ground operations and physical performance: review of the literature.

OBJECTIVE: Military Special Operators (SOs) are exposed environmental conditions that can alter judgment and physical performance: uneven terrain, dryness of ambient air, reduction of air density, and a diminished partial pressure of oxygen. The primary purpose of this review was to determine the medical efficacy of dexamethasone as an intervention for the prevention and treatment of high-altitude illness. The secondary purpose was to determine its ability to maintain physical performance of SOs at high altitudes. METHODS: A search of the literature from 1970 to 2014 was performed, locating 61 relevant articles, with 43 addressing the primary and secondary purposes of this literature review. CONCLUSIONS: The review indicates that dexamethasone is an effective prevention and treatment intervention for high-altitude illness. Commonly used dosages of either 2 mg every 6 hours or 4 mg every 12 hours can prevent high-altitude illnesses in adults. Currently in USSOCOM operations, there is an option to use 4 mg every 6 hours (concurrently with acetazolamide 125 mg bid) if ascending rapidly to or above 11,500 ft without time for acclimatization. Researchers also determined that acute exposure to high altitude, even in asymptomatic subjects, resulted in small cognitive deficits that could be reversed with dexamethasone. Dexamethasone may also help improve cognition and maximal aerobic capacity in SOs who are susceptible to high-altitude pulmonary edema.

Operational stressors on physical performance in special operators and countermeasures to improve performance: a review of the literature.

OBJECTIVE: Military training in elite warfighters (e.g., U.S. Army Rangers, Navy SEALs, and U.S. Air Force Battlefield Airmen) is challenging and requires mental and physical capabilities that are akin to that of professional athletes. However, unlike professional athletes, the competitive arena is the battlefield, with winning and losing replaced by either life or death. The rigors of both physical training and prolonged deployments without adequate rest and food intake can compromise physical performance. Therefore, the primary purpose of this effort was to identify occupational stressors on the physical performance of Special Operators during training and while on missions. The secondary purpose was to suggest specific countermeasures to reduce or prevent significant decrements in physical performance and reduce musculoskeletal injuries. METHODS: A search of the literature for 2000?2012 was performed using the Air Force Institute of Technology search engines (i.e., PubMed and ProQuest). There were 29 articles located and selected that specifically addressed the primary and secondary purposes of this literature review. The remaining 32 of 61 referenced articles were reviewed after initial review of the primary literature. CONCLUSIONS: This review indicates that operational stress (e.g., negative energy balance, high-energy expenditure, sleep deprivation, environmental extremes, heavy load carriage, etc.) associated with rigorous training and sustained operations negatively affects hormonal levels, lean muscle mass, and physical performance of Special Operators. The number of musculoskeletal injuries also increases as a result of these stressors. Commanders may use simple field tests to assess physical decrements before and during deployment to effectively plan for missions. Specific countermeasures for these known decrements are lacking in the scientific literature. Therefore, future researchers should focus on studying specific physical training programs, equipment, and other methods to minimize the effects of operational stress and reduce recovery time. These countermeasures could prevent mission mishaps and may save the lives of Special Operators during severe operational stress.

The influence of nontraditional training modalities on physical performance: review of the literature.

The primary purpose of this effort was to review several forms of nontraditional (NT) training programs, including heavy lower extremity strength training, CrossFit training, kettlebell training, and agility training, and discuss the effects of these exercise regimens on physical performance. The secondary purpose was to evaluate NT fitness training programs for evidence that they may provide beneficial options to help airmen improve their fitness scores. A search of the literature for 1980-2010 was performed using the Franzello Aeromedical Library, Public Medicine, and Air Force Institute of Technology search engines. There were 50 articles located and the authors selected 29 articles that specifically addressed the primary and secondary purposes of this literature review. This review indicates that an NT training approach is warranted in the general Air Force population. Heavy leg strength training and agility training show promise in enhancing aerobic fitness and improving fitness scores, particularly among members who have difficulty passing a physical fitness test. Most of the nontraditional forms of physical training are not supported in the scientific literature, with the exception of heavy leg strength training and agility training. However, even these NT forms of training require further investigation.

A novel cryotherapy compression wrap in the management of acute ankle sprains: potential use for special operators on the battlefield.

OBJECTIVE: Musculoskeletal injuries related to training and operational missions frequently affect military personnel. A common treatment for these injuries is the PRICE (protection, rest, ice, compression, and elevation) method, which is time consuming and impractical in the field. Therefore, the primary objective of this study was to determine the effectiveness of the cryotherapy wrap compared to a traditional treatment in the management of acute ankle sprains. METHODS: A randomized controlled clinical trial was conducted in a university research laboratory with 13 subjects (9 males and 4 females) with the following physical characteristics: age (yr) 20.6 ? 2.2, height (cm) 177.0 ? 14.3, weight (kg) 76.6 ? 20.6, and body mass index (kg/m2) 24.1 ? 3.7. Participants were instructed to perform PRICE with a traditional ice pack and compression wrap (control group) or with an Arctic Ease? cryotherapy wrap (test group) for 48 hours following enrollment in the study. The Numeric Pain Scale, Foot and Ankle Ability Measure, and ankle/foot volumetric measurement were performed at initial presentation and 24-hour, 48-hour, and 7-day follow-up intervals. RESULTS: While the comparison of the Numeric Pain Scale scores, Foot and Ankle Ability Measure scores, and volumetric changes between groups revealed no statistically significant differences (p > 0.01), there was an 86% compliance rate for subjects in the cryotherapy wrap group compared to a 17% compliance rate of subjects in the control group. CONCLUSIONS: The cryotherapy wraps performed comparably to ice therapy and therefore may be especially applicable to military personnel required to operate in austere and hostile environments where traditional therapies are unrealistic. Although this pilot study did not demonstrate that the cryotherapy wraps produce statistically superior results, trends emerged in the data suggesting that subject compliance rate may be improved by using an alternative form of cryotherapy compression, which could lead to better management of pain, edema, and functional recovery. Future research should include a larger sample size to verify this claim.

Current and future cooling technologies used in preventing heat illness and improving work capacity for battlefield soldiers: review of the literature.

OBJECTIVE: The goals were to review the effectiveness of current cooling technologies used on the battlefield to reduce or to prevent heat illness in soldiers and to discuss possible alternative or improved cooling methods. METHODS: A search of the literature for 1990-2007 was performed by using the Air Force Institute of Technology and Air Force Research Laboratory search engines. RESULTS: Several current cooling technologies are modestly effective in attenuating brain and core body temperatures, but the cooling effects are not sustained and the devices present operational problems. This review indicates that some current cooling devices are effective in lowering perceived efforts and lengthening maximal exercise time but are incompatible with current demands. CONCLUSIONS: Many of the cooling methods and devices detailed in the literature are impractical for use in the field. Future research should focus on cooling technologies that are practical in the battlefield and have sustainable cooling effects.