Guidelines for return to duty (play) after heat illness: a military perspective.

Since Biblical times, heat injuries have been a major focus of military medical personnel. Heat illness accounts for considerable morbidity during recruit training and remains a common cause of preventable nontraumatic exertional death in the United States military. This brief report describes current regulations used by Army, Air Force, and Navy medical personnel to return active duty warfighters who are affected by a heat illness back to full duty. In addition, a description of the profile system used in evaluating the different body systems, and how it relates to military return to duty, are detailed. Current guidelines require clinical resolution, as well as a profile that that protects a soldier through repeated heat cycles, prior to returning to full duty. The Israeli Defense Force, in contrast, incorporates a heat tolerance test to return to duty those soldiers afflicted by heat stroke, which is briefly described. Future directions for U.S. military medicine are discussed.

On-field management of emergent and urgent extremity conditions.

Extremity injuries are common in many sporting events. Properly treating these injuries consists of initial evaluation to determine a presumptive diagnosis and provision of appropriate management to decrease the risk of long-term sequelae. Evaluation for and treatment of neurologic and vascular compromise should always occur in the field as expeditiously as possible, taking care not to make the injury worse. Radiographs may be impractical or unnecessary prior to reduction of many injuries. In general, in-line traction and reduction is usually safe and may alleviate complications. Following field treatment, appropriate splinting is necessary to relieve pain and prevent complications during transport. Proper field management and referral of extremity conditions provides the best primary opportunity to avoid complications.

Exertional heat injury and gene expression changes: a DNA microarray analysis study.

This study examined gene expression changes associated with exertional heat injury (EHI) in vivo and compared these changes to in vitro heat shock responses previously reported by our laboratory. Peripheral blood mononuclear cell (PBMC) RNA was obtained from four male Marine recruits (ages 17-19 yr) who presented with symptoms consistent with EHI, core temperatures ranging from 39.3 to 42.5 degrees C, and elevations in serum enzymes such as creatine kinase. Controls were age- and gender-matched Marines from whom samples were obtained before and several days after an intense field-training exercise in the heat ("The Crucible"). Expression analysis was performed on Affymetrix arrays (containing approximately 12,600 sequences) from pooled samples obtained at three times for EHI group (at presentation, 2-3 h after cooling, and 1-2 days later) and compared with control values (average signals from two chips representing pre- and post-Crucible samples). After post hoc filtering, the analysis identified 361 transcripts that had twofold or greater increases in expression at one or more of the time points assayed and 331 transcripts that had twofold or greater decreases in expression. The affected transcripts included sequences previously shown to be heat-shock responsive in PBMCs in vitro (including both heat shock proteins and non-heat shock proteins), a number of sequences whose changes in expression had not previously been noted as a result of in vitro heat shock in PBMCs (including several interferon-induced sequences), and several nonspecific stress response genes (including ubiquitin C and dual-specificity phosphatase-1). We conclude that EHI produces a broad stress response that is detectable in PBMCs and that heat stress per se can only account for some of the observed changes in transcript expression. The molecular evidence from these patients is thus consistent with the hypothesis that EHI can result from cumulative effects of multiple adverse interacting stimuli.

Postexercise protein supplementation improves health and muscle soreness during basic military training in Marine recruits.

Elevated postexercise amino acid availability has been demonstrated to enhance muscle protein synthesis acutely, but the long-term impact of postexercise protein supplementation on variables such as health, muscle soreness, and function are unclear. Healthy male US Marine recruits from six platoons (US Marine Corps Base, Parris Island, SC; n = 387; 18.9 +/- 0.1 yr, 74.7 +/- 1.1 kg, 13.8 +/- 0.4% body fat) were randomly assigned to three treatments within each platoon. Nutrients supplemented immediately postexercise during the 54-day basic training were either placebo (0 g carbohydrate, 0 g protein, 0 g fat), control (8, 0, 3), or protein supplement (8, 10, 3). Subjects and observers making measurements and data analysis were blinded to subject groupings. Compared with placebo and control groups, the protein-supplemented group had an average of 33% fewer total medical visits, 28% fewer visits due to bacterial/viral infections, 37% fewer visits due to muscle/joint problems, and 83% fewer visits due to heat exhaustion. Recruits experiencing heat exhaustion had greater body mass, lean, fat, and water losses. Muscle soreness immediately postexercise was reduced by protein supplementation vs. placebo and control groups on both days 34 and 54. Postexercise protein supplementation may not only enhance muscle protein deposition but it also has significant potential to positively impact health, muscle soreness, and tissue hydration during prolonged intense exercise training, suggesting a potential therapeutic approach for the prevention of health problems in severely stressed exercising populations.

Bacterial vaginosis in sexually experienced and non-sexually experienced young women entering the military.

OBJECTIVE: To estimate the prevalence of bacterial vaginosis by Nugent Gram stain criteria in a nonclinic national sample of young women entering recruit training; to examine clinical associations with bacterial vaginosis; and to evaluate the performance of a pH test card and Papanicolaou smear against Gram stain as screening tools for bacterial vaginosis. METHODS: A cross-sectional study of 1938 women was conducted. Self-collected vaginal swabs were applied to a colorimetric pH test card and a glass slide for Gram stain evaluation according to the Nugent criteria. Papanicolaou smears and samples for sexually transmitted diseases screening were collected during routine entry pelvic examinations. RESULTS: Bacterial vaginosis prevalence was 27%, with 28% in sexually experienced and 18% in non-sexually experienced women (P = .001). Bacterial vaginosis prevalence was 11% in Asian/Pacific Islanders, which was lower than in other nonwhite ethnic groups (P = .004). Clinically, bacterial vaginosis was directly related to multiple sexual partners (P = .026), self-report of vaginal discharge (P = .001), self-report of vaginal odor (P < .001), and concurrent Chlamydia trachomatis infection (P = .002), and inversely related to hormonal contraceptive use (P = .013). Vaginal discharge did not achieve statistical significance in multivariate analysis. Compared with the Nugent criteria, the sensitivities and specificities for bacterial vaginosis diagnosis were as follows: colorimetric pH test: 72% and 67%; Papanicolaou smear: 72% and 79%, respectively. CONCLUSION: Among these diverse young women, bacterial vaginosis occurs commonly in both sexually experienced and inexperienced young women and differs by race and ethnicity. The pH colorimetric test and Papanicolaou smear performed moderately well as screening tools for bacterial vaginosis. The inverse relationship of bacterial vaginosis with hormonal contraceptive use and its direct relationship with C. trachomatis need further study.

Comparing first-void urine specimens, self-collected vaginal swabs, and endocervical specimens to detect Chlamydia trachomatis and Neisseria gonorrhoeae by a nucleic acid amplification test.

We set out to determine the prevalences of Chlamydia trachomatis and Neisseria gonorrhoeae by ligase chain reaction as well as to determine the prevalence of Trichomonas vaginalis by culture in a large and diverse national sample of non-health-care-seeking young women entering the military; we also sought to compare the abilities of three different techniques of collecting specimens (first-void urine, self-collected vaginal swab, and clinician-collected endocervical swab) to identify a positive specimen. A cross-sectional sample of young women was voluntarily recruited; as a part of their routine entry pelvic examination visit, they completed a self-administered reproductive health questionnaire and provided first-void urine (used to detect C. trachomatis and N. gonorrhoeae) and self-collected vaginal swabs (used to detect C. trachomatis, N. gonorrhoeae, and T. vaginalis). The number of positive tests divided by the number of sexually active women screened by each sampling method determined the rates of prevalence. The rate of infection with any of the three sexually transmitted diseases (STDs) tested was 14.1%. The total positive rates for each STD (identified by >/=1 specimen) were the following: for C. trachomatis, 11.6%; N. gonorrhoeae, 2.4%; and T. vaginalis, 1.7%. The proportions of positives identified by specimen type were, for C. trachomatis and N. gonorrhoeae, respectively, endocervix, 65 and 40%; urine, 72 and 24%; and vagina, 81 and 72%. The proportions of positives when specimen results were combined were, for C. trachomatis and N. gonorrhoeae, respectively, cervix plus urine, 86 and 49%; cervix plus vagina, 91 and 93%; and vagina plus urine, 94 and 79%. We concluded that STDs were epidemic in this population. Self-collected vaginal swabs identified the highest number of positive test results among single specimens, with the combined cervix-vagina results identifying the highest number of positive results. Self-collected vaginal swab collections are a feasible alternative to cervical specimen collections in this population, and the use of multiple types of specimens increases the positive yield markedly.

Distribution and mitogen response of peripheral blood lymphocytes after exertional heat injury.

To determine whether immune disturbances during exertional heat injury (EHI) could be distinguished from those due to exercise (E), peripheral lymphocyte subset distributions and phytohemagglutinin-stimulated CD69 mitogen responses as discriminated by flow cytometry were studied in military recruits [18.7 +/- 0.3 (SE) yr old] training in warm weather. An E group (3 men and 3 women) ran 1.75-2 miles. During similar E, 11 recruits (10 men and 1 woman) presented with suspected EHI. EHI (40.4 +/- 0.3 degrees C) vs. E (38.6 +/- 0.2 degrees C) body temperature was significantly elevated (P < 0.05). Heat illness was largely classified as EHI, not heatstroke, because central nervous system manifestations were generally mild. Blood was collected at E completion or EHI onset (0 h) and 2 and 24 h later. At 0 h (EHI vs. E), suppressor, natural killer, and total lymphocyte counts were significantly elevated, helper and B lymphocyte counts remained similar, and the helper-to-suppressor ratio was significantly depressed. By 2 h, immune cell dynamics between groups were similar. From 0 to 24 h, T lymphocyte subsets revealed significantly reduced phytohemagglutinin responses (percent CD69 and mean CD69 fluorescent intensity) in EHI vs. E. Thus immune cell dynamics with EHI were distinguishable from E. Because heat stress as reported in exercise or heatstroke is associated with similar immune cell disturbances, these findings in EHI contributed to the suggestion that heat stress of varying severity shares a common pathophysiological process influencing the immune system.

Changes in stress fracture distribution and current treatment.

Stress fractures were originally recognized as a problem in the military. As more people undertake strenuous training, the distribution of stress fractures has changed. Some of the difficulties in the discussion of stress fractures are the lack of a consistent definition and the variable sensitivity and specificity of different radiographic techniques. The definition proposed here involves the development of clinical symptoms with a corresponding radiographic change. A high index of suspicion must be maintained to pursue the diagnosis; plain radiographs are often initially negative and may never show characteristic changes. For treatment purposes, stress fractures can be grouped into high-risk and low-risk groups. Low-risk groups can be treated similarly and usually with excellent results, whereas high-risk stress fractures require a more cautious and specific approach.