Arterial gas embolism in a Special Forces combat dive student during free-swimming ascent training: A case study.

Free-swimming ascent is taught to military divers and submariners as a self-rescue technique in the event of an emergency or a planned covert surfacing technique. Although this technique is infrequently used, it is considered a high-risk training event due to the risk and subsequent high morbidity and mortality of pulmonary barotrauma from pulmonary over-inflation injury. This case study will illustrate an example of a pulmonary overinflation injury and arterial gas embolism in an Army Special Forces Combat Diver who had no violation of technique while conducting a 50 foot free-swimming ascent to training standards and under the supervision of experienced Dive Supervisors. Additionally, the issue of allowing such individuals to return to diving is discussed.

Association of Physical Domain Participation with POTFF Domains in Special Forces Operators.

BACKGROUND: The purpose of this study was to evaluate the effectiveness of the physical domain (PD) to improve performance in all the POTFF domains (physical, psychological, social/family, and spiritual) among Special Forces (SF) Operators. METHODS: This was a cross-sectional study of active SF Operators assigned to the United States Army Special Operations Command (USASOC). Recruitment began in October 2016. Testing began on 1 January 2017, and concluded on 28 February 2020. Participants completed physical testing, blood draws, and questionnaires to determine domain metrics. Means, medians, and proportions were compared by level of participation in the PD. RESULTS: A total of 231 Soldiers participated; n=63 in the control group, n=93 in the <4 days PD/week (PD <4) group, and n=66 in the >4 days PD/week (PD =4) group. The average age was 31 years (range 21-47 y). The average time in the Special Operations Forces (SOF) was 4 years (range 0-19 y). The PD =4 group showed significantly greater overall upper (p=.01) and lower (p=0) body strength, power (p=.01), and positive affect (p=.04). The PD =4 group also had significantly lower anxiety (p=.03), stress (p=.04), and depression (p=.02) than the control group. CONCLUSION: The PD and psychological domain metrics were most associated with PD participation. This finding is consistent with the goals of the PD, which are to increase physical and mental capabilities and decrease injury recovery time.

Effects of hyperbaric oxygen on symptoms and quality of life among service members with persistent postconcussion symptoms: a randomized clinical trial.

IMPORTANCE: Improvement has been anecdotally observed in patients with persistent postconcussion symptoms (PCS) after mild traumatic brain injury following treatment with hyperbaric oxygen (HBO). The effectiveness of HBO as an adjunctive treatment for PCS is unknown to date. OBJECTIVES: To compare the safety of and to estimate the efficacy for symptomatic outcomes from standard PCS care alone, care supplemented with HBO, or a sham procedure. DESIGN, SETTING, AND PARTICIPANTS: Multicenter, double-blind, sham-controlled clinical trial of 72 military service members with ongoing symptoms at least 4 months after mild traumatic brain injury enrolled at military hospitals in Colorado, North Carolina, California, and Georgia between April 26, 2011, and August 24, 2012. Assessments occurred before randomization, at the midpoint, and within 1 month after completing the interventions. INTERVENTIONS: Routine PCS care was provided in specialized clinics. In addition, participants were randomized 1:1:1 to 40 HBO sessions administered at 1.5 atmospheres absolute (ATA), 40 sham sessions consisting of room air at 1.2 ATA, or no supplemental chamber procedures. MAIN OUTCOMES AND MEASURES: The Rivermead Post-Concussion Symptoms Questionnaire (RPQ) served as the primary outcome measure. A change score of at least 2 points on the RPQ-3 subscale (range, 0-12) was defined as clinically significant. Change scores from baseline were calculated for the RPQ-3 and for the total RPQ. Secondary measures included additional patient-reported outcomes and automated neuropsychometric testing. RESULTS: On average, participants had sustained 3 lifetime mild traumatic brain injuries; the most recent occurred 23 months before enrollment. No differences were observed between groups for improvement of at least 2 points on the RPQ-3 subscale (25% in the no intervention group, 52% in the HBO group, and 33% in the sham group; P = .24). Compared with the no intervention group (mean change score, 0.5; 95% CI, -4.8 to 5.8; P = .91), both groups undergoing supplemental chamber procedures showed improvement in symptoms on the RPQ (mean change score, 5.4; 95% CI, -0.5 to 11.3; P = .008 in the HBO group and 7.0; 95% CI, 1.0-12.9; P = .02 in the sham group). No difference between the HBO group and the sham group was observed (P = .70). Chamber sessions were well tolerated. CONCLUSIONS AND RELEVANCE: Among service members with persistent PCS, HBO showed no benefits over sham compressions. Both intervention groups demonstrated improved outcomes compared with PCS care alone. This finding suggests that the observed improvements were not oxygen mediated but may reflect nonspecific improvements related to placebo effects. TRIAL REGISTRATION: clinicaltrials.gov Identifier: NCT01306968.