BACKGROUND: Mass casualty incident (MCI) triage simulation is an increasingly useful tool for teaching triage systems to medical students, trainees, and hospital staff. MCI simulation in the prehospital setting has not yet been studied in this population. OBJECTIVES/AIMS: We aimed to assess the effectiveness of a prehospital MCI simulation in medical students, residents, and fellows. Our primary outcome was knowledge of the components of the triage algorithms used in MCI response. Our secondary outcome was each participants confidence level if required to assist with or lead a MCI response. METHODS: This was an observational study with pre-post surveys. We recruited 30 medical students, 14 emergency medicine (EM) residents, and four pediatric EM fellows to fill out a survey before and after a 3-h simulation session practicing the START and JumpSTART algorithms on two prehospital MCI scenarios. RESULTS: Overall, all groups demonstrated significant improvement in knowledge of triage colors, information needed to assign a triage color, pediatric airway management during a MCI, and indications for breaths-first CPR. They also demonstrated significant increase in confidence both in assisting with and in leading a MCI response. CONCLUSIONS: Simulated practice triaging patients in prehospital MCI scenarios improves knowledge of triage algorithms and increases confidence in assisting with or leading a MCI response in medical trainees.

To give a representative overview of medical professionals working in today's remote and extreme environments, we consider the following teams and organizations: Expeditions on 8000m peaks led by accredited guides of the American Mountain Guides Association (AMGA) or International Federation of Mountain Guides Association (IFMGA). Everest Base Camp Medical Clinic (Everest ER) in Nepal. US Antarctic Program (USAP). Medical Departments aboard US Navy ships and submarines. US Special Operations Command (SOCOM) Corpsmen and Medics. US Navy Diving Medical Officers. Crew Medical Officers (CMO's) aboard the International Space Station After reviewing the practice environments and medical training of the various teams, we consider the medical qualifications of a hypothetical future team embarking on a mission to a particularly remote and extreme environment, a human spaceflight mission to the surface of Mars.

Background: Non-professional climbers are increasingly attempting long routes in a single day. Many suffer injury or rely on search and rescue teams when they become too fatigued to finish. Predicting fatigue is difficult, and existing studies have only studied climbers over durations less than an hour, while many outdoor multipitch climbs require more than an hour of climbing. Objectives: To determine how strength, endurance, and dexterity reflect fatigue after 24 h of continuous climbing. Methods: Volunteer competitors completed measurements of grip strength, static hang time to failure, and time to tie a figure-eight follow-through knot. Measurements were taken during the registration period before the competition and again within an hour after the competition ended. Measurements were compared using the paired t-test. Subgroup analysis was applied to competitors by division. Linear regression was applied to determine the relationship between vertical feet climbed and the number of routes climbed during the competition on each metric. Results: Thirty-six total climbers (average age 29.4 years old) completed pre- and post-competition measurements. After 24 h of climbing (n = 36), mean grip strength decreased by 14.3–15 lbs or 14.7%–15.1% (p < 0.001) and static hang time decreased by 54.2 s or 71.2% (p < 0.001). There was no significant change in time to tie a figure-eight-follow-through knot. Grip strength and hang time decreases were significant in climbers with outdoor redpoints of 5.10a and above. Hang time decreased by 5.4 s per 1,000 vertical feet climbed (p = 0.044). Conclusion: Climbers can expect to experience a 14.7%–15.1% decrease in grip strength and 71.2% decrease in static hang time after 24 h of continuous climbing. These changes may make it difficult to climb consistently over a long objective, and climbers can use these measures at home to train for longer climbing routes. Future studies on shorter climbing intervals can help determine rates of decline in performance measures.

BACKGROUND:A significant increase in false positive ST-elevation myocardial infarction (STEMI) electrocardiogram interpretations was noted after replacement of all of the City of San Diego's 110 monitor-defibrillator units with a new brand. These concerns were brought to the manufacturer and a revised interpretive algorithm was implemented. OBJECTIVES:This study evaluated the effects of a revised interpretation algorithm to identify STEMI when used by San Diego paramedics. METHODS:Data were reviewed 6 months before and 6 months after the introduction of a revised interpretation algorithm. True-positive and false-positive interpretations were identified. Factors contributing to an incorrect interpretation were assessed and patient demographics were collected. RESULTS:A total of 372 (234 preimplementation, 138 postimplementation) cases met inclusion criteria. There was a significant reduction in false positive STEMI (150 preimplementation, 40 postimplementation; p < 0.001) after implementation. The most common factors resulting in false positive before implementation were right bundle branch block, left bundle branch block, and atrial fibrillation. The new algorithm corrected for these misinterpretations with most postimplementation false positives attributed to benign early repolarization and poor data quality. Subsequent follow-up at 10 months showed maintenance of the observed reduction in false positives. CONCLUSIONS:This study shows that introducing a revised 12-lead interpretive algorithm resulted in a significant reduction in the number of false positive STEMI electrocardiogram interpretations in a large urban emergency medical services system. Rigorous testing and standardization of new interpretative software is recommended before introduction into a clinical setting to prevent issues resulting from inappropriate cardiac catheterization laboratory activations.

Pneumomediastinum is a rare complication of substance use, likely due to a Valsalva maneuver after drug inhalation. There are no previously documented associations between pneumomediastinum and opioid use. A 30-year-old man with a history of recent heroin and fentanyl inhalation presented to the emergency department in respiratory distress requiring intubation. His course was complicated by pneumomediastinum which subsequently developed tension physiology. He required emergent surgical decompression with a "blowhole incision" to his anterior chest. Although a rare complication of polysubstance use, pneumomediastinum can progress to tension physiology, requiring prompt diagnosis and management.

Introduction

Stingray envenomations are a common marine animal injury for which it is important to identify and remove retained barbs to prevent secondary infection. The optimal imaging modality in stingray foreign body detection is not well characterized in the existing literature. In this study, we compared the accuracy of plain radiography, ultrasound, and magnetic resonance imaging (MRI) in detecting stingray barbs in the human foot and ankle.

Methods

This cadaveric study included a 1:1 randomization to the presence or absence of barbs in 24 sample injuries of human cadaveric foot and ankle specimens. Physicians trained in emergency medicine and radiology performed ultrasound examinations on each specimen and interpreted the presence or absence of a barb. Participants also interpreted x-ray images in the same manner. MRI scans were separately interpreted by a musculoskeletal radiology attending. Data were analyzed using McNemar's test.

Results

The 19 participants included 14 (74%) trained in emergency medicine and 5 (26%) trained in radiology. Forty-seven percent were residents, 42% faculty, and 11% fellows. X-ray was associated with the highest sensitivity of 94% for the identification of a retained barb, followed by MRI (83%) and ultrasound (70%). MRI was associated with the highest specificity of 100%, followed by x-ray (98%) and ultrasound (73%).

Conclusions

Retained stingray barbs can lead to secondary infection after envenomation. In human cadaveric specimens, x-ray demonstrated the highest sensitivity, MRI demonstrated the highest specificity, and ultrasound demonstrated lower sensitivity and specificity.