An Observational Study of Patient Characteristics and Environmental Risk Factors of Stingray Envenomations in San Diego, California.

INTRODUCTION: Current literature on stingray envenomations focuses on the incidence, presentation, and complications of these injuries, with some studies providing such data for specific geographic locations. This is the first study to evaluate the influence of environmental factors and human characteristics on stingray envenomation patterns in San Diego, California. METHODS: Incident reports of injuries documented by the San Diego Fire-Rescue Department/Lifeguard Division (SDFR-LG) during 2017 were analyzed. Water temperature and tide height were populated based on date and time. Data was analyzed for associations between stingray injuries incidence and tide height, water temperature, time, month, age and sex of the injured person, and whether they were local. RESULTS: 1722 stingray injuries were reported to the SDFR-LG in 2017. Stingray injuries were associated with water temperature (p < 0.001), more frequently occurring between 18.8 °C and 19.5 °C. Most envenomations occurred at tide heights between 1.7 ft and 3.1 ft. Most victims were aged 20-29, and there were more males than females injured. Beaches separated from the greater ocean or with a reef bottom had a lower incidence. Stingray injuries were more frequent during summer months. More stingray envenomations were documented for out-of-town beachgoers. CONCLUSIONS: Beachgoers with certain characteristics had more reported stingray envenomations than others. Males, nonlocal beachgoers, and individuals in their twenties had more injuries than their counterparts. Stingray injuries were more common at water temperatures between 18.8 and 19.5 °C. These findings may lead to future research on the prevention of stingray injuries.

Nationwide Aquatic Envenomations Reported to US Poison Control Centers from 2011 to 2020.

INTRODUCTION: Aquatic envenomations are common injuries along the coastal United States that pose a public health risk and can cause significant morbidity. We examined aquatic envenomation exposures that were called in to poison control centers (PCC) in the United States from 2011 to 2020. METHODS: The Association of Poison Control Center's (AAPCC) National Poison Data System was queried for all aquatic envenomations reported during the 10 y period from January 1, 2011, to December 31, 2020. Data collected included date, exposure and geographic location, patient age and sex, signs and symptoms, management setting, treatments, and clinical outcome. Duplicated records, confirmed nonexposure, and reports not originating within the United States were excluded. RESULTS: There were 8517 human aquatic envenomations reported during the study period, 62% (5243) of whom were male; 56% (4264) of patients were 30 y or younger. There were an average of 852 calls per year, with 46% of calls occurring during June to August. California, Texas, and Florida had the highest number of envenomations during the study period. Fish (61%; 5159) and Cnidaria (30%; 2519) envenomations were the most common exposures. Overall, 37% (3151) of exposures were treated in healthcare facilities, with no deaths reported. CONCLUSIONS: The highest proportion of aquatic envenomations occurred among younger males (≤30 y) during the summer months. While rarely leading to major adverse events, aquatic envenomations were commonly reported injuries to PCC and occurred in all 50 states. Poison control centers continue to be real-time sources of information and data regarding aquatic envenomation trends.

Environmental Exposures and Risks During Pregnancy.

The Women in Wilderness Medicine Research Committee of the Wilderness Medical Society conducted a narrative review to address considerations for pregnant individuals in wilderness environments. There is limited evidence behind many opinion-based recommendations on the safety of various environmental exposures in pregnancy. The authors reviewed the literature for the best available evidence, including observational studies, case series, limited controlled trials, and extrapolation from physiological data, as well as evaluating expert consensus statements. The benefits of exposure to natural environments include better pregnancy outcomes and improved maternal mental and physical health. Risks are similar to nonpregnant individuals with the added risks associated with maternal-fetal physiology in wilderness environments and difficulties of evacuation. This narrative review discusses pregnancy-specific concerns in extreme environments, including high altitude, hypothermia, hyperthermia, lightning strikes, envenomations, and common outdoor exposures.

First-Trimester Pregnancy: Considerations for Wilderness and Remote Travel.

Women increasingly participate in outdoor activities in wilderness and remote environments. We performed a literature review to address diagnostic and therapeutic considerations during first-trimester pregnancy for remote multiday travel. Pretrip planning for pregnant patients traveling outside access to advanced medical care should include performing a transvaginal ultrasound to confirm pregnancy location and checking D rhesus status. We discuss the risk of potential travel-related infections and recommended vaccinations prior to departure based on destination. Immediate evacuation to definitive medical care is required for patients with a pregnancy of unknown location and vaginal bleeding. We propose algorithms for determining the need for evacuation and present therapeutic options for nausea and vomiting, urinary tract infections, and candidiasis in the field.

Tension pneumomediastinum from opioid inhalation.

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.

Comparison of Radiographic, Ultrasound, and Magnetic Resonance Imaging for the Detection of Retained Stingray Barb: A Cadaveric Study.

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.

Prehospital Acute ST-Elevation Myocardial Infarction Identification in San Diego: A Retrospective Analysis of the Effect of a New Software Algorithm.

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.

A Prospective Study of Stingray Injury and Envenomation Outcomes.

BACKGROUND: Stingray injuries result in thousands of emergency department visits annually. OBJECTIVES: This study aimed to assess the complication rate and outcome of field treatment with hot water immersion. METHODS: This was an on-site, prospective, observational study. Subjects were enrolled after having been stung by a stingray. A trained researcher obtained the following information: age, sex, health conditions and medications, and wound description. The efficacy of hot water immersion on pain was recorded. Patients were contacted on postinjury days 3, 7, and 14 for follow up. RESULTS: Twenty-two subjects were included. No obvious foreign bodies were observed in wounds. Ten subjects were treated with hot water immersion and povidone-iodine, 12 with hot water immersion alone. Ongoing symptoms or complications were noted at the 3-day follow-up in 6 of 22 subjects (27.3%). One subject was diagnosed with cellulitis on post-sting day 8 and was treated with antibiotics. Ongoing symptoms or complications were reported more commonly in patients treated with hot water and povidone-iodine compared with those treated with hot water alone (p = 0.056). There was a significant difference in wound size between those with and without ongoing symptoms at the 3-day follow-up (p = 0.0102). No wounds <1 cm developed any complications. Average duration of water immersion was 73.6 min (range 35-145 min). The mean pain score pretreatment was 7.36 and posttreatment was 2.18, with an average decrease of 5.18 (95% confidence interval 4.22-6.15). CONCLUSION: Stingray injuries responded well to hot water immersion for pain control. Skin and soft tissue infection was diagnosed in 1 of 22 patients (4.55%).

Prehospital mass casualty incident triage simulation builds knowledge and confidence in medical trainees.

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 participant's 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.

Change in grip strength, hang time, and knot tying speed after 24 hours of endurance rock climbing.

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.