Wilderness & Environmental Medicine最新文献

Objective: Brain dysfunction at high altitudes can be caused by both high altitude cerebral edema (HACE) and hyponatremic encephalopathy. Differentiating them is important for proper treatment but can be difficult. We present a case series of 11 patients with hyponatremic encephalopathy, all initially misdiagnosed as HACE, and we discuss key signs and symptoms that will help clinicians differentiate the 2 pathologies.

Methods: We compiled 11 cases of patients with severe hyponatremia who were diagnosed with HACE, verified through direct patient care or referral consultation.

Results: Patients included 5 males and 6 females aged 19 to 65 y, exercising between 2100 and 4300 m. Serum Na⁺ concentration ranged from 112 to 127 mmol·L^-1. Features included ataxia, confusion, and progression to coma without the hallmark imaging features of HACE. Clinically, the rapid progression of symptoms, moderate altitude, short duration of altitude exposure, and seizure activity suggested hyponatremia rather than HACE. All but 1 patient shared classic risk factors for exercise-associated hyponatremia: moderate to extreme exercise, rapid high volume (>5 L) fluid intake, clamminess, pallor, and nausea. Five patients suffered seizures, 4 used nonsteroidal anti-inflammatory medications, 4 had pulmonary edema, and 3 showed features of the syndrome of antidiuretic hormone secretion.

Conclusions: Severe hyponatremia should be considered in persons with encephalopathy at high altitudes. Although there is no established causal link between hypobaric hypoxia and hyponatremia, the potential for high altitude exposure to exacerbate exercise-associated hyponatremia warrants further investigation because the consequences of developing or misdiagnosing this process may be severe.

Introduction: In the United States, more than 11.5 million people participate in hunting. Deer hunters commonly use tree stands as tall as 8 m. Falls from tree stands can cause injury and even death. Previous studies have investigated the types of injuries sustained from tree stand falls, but few have investigated patient outcomes. This study investigated patient outcomes related to tree stand falls and analyzed injury types resulting from tree stand falls, and this paper discusses factors that may lead to tree stand falls.

Methods: This study used a retrospective chart review of patients at the same institution between January 1, 2012, and August 31, 2022. Patient information, injury type, fall height, and interventions were collected.

Results: A total of 38 patients were included in the study, 36 males (94.70%) and 2 females (5.30%). The average fall height from a tree stand was 4.22±1.62 m (13.86±5.30 ft). Of the 38 patients, 19 had sustained orthopedic injuries to their upper extremity, lower extremity, spine/pelvis, or multiple areas; the average fall height of this subgroup was 4.51±1.76 m (14.79±5.76 ft). Nonoperative management was the highest used intervention because 12 patients did not require surgery. Orthopedic surgery was used to treat 6 patients, and 1 patient had nonorthopedic surgery.

Conclusions: Although tree stand falls are rare, the injuries they cause can be fatal. Injury severity and outcome are determined by a multitude of factors. This study highlights the significance of these injuries and the importance of practicing safe guidelines while hunting.

Mohave rattlesnakes (Crotalus scutulatus) are known to inhabit the deserts of southwestern United States, with their territory extending into southern Mexico. Envenomation can impart dramatic local and systemic effects on the body, ranging from local skin necrosis to neurotoxicity, depending on the protein complex in the venom. Kounis syndrome, or allergic angina, is an allergic response to a specific insult that results in myocardial injury often in the form of coronary artery vasospasm but can include myocardial infarction and coronary stent thrombosis. To our knowledge, there have not been any reports associating C scutulatus envenomation with Kounis syndrome. We describe a patient who developed Kounis syndrome presenting as an allergic myocardial infarction following envenomation by a Mohave rattlesnake. A second unique feature of this patient's envenomation is that he experienced respiratory failure secondary to right hemidiaphragmatic paralysis. Severe neurotoxicity from Mohave rattlesnake bites in humans has been reported rarely in the literature.

Spaceflight poses many risks to human health. Toxic exposures from inadvertent release of vehicle or payload chemicals and materials used in the operations of spaceflight are unique among them. There is a need for identification and development of clinical protocols for the management of toxic exposures before, during, and after spaceflight, particularly for acute exposures, because these events are likely to occur in austere environments with limited resources. The need for publicly available protocols is gaining importance as commercial spaceflight operations advance, and future spaceflight missions will require independence from Earth. This paper reviews the publicly available literature on toxic exposures in spaceflight to inform the development of relevant clinical practice guidelines. We performed a focused literature review and identified significant aerospace toxicologic incidents, including fatalities, injuries, and near-miss events. Sources included NASA-published literature, NASA safety reviews, published case reports, and published review articles. Searches were performed using the NASA Technical Reports Server, Google Scholar, and PubMed, and we included all cases involving exposure or potential exposure to an agent that could cause acute toxicity in spaceflight missions. Thirty-four cases were identified involving agents that can cause acute toxic effects. The two most common agents identified in acute toxicologic exposures in spaceflight operations were hydrazine and ammonia. These incidents can help us identify high-risk exposures so that we can develop protocols for the detection and management of future toxic exposures.

Introduction -The National Aeronautics and Space Administration's (NASA's) transition from operations in low-Earth orbit to long-duration missions to the Moon and Mars necessitates the development of progressively Earth-independent medical operations (EIMO) to support crews and reduce overall mission risk. Previous work has defined and laid the foundation for EIMO, but further development of the concept is required to prepare for future exploration missions. Methods -NASA's Exploration Medical Capability element organized a series of 5 technical interchange meetings from 2023 to 2024, which included internal (NASA) and external subject-matter experts in human spaceflight, health technology, and austere medicine to create a framework for developing the technologies and procedures necessary to maintain human health and performance in a progressively Earth-independent fashion. Results -The EIMO technical interchange meetings provided a forum for a field of experts and stakeholders to better understand gaps between current approaches to medical care in low-Earth orbit and the innovations needed to maintain the health and performance of astronauts on long-duration deep-space missions. These discussions were recorded, analyzed, and collated into reports that can inform the maturation of EIMO concepts. Conclusions -Multidisciplinary input from experts with experience in human spaceflight, health technology, and austere medicine is critical when planning for long-duration exploration missions. Innovations such as probabilistic risk assessment tools, extended reality devices, and advanced clinical artificial intelligence capabilities have been identified as high-value targets that can enhance inflight medical autonomy while maintaining appropriate workload balance and crew safety. By further developing the EIMO paradigm, NASA aims to identify areas of future work, research, and collaboration to reduce overall risk on future human spaceflight missions into deep space.

Introduction: Although marine envenomations are a reason for consultation in tropical emergency departments, stonefish stings are particularly feared. Immediate management focuses on pain control, whereas late management addresses cutaneous complications. This study presents a new series and compares the management of these patients and their outcomes at our center over the past 20 years.

Methods: This study presents a new series of 53 patients treated between 2016 and 2020 at the South Hospital of the University Hospital Center of Réunion following a sting attributed to the stonefish. We compared this new series with a previous series of patients treated at the same center for the same reason between 2001 and 2005.

Results: The series are comparable. Regarding early management, the use of regional anesthesia was more frequent (47 vs 3.5%). Half the patients received a strong opioid. Prescription of nonsteroidal anti-inflammatory drugs and corticosteroids persisted. Exposure to a heat source remained common. Prophylactic antibiotics were prescribed more frequently (64 vs 35%) and more uniformly with amoxicillin/clavulanate. Regarding late management, the average duration of hospitalization decreased (1.8 vs 2.6 d). Cutaneous complications were less frequent (9 vs 25%). No patient managed with regional anesthesia presented cutaneous complications.

Conclusions: The management of patients in Réunion following Scorpaenidae stings has evolved over time. Regional anesthesia has become more widespread, and the prescription of probabilistic preventive antibiotic therapy is more homogeneous. These changes are associated with a shorter hospital stay and fewer cutaneous complications.

Neotropical otters Lontra annectens (Carnivora, Mustelidae) are widely distributed in Central and South America. Studies on the behavior of this species are rare, resulting in the fact that its ethology is one of the lesser known among the mustelids. The Neotropical otter is considered solitary and territorial but not aggressive, and it generally shows a shy and elusive behavior. Here we described the first two documented cases of attack by Neotropical otters on humans. The first occurred in Sacatepéquez, Guatemala, and the second, in La Guajira, Colombia. Respectively, adult female and male humans were injured with differences in the severity of the wounds, clinical course, and outcomes. We recommend further research on the agonistic behavior of Neotropical otters. A protocol for attention to injuries caused by Neotropical otters is suggested.

In this case report we describe evaluating a patient for a traumatic knee arthrotomy using ultrasound in a resource-limited medical clinic at the base of a ski area. A 23-y-old female presented with a laceration superior to the patella of the left leg. On examination, the wound tracked deep, and providers had concern for traumatic arthrotomy. Lacerations around the knee have the highest risk for traumatic arthrotomy of any joint. This risk is due to the joint capsule of the knee extending up to 12 cm proximally from the joint line of the knee, making suprapatellar lacerations a risk. Although surgical evaluation is the gold standard for diagnosing a traumatic arthrotomy, computed tomography scan has been shown to be more sensitive than the saline-load test for identifying open traumatic arthrotomies. However, computed tomography scan was not available at the ski area clinic, and the authors have found the saline-load test to be extremely painful for patients. In this case, a novel technique using ultrasound to visualize a sterile cotton swab being inserted into the wound until it contacted the knee's joint line successfully identified a traumatic arthrotomy in a proximal knee laceration. The patient was transferred to a trauma center, where she had a surgical washout of her left knee joint. In conclusion, providers should be aware of the risk of traumatic arthrotomy in wounds that are proximal/superior to the patella. In this case, an ultrasound was used to confirm that the wound entered the proximal knee joint.

Introduction: -A multifaceted approach to wilderness medicine education and training is necessary to provide a high-quality learning experience, often requiring innovative instructional techniques. Using volunteers to act as patients in medical education is a well-established practice that helps teach crucial skills. However, more is needed to know if there is potential knowledge acquisition through participation. This study examined the educational benefits for medical students serving as a simulated patient (SP), hypothesizing that these individuals will improve self-assessed knowledge and confidence and demonstrate improved performance of injury-management skills while participating in a medical education course.

Methods: -A descriptive feasibility pilot study was conducted with 10 SPs to assess knowledge and skill acquisition. Study participants were evaluated before and after participating as an SP in 2 scenarios involving hemorrhage control and wrist injury assessment and management, with a subjective confidence survey and an objective skill and knowledge demonstration, as measured by a critical action checklist.

Results: -The subjects all reported self-assessed knowledge improvement from the pre- to postintervention survey, with an average increase of 17 points. They also demonstrated improved objective skill and knowledge demonstration, with an average increase of 4.6 points for the wrist injury scenario and 2.5 points for the hemorrhage control scenario.

Conclusions: -This study demonstrated that volunteer medical students acting as SPs in a medical training course passively acquire knowledge and improve their medical skills and self-perceived confidence. The findings contribute to a broader understanding of medical education, suggesting that participating as SPs offers educational benefits. The results encourage consideration of simulated patient roles as a valuable adjunct to medical education, warranting further scholarly exploration to substantiate and expand on these preliminary findings.

Introduction: Augmented reality is a promising technology for enhancing remote medical assistance. It assists users by directly projecting the relevant virtual assistance in the real world at the right moment and at the right location. This modality is called colocalization but has not been validated in parabolic flights. Our hypothesis was that this modality is technically feasible in weightlessness and is superior to a paper checklist in assisting a caregiver during a simulated medical emergency.

Methods: During parabolic flight campaigns, we conducted an abdominal pain simulation scenario and sought to compare procedural assistances. Participants performed a basic medical examination using either classic cognitive aids (such as a paper checklist) or an augmented-reality device projecting visual co-localized (situated or embedded) assistance.

Results: Gravity variations induced technical difficulties in the nominal functioning of augmented-reality headsets due to the native accelerometers in these devices. Clinical data were not interpretable due to small sample size secondary to the technical difficulties encountered. Finally, an efficient and stable spatial tracking configuration was found during the last flight, offering future research perspectives.

Conclusions: Our study validated the first achievement of a stable co-localized assistance under gravity variation. The augmented-reality headset required an external tracking system based on surrounding infrared cameras and an in-flight calibration to recreate the virtual environment (spatial mapping) independently of gravity conditions. Further studies are needed to clinically validate the potential benefits of co-localized augmented reality for space medicine.