Wilderness & Environmental Medicine最新文献

As the global population grows and access to remote environments expands, travel to high altitude destinations has become increasingly common, now attracting ∼100 million visitors annually. This trend coincides with a population that is increasingly medically complex, emphasizing the importance of understanding how preexisting medical conditions are influenced by ascent to high altitude. This narrative review summarizes the current evidence describing the physiologic and clinical implications of altitude exposure among individuals with chronic medical conditions. A comprehensive literature search was conducted across multiple databases and sources using inclusive keyword and phrase strategies related to high altitude and preexisting medical conditions. All relevant peer-reviewed studies, reviews, and consensus statements were reviewed to ensure a thorough synthesis of available data. The discussion is organized by body system, encompassing cardiovascular, pulmonary, neurologic, metabolic, hematologic, and other relevant conditions. Findings indicate that while many patients with stable, well-managed chronic illnesses can tolerate moderate or even high altitudes, those with advanced cardiopulmonary disease or cerebrovascular pathology face heightened risk and warrant individualized evaluation prior to ascent. This review provides practical, evidence-based guidance to clinicians, expedition planners, and emergency providers caring for high altitude travelers with preexisting conditions. Recommendations emphasize pretravel risk stratification, optimization of chronic disease control, and strategies to mitigate altitude-related complications, supporting safer and more informed participation in high altitude activities.

IntroductionUltramarathons are growing considerably in both popularity and distance. This study aimed to identify factors associated with performance and satisfaction in ultramarathons of 200 mi (322 km) or more.MethodsThis cross-sectional study surveyed ultramarathoners who recently competed in a 200+ mi (322+ km) race between June and September 2023. The survey assessed demographics, ultramarathon experience, training habits, sleep-related factors, sleep-related adverse events, and injuries. Logistic regression quantified associations between variables and race outcomes.ResultsA total of 117 participants (67% male; mean age 47.2 y) completed the survey. Median race distance was 217 mi (interquartile range [IQR]=203-314 mi); 349 km [IQR=327-505 km]). Median sleep during races was 5.63 h (IQR=3.25-15.75 h). The most common within-race sleep strategy was sleeping when exhausted (38%). Finishing in the top quartile was associated with being male (odds ratio [OR]=3.37, more than 3fold higher odds than females), lower body mass index (OR=0.85, 15% lower odds per body mass index unit increase), and sleeping <7 h the night before (OR=0.33, 67% lower odds vs ≥7 h). Higher Pittsburgh Sleep Quality Index score (OR=0.70, 30% lower odds per point) and Insomnia Severity Index scores (OR=0.80, 20% lower odds per point) were associated with reduced likelihood of exceeding performance expectations. Weekly alcohol consumption, compared with monthly or less, was associated with lower race satisfaction (OR=0.42, 58% lower odds).ConclusionsThis study identified several factors associated with performance and satisfaction in 200+ mi (322+ km) ultramarathons, highlighting prerace and race sleep as key modifiable factors for optimizing performance.

IntroductionPregnant individuals benefit both psychologically and physically by participating in outdoor activities.MethodsThe authors conducted a narrative review of the available literature to address unique pregnancy considerations for the wilderness adventurer. There is limited evidence behind many opinion-based recommendations on participation in wilderness activities in pregnancy.ResultsAs a result, remote or adventurous activities may be considered unsafe or restricted without significant medical literature to support these opinions. The authors reviewed the literature for the best available evidence, including observational studies, case series, limited controlled trials, and extrapolations from physiological data, as well as evaluating expert consensus statements.ConclusionThis narrative review discusses pregnancy-specific medical concerns related to participation in outdoor adventure activities.

IntroductionPulmonary B-lines can be seen on lung ultrasound (LUS) and indicate the presence of pulmonary edema, as is seen in high-altitude pulmonary edema (HAPE). While asymptomatic B-lines have been observed in high-altitude travelers without clinical HAPE, their prevalence and relationship to high-altitude physiology remain poorly understood. This study aims to characterize B-line development in high-altitude travelers and its relationship to physiologic changes.MethodsThis observational study investigated adult trekkers in Nepal's Khumbu Valley. An 8-point LUS was performed to obtain a B-line quantification score. Altitude (2610-5364 m), vital signs, and Lake Louise score (LLS) for acute mountain sickness (AMS) were also recorded. A subset of participants was followed longitudinally as they ascended. Regression analyses were performed to compare the B-line score with altitude, pulse oximetry (SpO2), and LLS.ResultsA total of 88 subjects were enrolled, and 21 of these were followed longitudinally. There was a significant positive correlation between altitude and B-line score (r = 0.18, p = .049) in the general population; however, this finding was not significant in the longitudinal group (r = 0.21, p = 0.13). B-line score was inversely correlated with resting SpO2 (r = -0.3, p = 0.0008). There was no significant relationship between B-line score and LLS (r = 0.14, p = 0.12).ConclusionsLUS B-line scores were higher with increases in altitude, and resting SpO2 decreased with higher B-line scores. B-line scores were not correlated with the development of symptoms of AMS. More research is needed to elucidate the clinical significance of these asymptomatic findings.

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.