Search Results (41)

Background: Acute mountain sickness (AMS) is a prevalent and potentially life-threatening condition caused by rapid exposure to high-altitude hypoxia, affecting pulmonary and neurological functions. Tongqiao Jiuxin Oil (TQ), a traditional Chinese medicine formula composed of aromatic and resinous ingredients such as sandalwood, agarwood, frankincense, borneol, and musk, has been widely used in the treatment of cardiovascular and cerebrovascular disorders. Clinical observations suggest its potential efficacy against AMS, yet its pharmacological mechanisms remain poorly understood. Methods: The chemical profile of TQ was characterized using UHPLC-Q-Exactive Orbitrap HRMS. Network pharmacology was applied to predict the potential targets and pathways involved in AMS. A rat model of AMS was established by exposing animals to hypobaric hypoxia (~10% oxygen), simulating an altitude of approximately 5500 m. TQ was administered at varying doses. Physiological indices, oxidative stress markers (MDA, SOD, GSH), histopathological changes, and the expression of hypoxia- and apoptosis-related proteins (HIF-1α, VEGFA, EPO, Bax, Bcl-2, Caspase-3) in lung and brain tissues were assessed. Results: A total of 774 chemical constituents were identified from TQ. Network pharmacology predicted the involvement of multiple targets and pathways. TQ significantly improved arterial oxygenation and reduced histopathological damage in both lung and brain tissues. It enhanced antioxidant activity by elevating SOD and GSH levels and reducing MDA content. Mechanistically, TQ downregulated the expression of HIF-1α, VEGFA, EPO, and pro-apoptotic markers (Bax/Bcl-2 ratio, Caspase-3), while upregulated Bcl-2, the anti-apoptotic protein expression. Conclusions: TQ exerts protective effects against AMS-induced tissue injury by improving oxygen homeostasis, alleviating oxidative stress, and modulating hypoxia-related and apoptotic signaling pathways. This study provides pharmacological evidence supporting the potential of TQ as a promising candidate for AMS intervention, as well as the modern research method for multi-component traditional Chinese medicine. Full article

Hypoxia can adversely affect multiple organ systems. This study investigated the impact of intermittent hypoxia on serotonin levels and depression-like behaviors across distinct neuroanatomical regions. Sixteen adult female Wistar albino rats were divided into two groups: control (n = 8) and hypoxia (n = 8). The hypoxia group was exposed to a simulated altitude of 3000 for 5 h daily over 14 days. Behavioral assessments included locomotor activity (open field test) and depression-like behaviors (forced swimming test). Serotonin levels were quantified via ELISA in the prefrontal cortex, striatum, thalamus, hypothalamus, hippocampus, and serum. Intermittent hypoxia did not alter locomotor activity (p > 0.05) but significantly increased depression-like behavior (p < 0.05), accompanied by a pronounced reduction in swimming behavior (p < 0.0001), a marker associated with serotonergic function. Serotonin levels were significantly reduced in the prefrontal cortex (p < 0.005) and striatum (p < 0.05), while no changes were observed in other regions or serum (p > 0.05). These findings demonstrate that intermittent hypoxia induces depression-like behaviors and region-specific serotonin depletion, particularly in the prefrontal cortex and striatum. This underscores the need to evaluate hypoxia-related brain health implications in conditions such as sleep apnea and acute mountain sickness. Full article

Background/Objectives: Acetazolamide is widely used for acute mountain sickness (AMS) prophylaxis. Whilst generally safe, acute kidney injury (AKI) is a rare but serious adverse event. We present a case of anuric AKI following minimal exposure to acetazolamide, contributing to the limited literature on its nephrotoxicity at prophylactic doses. Methods: A 54-year-old previously healthy male ingested 250 mg/day of oral acetazolamide for two days. He developed acute anuria and lumbar pain. Diagnostic evaluation included laboratory tests, imaging, microbiological cultures, autoimmune panels, and diuretic response. No signs of infection, urinary tract obstruction, or systemic disease were found. Results: The patient met KDIGO 2012 criteria for stage 3 AKI, with peak serum creatinine of 10.6 mg/dL and metabolic acidosis. Imaging confirmed non-obstructive nephrolithiasis. Conservative treatment failed; intermittent hemodialysis was initiated. Renal function recovered rapidly, with the normalization of serum creatinine and urinary output by day 4. Conclusions: This case represents the lowest cumulative dose of acetazolamide reported to cause stage 3 AKI. The findings support a pathophysiological mechanism involving sulfonamide-induced crystalluria and intratubular obstruction. Physicians should consider acetazolamide in the differential diagnosis of AKI, even with short-term prophylactic use. Full article

Introduction: Rapid ascent to altitudes of over 5000 m above sea level are associated with dramatic changes in adaptive physiology. The effects of a gradual ascent on symptoms, oximetry, and heart rate are described and compared with the effects of a rapid ascent to the same altitude by a comparable cohort. Methods: A group of 13 individuals (six females) representing 10 countries from five continents ascended gradually from Lukla (2300 m) to Everest Base Camp (5300 m) in Nepal over an 8-day period, then descended over a further 4 days. All symptoms and medication were recorded, along with pulse oximetry (SpO₂) and heart rate (HR) every 500 m of ascent. The results were then compared with those obtained at equivalent altitudes using similar methodology from a fast ascent of Mount Kilimanjaro to an equivalent altitude by a comparable cohort over 4 days. Results: The gradual ascent group had a median age of 33 years (range 25–66), and all successfully completed the trek. No severe headache, vomiting, orthopnoea, or productive cough occurred, although minor nausea and mild headache were common. Baseline oximetry fell from a median of 96% (93–97%) to a median of 78% (53–86%) at 8 days but recovered to 94% (89–99%) inside 4 days. Corresponding HR rose from a baseline median of 72 bpm (57–85) to a median of 103 bpm (78–115) at 8 days, then recovered to 80 bpm (54–94) after 4 days. Neither age nor gender correlated with outcomes. Individually, HR correlated inversely with oximetry, but there was no group correlation between these two variables. By contrast, a more rapid 4-day ascent from the same starting height, with similar baseline values for HR and oximetry, to the same final altitude was associated with more severe headache, breathlessness, and vomiting. Fast ascent was associated with a significantly more marked reduction in oximetry to a median of 71% (52–76) and an increase in HR to a median of 110 bpm (88–140). The fast ascent group also required significantly more medication, rated their experience as less enjoyable, and had a 100% incidence of acute mountain sickness compared to 0% in the slow ascent group. Discussion: Oxygen desaturation and tachycardia are inevitable consequences of ascending above 5000 m, but the degree to which this occurs can be reduced by slowing ascent times and taking rest days every 1000 m of ascent. This practice is associated with fewer symptoms and greater safety, with less need for either prophylactic or therapeutic medication. Careful consideration should be given to rates of ascent when climbing to altitudes at or above 5000 m. Full article

Wilderness medicine is a rapidly evolving field and has benefited from expanded research efforts. Moreover, with an escalating occurrence of severe and cataclysmic global climatologic events, human illness arising from interaction with wilderness and recreational environments warrants increasing consideration. Within the last decade, the Wilderness Medical Society (WMS) has aggregated research findings and created guidelines on prevention measures and therapeutic options for acute altitude illness, frostbite injuries, and avalanche and non-avalanche snow burials. As new research emerges, some guidelines have been updated to reflect the most current and sound scientific conclusions. In this review, we have synthesized the evidence-based guidelines and have reviewed the quality of the guidelines according to the Appraisal of Guidelines for Research and Evaluation (AGREE) II framework. Further research efforts can expand the scope of evidence-based practice in travel medicine and ideally standardize the implementation of recommendations within both pre-travel and post-travel medical practices. Full article

The Qinghai–Tibet Plateau, famously known as the “Roof of the World”, has witnessed a surge in individuals traveling or working there. However, a considerable percentage of these individuals may suffer from acute mountain sickness (AMS), with high-altitude pulmonary edema (HAPE) being a severe and potentially life-threatening manifestation. HAPE disrupts the balance of intrapulmonary tissue fluid, resulting in severe lung function impairment. Current therapeutic interventions for HAPE have limitations and are accompanied by significant side effects. Aldose reductase (AR), a crucial enzyme in the polyol metabolic pathway, has been implicated in various diseases. In this study, we sought to explore the role of AR in HAPE. Utilizing both in vivo and in vitro models, we investigated the impact of AR on hypoxia-induced pulmonary edema, vascular pressure, inflammatory factors, and oxidative stress. Our findings revealed that AR knockdown mitigated hypoxia-induced pulmonary edema, decreased the expression of vascular pressure and inflammatory factors, and enhanced the expression related to oxidative stress. These results indicate that AR may serve as a potential therapeutic target for HAPE, offering a plausible pathological basis and novel drug targets for the prevention and treatment of this condition. Full article

A high-altitude, low-pressure hypoxic environment has severe effects on the health and work efficiency of its residents, and inadequate preventive measures and adaptive training may lead to the occurrence of AMS. Acute exposure to hypoxia conditions can have a less-favorable physiological effect on the human immune system. However, the regulation of the immune system in high-altitude environments is extremely complex and remains elusive. This study integrated system bioinformatics methods to screen for changes in immune cell subtypes and their associated targets. It also sought potential therapeutically effective natural compound candidates. The present study observed that monocytes, M1 macrophages and NK cells play a crucial role in the inflammatory response in AMS. IL15RA, CD5, TNFSF13B, IL21R, JAK2 and CXCR3 were identified as hub genes, and JAK2 was positively correlated with monocytes; TNFSF13B was positively correlated with NK cells. The natural compound monomers of jasminoidin and isoliquiritigenin exhibited good binding affinity with JAK2, while dicumarol and artemotil exhibited good binding affinity with TNFSF13B, and all are expected to become a potential therapeutic agents. Full article

High-altitude diseases, including acute mountain sickness (AMS), high-altitude cerebral edema (HACE), and high-altitude pulmonary edema (HAPE), are closely related to an individual’s ability to adapt to hypoxic environments. However, specific research in this field is relatively limited, and further biomarker research and clinical trials are needed to clarify the exact role and potential therapeutic applications of key genes in high-altitude diseases. This study focuses on the role of the STC1 gene in high-altitude diseases and explores its expression patterns in different types of cancer. By using gene expression data analysis and functional experiments, we identified STC1 as a key gene affecting the development of altitude sickness. In addition, we also conducted expression and mutation analysis on STC1 in various cancer samples and found significant differences in the expression of this gene in 13 types of malignant tumors, which is associated with the hypoxic state in the tumor microenvironment. In addition, STC1 is significantly associated with patient prognosis and influences tumor immunity by mediating six types of immune cells (CD8+T cells, CD4+T cells, neutrophils, macrophages, monocytes, and B cells) in the tumor microenvironment. The expression and diagnostic value of STC1 were confirmed through GEO datasets and qPCR testing, indicating consistency with the results of bioinformatics analysis. These results indicate that STC1 is not only an important factor in the adaptive response to high-altitude diseases but may also play a role in the adaptation of cancer to low-oxygen environments. Our research provides a new perspective and potential targets for the discovery of biomarkers for high-altitude diseases and cancer treatment. Full article

Acute mountain sickness (AMS) is a common ailment in high-altitude areas caused by the body’s inadequate adaptation to low-pressure, low-oxygen environments, leading to organ edema, oxidative stress, and impaired intestinal barrier function. The gastrointestinal tract, being the first to be affected by ischemia and hypoxia, is highly susceptible to injury. This study investigates the role of Lactobacillus delbrueckii subsp. bulgaricus in alleviating acute hypoxic-induced intestinal and tissue damage from the perspective of daily consumed lactic acid bacteria. An acute hypoxia mouse model was established to evaluate tissue injury, oxidative stress, inflammatory responses, and intestinal barrier function in various groups of mice. The results indicate that strain 4L3 significantly mitigated brain and lung edema caused by hypoxia, improved colonic tissue damage, and effectively increased the content of tight junction proteins in the ileum, reducing ileal permeability and alleviating mechanical barrier damage in the intestines due to acute hypoxia. Additionally, 4L3 helped to rebalance the intestinal microbiota. In summary, this study found that Lactobacillus delbrueckii subsp. bulgaricus strain 4L3 could alleviate acute intestinal damage caused by hypoxia, thereby reducing hypoxic stress. This suggests that probiotic lactic acid bacteria that exert beneficial effects in the intestines may alleviate acute injury under hypoxic conditions in mice, offering new insights for the prevention and treatment of AMS. Full article

Background: The illnesses associated with changes in barometric pressure can be classified into three types: acute mountain sickness, high-altitude pulmonary edema (HAPE), and high-altitude cerebral edema. HAPE is a rare form of pulmonary edema that occurs in susceptible individuals after arriving at altitudes over 2500 m above sea level (m). Only a few studies have reported classical HAPE among children with underlying cardiopulmonary comorbidities. In this study, we report two pediatric cases of classical HAPE that occurred immediately upon arriving at Abha city (with an average elevation of 2270 m above sea level). Notably, both patients possessed underlying chronic lung diseases, raising crucial questions about susceptibility factors and the early onset manifestations of HAPE. Case: Two pediatric cases of HAPE are presented. The first patient, with a medical history of repaired right congenital diaphragmatic hernia and subsequent right lung hypoplasia, developed HAPE following their ascent to a high altitude. The second patient, diagnosed with diffuse lung disease of unknown etiology, experienced HAPE after a rapid high-altitude ascent. Both patients resided in low-altitude areas prior to ascent. The initial emergency room assessment revealed that both patients had severe hypoxia with respiratory distress that mandated the initiation of respiratory support and 100% oxygen therapy. They required intensive care unit admission, improved after 5 days of hospitalization, and were sent home in good condition. Conclusion: HAPE is a complex, potentially life-threatening high-altitude illness with diverse clinical presentations and variable risk factors. This case report sheds light on a potential predisposition factor—pre-existing lung disease—in children experiencing severe HAPE. While further validation is crucial, this valuable insight opens doors for improved preventative strategies and informed medical decisions for children with pre-existing lung conditions traveling to high altitudes. Full article

Background: Physical activity at high-altitudes is increasingly widespread, both for tourist trekking and for the growing tendency to carry out sports and training activities at high-altitudes. Acute exposure to this hypobaric–hypoxic condition induces several complex adaptive mechanisms involving the cardiovascular, respiratory and endocrine systems. A lack of these adaptive mechanisms in microcirculation may cause the onset of symptoms of acute mountain sickness, a frequent disturbance after acute exposure at high altitudes. The aim of our study was to evaluate the microcirculatory adaptive mechanisms at different altitudes, from 1350 to 5050 m a.s.l., during a scientific expedition in the Himalayas. Methods: The main haematological parameters, blood viscosity and erythrocyte deformability were assessed at different altitudes on eight European lowlanders and on a group of eleven Nepalese highlanders. The microcirculation network was evaluated in vivo by conjunctival and periungual biomicroscopy. Results: Europeans showed a progressive and significant reduction of blood filterability and an increase of whole blood viscosity which correlate with the increase of altitude (p < 0.02). In the Nepalese highlanders, haemorheological changes were already present at their residence altitude, 3400 m a.s.l. (p < 0.001 vs. Europeans). With the increase in altitude, a massive interstitial oedema appeared in all participants, associated with erythrocyte aggregation phenomena and slowing of the flow rate in the microcirculation. Conclusions: High altitude causes important and significant microcirculatory adaptations. These changes in microcirculation induced by hypobaric–hypoxic conditions should be considered when planning training and physical activity at altitude. Full article

Point of care ultrasound (POCUS) of the optic nerve is easy to learn and has great diagnostic potential. Within emergency medicine, research has primarily focused on its use for the assessment of increased intracranial pressure, but many other applications exist, though the literature is heterogeneous and largely observational. This narrative review describes the principles of POCUS of the optic nerve including anatomy and scanning technique, as well as a summary of its best studied clinical applications of relevance in emergency medicine: increased intracranial pressure, idiopathic intracranial hypertension, optic neuritis, acute mountain sickness, and pediatric intracranial pressure assessment. In many of these applications, sonographic optic nerve sheath diameter (ONSD) has moderately high sensitivity and specificity, but the supporting studies are heterogeneous. Further studies should focus on standardization of the measurement of ONSD, establishment of consistent diagnostic thresholds for elevated intracranial pressure, and automation of ONSD measurement. Full article

We aim to explore if there is a relationship between acute mountain sickness (AMS) and the risk of psychiatric disorders in Taiwan by using the National Health Insurance Research Database for to the rare studies on this topic. We enrolled 127 patients with AMS, and 1270 controls matched for sex, age, monthly insured premiums, comorbidities, seasons for medical help, residences, urbanization level, levels of care, and index dates were chosen from 1 January 2000 to 31 December 2015. There were 49 patients with AMS and 140 controls developed psychiatric disorders within the 16-year follow-up. The Fine–Gray model analyzed that the patients with AMS were prone to have a greater risk for the development of psychiatric disorders with an adjusted sub-distribution hazard ratio (sHRs) of 10.384 (95% confidence interval [CI]: 7.267–14.838, p < 0.001) for psychiatric disorders. The AMS group was associated with anxiety disorders, depressive disorders, bipolar disorder, sleep disorders, posttraumatic stress disorder/acute stress disorder, psychotic disorder, and substance-related disorder (SRD). The relationship between anxiety, depression, sleep disorders, SRD, and AMS still persisted even after we excluded the psychiatric disorders within the first five years after AMS. There was an association between AMS and the rising risk of psychiatric disorders in the 16 years of long-term follow-up research. Full article

Background: High-altitude tourist trekking continues to grow in popularity on the Everest Trek in Nepal. We examined which pre-existing cardiovascular and health conditions these global trekkers had and what health issues they encountered during the trek, be it exacerbations of pre-existing conditions, or new acute ones. Method: Trekkers (n = 350) were recruited from guesthouses along the Everest Trek, mostly at Tengboche (3860 m). After completing a questionnaire on their health and travel preparation, they underwent a basic physical examination with an interview. Results: Almost half (45%) had pre-existing conditions, mostly orthopaedic and cardiovascular diseases. The average age was 42.7 years (range 18–76). The average BMI was 23.4 kg/m², but 21% were overweight. A third were smokers (30%), and 86% had at least one major cardiovascular risk factor. A quarter (25%) were suffering from manifest acute mountain sickness (AMS), and 72% had at least one symptom of AMS. Adequate pre-travel examination, consultation, and sufficient personal preparation were rarely found. In some cases, a distinct cardiovascular risk profile was assessed. Hypertensive patients showed moderately elevated blood pressure, and cholesterol levels were favourable in most cases. No cardiovascular emergencies were found, which was fortunate as timely, sufficient care was not available during the trek. Conclusion: The results of earlier studies in the Annapurna region should be revalidated. Every trekker to the Himalayas should consult a physician prior to departure, ideally a travel medicine specialist. Preventative measures and education on AMS warrant special attention. Travellers with heart disease or with a pronounced cardiovascular risk profile should be presented to an internal medicine professional. Travel plans must be adjusted individually, especially with respect to adequate acclimatisation time and no physical overloading. With these and other precautions, trekking at high altitudes is generally safe and possible, even with significant pre-existing health conditions. Trekking can lead to invaluable personal experiences. Since organized groups are limited in their flexibility to change their itinerary, individual trekking or guided tours in small groups should be preferred. Full article

Background: Trekking to high-altitude locations presents inherent health-related hazards, many of which can managed with specific first aid (FA) training. This study evaluates the trip preparation, FA knowledge, and FA self-assessment of trekkers (organized by tour operators vs. individually planned tours). Data obtained shall be used for specific FA trip preparation and management of emergencies en route for this population. Methods: A total of 366 trekkers on the Everest Base Camp Trek, Nepal, were interviewed using a questionnaire specifically designed to evaluate their FA knowledge and management of emergencies. Data evaluation was performed using descriptive statistics. Results: A total of 40.5% of trekkers experienced at least one medical incident during their trip, of which almost 50% were due to acute mountain sickness (AMS). There was more AMS in commercially organized groups than in individually planned ones (55% vs. 40%). For more than 50%, no medical care was available during their trip. A total of 80% could answer only 3/21 FA questions completely correctly. Only 1% showed adequate knowledge concerning FA strategies. A total of 70% were willing to enroll in an FA class specialized towards the needs of trekkers. Conclusions: The importance of high-altitude FA knowledge and trip preparation is widely underestimated. There is an unmet demand amongst trekkers for specific wilderness FA classes. Full article