[{"data":1,"prerenderedAt":-1},["ShallowReactive",2],{"health-studies-list:{\"conditionNormalized\":\"acute-mountain-sickness-ams\",\"overallStatus\":[\"RECRUITING\",\"AVAILABLE\",\"NOT_YET_RECRUITING\"],\"orderBy\":\"LastUpdateSubmitDate:desc\",\"size\":25,\"offset\":0}":3,"health-study-condition:acute-mountain-sickness-ams":28},{"pageToken":4,"total":5,"offset":6,"count":5,"results":7},null,2,0,[8,41],{"id":9,"slug":10,"hasResults":11,"nctId":12,"briefTitle":13,"officialTitle":14,"acronym":4,"eligibilityCriteria":15,"healthyVolunteers":16,"sex":17,"minAge":18,"maxAge":19,"enrollmentInfo":20,"targetDuration":4,"studyType":23,"phases":24,"briefSummary":26,"conditions":27,"keywords":4,"overallStatus":29,"whyStopped":4,"lastUpdateSubmitDate":30,"lastUpdatePostDateStruct":31,"startDateStruct":34,"completionDateStruct":36,"leadSponsor":38,"locationsCount":4},"100604373","efficacy-of-positive-expiratory-pressure-on-acute-mountain-sickness-100604373",false,"NCT07148674","Efficacy of Positive Expiratory Pressure on Acute Mountain Sickness","Efficacy of Positive Expiratory Pressure on Acute Mountain Sickness, a Pilot Crossover Trial at 6000 Meters","Inclusion Criteria:\n\n* Healthy volunteers without ongoing medical conditions\n* Over 18 years of age\n* Volunteers with the physical and technical skills necessary to undertake a mountaineering expedition on Mount Aconcagua, Argentina, and with previous experience at extreme altitudes\n\nExclusion Criteria:\n\n* Subjects with any ongoing medical conditions\n* Under 18 years of age\n* Subjects without previous mountaineering experience at extreme altitudes and without adequate physical and technical preparation necessary to undertake a mountaineering expedition on Mount Aconcagua, Argentina",true,"ALL","18 Years","99 Years",{"count":21,"type":22},3,"ESTIMATED","INTERVENTIONAL",[25],"NA","This pilot study aims to evaluate the efficacy of positive expiratory pressure (PEP) therapy at 10 cmH₂O in improving peripheral oxygen saturation (SpO₂) and mitigating symptoms of acute mountain sickness (AMS) in healthy individuals exposed to extreme altitude conditions.\n\nThree male participants will be monitored during an ascent of Mount Aconcagua, Argentina, at elevations of 4,300 m, 5,560 m, and 6,000 m above sea level. The study involves three sequential phases of 10 minutes each: baseline breathing without PEP, breathing with PEP applied via a mechanical face mask, and post-PEP breathing.\n\nPrimary outcomes include changes in SpO₂ and Lake Louise Score (LLS) to assess AMS severity. Findings will provide preliminary data on the potential role of PEP as a non-pharmacological intervention in high-altitude medicine.",[28],"Acute Mountain Sickness (AMS)","NOT_YET_RECRUITING","2025-08-28",{"date":32,"type":33},"2025-08-29","ACTUAL",{"date":35,"type":22},"2025-09-05",{"date":37,"type":22},"2025-12-31",{"name":39,"class":40},"BiALP - Alpine, Disaster and Wilderness Medicine","OTHER",{"id":42,"slug":43,"hasResults":11,"nctId":44,"briefTitle":45,"officialTitle":46,"acronym":4,"eligibilityCriteria":47,"healthyVolunteers":16,"sex":17,"minAge":18,"maxAge":48,"enrollmentInfo":49,"targetDuration":4,"studyType":23,"phases":51,"briefSummary":53,"conditions":54,"keywords":59,"overallStatus":66,"whyStopped":4,"lastUpdateSubmitDate":67,"lastUpdatePostDateStruct":68,"startDateStruct":70,"completionDateStruct":72,"leadSponsor":73,"locationsCount":75},"100602050","phase-4-highcycle-study-acetazolamide-high-altitude-and-plasma-volume-100602050","NCT07118462","HighCycle Study: Acetazolamide, High Altitude and Plasma Volume","HighCycle Study: Effect of Acetazolamide on Plasma Volume During Acute Exposure to High Altitude in Women and Men","Inclusion Criteria:\n\n* Healthy, non-smoking men and women, age 18-44 years, without any disease and need of regular medication (including oral contraceptives).\n* BMI \\>18 kg\u002Fm2 and \\\u003C30 kg\u002Fm2.\n* Born, raised and currently living at altitudes \\\u003C1000 m.\n* Written informed consent.\n* Premenopausal women with an eumenorrheic cycle.\n\nExclusion Criteria:\n\n* Other types of contraceptvies (contraceptives (hormonal intrauterine device, vaginal ring, subcutaneous injections or implants, among others).\n* Pregnancy or nursing\n* Anaemic (haemoglobin concentration \\\u003C10g\u002Fdl).\n* Any altitude trip \\\u003C4 weks before the study.\n* Allergy to acetazolamide and other sulfonamides.","44 Years",{"count":50,"type":22},270,[52],"PHASE4","Each year, millions of people living at low altitude (\\\u003C 1,000 m) travel to high altitude (≥ 2,500 m) for work, tourism, or sports activities. These individuals are exposed to hypobaric hypoxia, which can trigger acute mountain sickness (AMS)-the most common form of altitude-related illness. Therefore, understanding the physiological responses to hypoxia that allow acclimatization, as well as the pathophysiology of acute mountain sickness, is of primary importance.\n\nThe hematological response to high-altitude exposure initially includes a reduction in plasma volume (PV), leading to an early increase in hemoglobin concentration within the first 24 hours. In contrast, an increase in hemoglobin mass requires several weeks at high altitude. Recent well-controlled physiological studies conducted in hypobaric chambers have demonstrated that this hypoxia-induced PV contraction results from fluid redistribution from the intravascular to the extravascular compartment, rather than from water loss due to increased diuresis.\n\nProphylaxis of AMS is primarily based on the administration of 250 mg\u002Fday of acetazolamide (ACZ), a carbonic anhydrase inhibitor with a mild diuretic effect. Acetazolamide induces metabolic acidosis, which stimulates ventilation and thereby improves oxygenation. The effect of prophylactic ACZ use during high-altitude exposure on PV in lowlanders remains unknown: it is unclear whether ACZ leads to a greater reduction in PV due to its diuretic effect, or to a smaller hypoxia-induced PV contraction as a result of improved oxygenation induced by increased ventilation.",[55,56,28,57,58],"High Altitude Effects","High Altitude Hypoxia","Plasma Volume","Women",[60,61,62,63,64,65],"acetazolamide","plasma volume","acute mountain sickness","high altitude","hypoxia","women","RECRUITING","2025-08-11",{"date":69,"type":33},"2025-08-12",{"date":71,"type":33},"2024-07-15",{"date":37,"type":22},{"name":74,"class":40},"Centre d'Expertise sur l'Altitude EXALT",1]