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Showing 1-11 of 11 trials
NCT07431554
More and more people are engaging in sports in the mountains, including individuals with heart or lung diseases. At the same time, such diseases are becoming more common in Switzerland. At high altitude, less oxygen is available, which places stress on the body-particularly on the heart, which has to pump blood through the lungs. How the heart, especially the right ventricle, in people with past HAPE responds to this stress is still not well understood. Therefore, this study investigates how the heart responds to simulated altitudes of 2,500 m and 4,000 m, both at rest and during light physical activity in patients with past HAPE. The primary objective is to assess how right ventricular function changes under conditions of reduced oxygen availability. In addition, vital signs, changes in blood gases, oxygen levels in blood and tissue and shortness of breath are assessed. The "altitude" is simulated using a special gas mixture that participants inhale. Participants undergo three altitude conditions (490, 2,500, and 4,000 m above sea level). The order of the altitude conditions is assigned at random. The aim is to better understand how the right ventricle and other parameters respond to low-oxygen conditions and how affected patients can be better supported in the future.
NCT07431567
More and more people are engaging in sports in the mountains, including individuals with heart or lung diseases. At the same time, such diseases are becoming more common in Switzerland. At high altitude, less oxygen is available, which places stress on the body-particularly on the heart, which has to pump blood through the lungs. How the healthy heart, especially the right ventricle, responds to this stress is still not well understood. Therefore, this study investigates how the heart responds to simulated altitudes of 2,500 m and 4,000 m, both at rest and during light physical activity. The present investigation focuses on healthy individuals in order to establish a reference for future comparisons with patients suffering from cardiopulmonary diseases. The primary objective is to assess how right ventricular function changes under conditions of reduced oxygen availability. In addition, vital signs, changes in blood gases, oxygen levels in blood and tissue and shortness of breath are assessed. The "altitude" is simulated using a special gas mixture that participants inhale. Healthy participants undergo three altitude conditions (490, 2,500, and 4,000 m above sea level). The order of the altitude conditions is assigned at random. The aim is to better understand how the right ventricle and other parameters respond to low-oxygen conditions and how affected patients can be better supported in the future.
NCT07193771
This multicenter observational study will evaluate the association between geographic altitude, availability of critical care resources, and clinical outcomes in children with pediatric acute respiratory distress syndrome (PARDS). Data on demographics, physiology, and hospital structure will be collected from PICUs located at different altitudes worldwide. The study aims to identify gaps in PARDS management and provide recommendations adapted to diverse resource settings.
NCT05966714
In this study, the objective is to compare neonatal cerebral electrical activity within 3 days after birth across different altitude areas using amplitude-integrated electroencephalography (aEEG), and establish reference value for each altitude level.
NCT04751292
High blood pressure (BP) is one of the principal cardiovascular risk factors. While BP levels and hypertension prevalence are well characterized in many populations, information on BP and on cardiovascular risk profile in high altitude inhabitants is limited and frequently contradictory, especially in the large highland populations of South America. The information on the effects of permanent high altitude exposure on cardiovascular variables including BP may be relevant in the light of the known BP-increasing effect of acute exposure to high altitude hypoxia. This information may have practical implications for millions of people living at elevated altitudes in Asia, South America and Africa. The inconclusive epidemiological evidence on BP and cardiovascular risk in high altitude dwellers may be the result of several factors, among them: 1) confounding by genetic and socio-economic factors; 2) imperfect methods of BP evaluation, in particular lack of data on ambulatory and home BP (both methods considered superior to conventional clinic BP in the assessment of exposure to high BP). On this background, the general aim of the study is to compare blood pressure levels and cardiovascular risk profile among population-based samples of subjects residing in Peruvian communities living at different altitudes.
NCT05517044
The aim of this study is to investigate the effect of pre-acclimatization in a nitrogen tent at home, ventilated with a slightly increased nitrogen percentage, in preparation for an expedition at extreme altitude. Specifically, the current study aims to gather knowledge, whether pre-acclimatization, first, leads to improved capillary function during an expedition to extreme altitude, and second, affects incidence of altitude sickness and the likelihood of reaching the expedition destination without oxygen supplementation. The project will be carried out in two phases corresponding to two randomized controlled trials in healthy volunteers, who are participating in an expedition at extreme altitudes with or without pre-acclimatization.
NCT05603689
A ketogenic diet (KD) reduces daily carbohydrates (CHOs) ingestion by replacing most calories with fat. KD is of increasing interest among athletes because it may increase their maximal oxygen uptake (VO2max), the principal performance limitation at high altitudes. The investigators examined the tolerance of a 4-week isocaloric KD (ICKD) under simulated hypoxia and the possibility of evaluating ICKD performance benefits with a maximal graded exercise bike test under hypoxia and collected data on the effect of the diet on performance markers and arterial blood gases.
NCT03536455
Randomized, placebo controlled trial evaluating the effect of acetazolamide on maximal exercise performance in lowlanders older than 40 years travelling from 760 m to 3'100 m.
NCT03536429
Randomized, placebo controlled trial evaluating the effect of acetazolamide on postural control in lowlanders older than 40 years travelling from 760 m to 3'100 m.
NCT03368352
Low oxygen at altitude causes pauses in breathing during sleep, called central sleep apnea. Central sleep apnea causes repeated awakenings and poor sleep. Low oxygen itself and the induced oxidative stress can damage mental function which is likely worsened by poor sleep. Reduced mental function due to low oxygen can pose a serious danger to mountain climbers. However there is also mounting evidence that even in populations of people that live at high altitudes and are considered adapted, low oxygen contributes to reductions in learning and memory. Therefore there is a serious need for treatments which may improve sleep, control of breathing and mental function during low oxygen. Melatonin is a hormone produced in the brain during the night which regulates sleep patterns with strong antioxidant and anti-inflammatory properties. A study previously reported that melatonin taken 90 mins before bed at 4,300 m (14,200 ft) induced sleep earlier, reduced awakenings and improved mental performance the following day. However how melatonin caused these effects was not determined. Therefore this study aims to determine how melatonin effects control of breathing, sleep and mental performance during exposure to low oxygen.
NCT03707249
This study involved human volunteers undertaking a high-altitude expedition. It assessed changes in physiological parameters of relevance to high-altitude cardiopulmonary physiology. Participants included a subgroup of those taking part in an existing adventurous training expedition and were randomised in a 1:1 fashion to receive either intravenous iron or normal saline several weeks prior to departure. During the expedition, participants were investigated by means of transthoracic echocardiography, peripheral oxygen saturation measurement and heart rate monitoring and through the drawing of venous blood samples. Bloods were later analysed for markers of iron status.