View clinical trials related to Altitude Sickness.
Filter by:The purpose of the current study is to evaluate the cerebral tissue oxygenation of Kyrgyz highlanders with high altitude pulmonary hypertension (HAPH) by performing a longitudinal cohort study. To this end, the investigators will invite the same highlanders who participated in the study in 2012 to undergo follow-up examinations in 2017, in order to allow comparisons of current results with baseline data from 2012.
The purpose of the current study is to evaluate the progression of right ventricular function and dimension in Kyrgyz highlanders with high altitude pulmonary hypertension (HAPH) by performing a cross sectional case-control study.
The purpose of the current study is to evaluate the right ventricular function during graded cycling on an ergometer by transthoracic echocardiography in Kyrgyz highlanders with high altitude pulmonary hypertension (HAPH) by performing a cross-sectional case-control study.
The purpose of the current study is to evaluate the clinical and physiologic course of Kyrgyz highlanders with high altitude pulmonary hypertension (HAPH) by performing a longitudinal cohort study. To this end, the investigators will invite the same highlanders who participated in the study in 2012 to undergo follow-up examinations in 2017, in order to allow comparisons of current results with baseline data from 2012.
This double blind randomized trial will compare ibuprofen to acetazolamide for the prevention of acute mountain sickness. These drugs have never been directly compared for efficacy. The study population is hikers who are ascending at their own rate under their own power in a true hiking environment at the White Mountain Research Station, Owen Valley Lab (OVL) and Bancroft Station (BAR), Bancroft Peak, White Mountain, California.
Not uncommonly, sports events take place or finish at high altitude, where physical and cognitive (e.g. decision-making, motor control) performance in hypoxia is determining the outcome of sports performance. With nutritional supplements growing in popularity in the athletic and non-athletic population, research is increasingly focussing on dietary constituents which can improve cognitive and exercise performance. Flavonoids, a subgroup of polyphenols, are a class of natural compounds found in the human diet and include subcategories of flavanols, flavonols, iso-flavones, flavones, and anthocyanidins. Intake of flavanols, found in grapes, tea, red wine, apples and especially cocoa, causes an nitric oxide (NO)-mediated vasodilatation and can improve peripheral and cerebral blood flow (CBF). For cocoa flavanol (CF), there is evidence that both long term and acute intake can improve cognitive function, with the quantity and bioavailability of the consumed CF highly influencing its beneficial effects and with higher doses eliciting greater effects on cognition. Increased CBF following acute and chronic (3 months) CF intake has been demonstrated in healthy young subjects. Moreover, cognitive performance and mood during sustained mental efforts are improved after acute CF intake in healthy subjects and CF intake can increase prefrontal oxygenation during cognitive tasks in well-trained athletes. Moreover, CF intake is not only associated with an improved blood flow, but it might also improve exercise performance following 2 weeks of dark chocolate intake. On top of that, CF is known to have anti-oxidant properties and 2 week CF intake has been associated with reduced oxidative-stress markers following exercise. In hypoxic conditions, arterial pressure of oxygen (PaO2) and arterial saturation of O2 (SaO2) are decreased, compromising tissue oxygen delivery. Since brain function and brain integrity are dependent on continuous oxygen supply, brain desaturation may result in an impaired cognitive function in hypoxia. The severity of the impairment is related to the extent of high altitude, with at 3000m (=14.3 % oxygen (O2); = 71% of oxygen available at sea level) psychomotor impairments being visible. Cerebral oxygenation, which can be measured by Near-infrared spectroscopy, is lowered in hypoxia. It remains unclear whether CF intake can influence cerebral oxygenation and perfusion in hypoxic conditions and whether CF intake could (partially) counteract hypoxia-induced cognitive impairments. Therefore, the first aim of this study was to investigate whether cognitive function and prefrontal oxygenation during a mental demanding task will be impaired by hypoxic conditions (3000m altitude; 14.3% O2) and whether these impairments can be partially restored by subchronic CF intake (7 days, 900 mg/day). Hypoxia also impairs physical performance. Hypoxia-induced reductions in cerebral oxygenation may favour central fatigue, i.e. the failure of the central nervous system to excite the motoneurons adequately, hence impairing exercise performance in hypoxic conditions. Since hypoxia also impairs oxygen delivery to muscle tissue, the decreased oxygen supply to and impaired oxidative energy production in the exercising muscle is a second factor negatively affecting exercise performance. Besides the aforementioned effects of altitude on O2 delivery, hypoxia also results in increased oxidative stress. Oxidative stress refers to the imbalance between prooxidant and antioxidant levels in favor of prooxidants in cells and tissues and can result from diminished antioxidant levels or increased production of reactive oxygen species. The latter can be induced by both exhaustive exercise and high altitude. Since oxidative stress can be counteracted by CF, we also aim to investigate how markers of oxidative stress can be affected by CF intake by exercise in hypoxia. Therefore, the second aim of this study was to investigate possible beneficial effects of CF intake on changes in cerebral and muscle vasoreactivity and oxidative stress during exercise in hypoxia and its implications on exercise performance.
The study will aim to describe and evaluate the effect of chronic beetroot juice supplementation on acute mountain sickness symptoms and exercise in a hypoxic environment. It is hypothesized that beetroot supplementation will decrease acute mountain sickness and increase exercise performance.
This study evaluates the safety and efficacy of the voluntary ventilatory response as prophylaxis for acute mountain sickness, measured by the Lake Louise Self-Report Score, comparing to a group using acetazolamide.
A randomized, double-blinded study administering budesonide, a medication to reduce inflammation in the lungs, to healthy volunteers to examine effects on altitude illness prevention by spending 18 hours overnight at 14,000 ft elevation.
The purpose of this piece of research is to assess the effect of altitude on the clinical evolution of ARDS. For this purpose, patients who live and receive care at sea level are compared with those who live and receive care at high altitudes. For reasons of convenience, a cut-point of 1500 meters above sea level was chosen. In addition to this, it will be sought to assess whether adjusting the cut-points for the severity categories of ARDS improves the ability to predict some adverse events, by comparison with unadjusted cut-points. The results of this research will probably be disruptive, and will provide the first information yet about the effect of altitude on ARDS; they will therefore be of great interest for the international scientific community and for the direct care of patients. A high bibliometric impact is to be expected.