View clinical trials related to Altitude.
Filter by:Sleep at altitude is often poor. The purpose of this study is to evaluate the effects of a single dose of the opioid antagonist, naltrexone, on sleep quality and periodic breathing after rapid ascent to ~3800m altitude.
The aim of this study is to compare the psychophysiological effects of terrestrial altitude with a normobaric, hypoxic situation.
The degree to which endurance exercise performance is diminished in acute hypoxia is variable and appears to be the result of several different physiological processes, however this research focuses on hypoxic pulmonary vasoconstriction (HPV). Sildenafil, a pulmonary vasodilator, has been used with mixed results to improve athletic performance in hypoxia. Because sildenafil has been shown to reduce HPV in some individuals, we believe that its effectiveness is closely related to the magnitude of the HPV response and the degree that individual exercise performance declines in hypoxia. This research will investigate the relationship between sildenafil, HPV, and exercise performance.
Important advances in cardiac surgery, intensive care, and diagnostic modalities over the last decades have led to a steady growth in the number of adults with congenital heart defects. Among adults with congenital heart disease, patients with a Fontan circulation typically show the lowest values of peak oxygen consumption. For these patients, strict exclusion from activities at high altitude may have an impact on quality of life. The investigators aim to elucidate the short term effects of a stay at high altitude on hemodynamic adaptation, exercise capacity and clinical well being in adult Fontan patients. The investigators hypothesize that patients with a Fontan circulation in NYHA functional class I-II are able to increase their cardiac output during exercise at high altitude in order to meet the required metabolic demands and therefore tolerate the journey to the Jungfraujoch well.
Tuebingen High Altitude Ophthalmology Study to investigate the effects of high altitude on retinal structure and function as well as anterior chamber in regard to acute mountain sickness.
Exposure of healthy subjects to high altitude hypoxia elicits changes in cardiovascular, respiratory and metabolic features as weel as in exercise performance similar, for some aspects, to those observed in chronic heart failure. Exposure to high altitude hypoxia represents a suitable model to assess different treatments proposed for this pathological condition. Our aim was to evaluate the impact of two different third-generation beta-blockers used in heart failure (carvedilol and nebivolol) on cardiovascular, respiratory, metabolic profile and on exercise performance at high altitude.
With the increasing tourism and adventure travel into extreme environments comes the need to reassess the required protection against ultraviolet (UV) radiation and possible other oxidative stresses. This is an observational study of UV radiation exposure and skin erythema while at extreme altitude (Mt. Everest). In addition to UV exposure, skin erythema, antioxidant use (such as vitamins C and E) will be measured. Hypothesis: 1. UV radiation at extreme altitude has larger effects on the skin than at sea level; therefore requiring an adjustment of the antioxidant use for adequate protection. 2. The skin is an accurate reflection of UV and oxidative stress exposure 3. The efficacy of oxidatives stress is reflective of the ethnicity of the individual.
Hypobaric hypoxia (decreased oxygen supply to body tissues due to low atmospheric pressure) caused by exposure to high altitude disrupts sleep. Sleep deprivation is associated with degraded post-sleep performance of neurobehavioral tasks. The lowest altitude at which sleep and/or post-sleep performance are affected is not known. The study hypothesis is that sleep and/or post-sleep performance of neurobehavioral tasks will occur due to hypobaric hypoxia at altitudes of 8,000 or less.
This study is to determine whether bosentan will alter exercise capacity after rapid ascent to high altitude. We hypothesize that bosentan administration will improve arterial oxygenation and exercise capacity.