Active clinical trials for "Altitude Sickness"

AMS (acute mountain sickness) affects those who ascend too high (>2000m) too fast. Acetazolamide is an effective drug for the prevention of AMS where proper acclimatization with gradual ascent may not be an option. AMS presents with headache and other non-specific symptoms such as nausea, tiredness, and dizziness. Because of the side effects of acetazolamide such as a tingling sensation, other drugs have been investigated to see if they will prevent AMS. Ibuprofen has recently been shown to prevent AMS. In this present study the investigators want to see if acetaminophen can also prevent AMS as acetaminophen unlike ibuprofen does not have gastric side effects. Second, because acetaminophen has much less anti-inflammatory component than ibuprofen, it may also provide some insight into the pathophysiology of AMS if acetaminophen were found to be effective in the prevention of AMS.

Individuals traveling to altitudes above 8,000 feet may suffer from impaired exercise and cognitive performance, and acute mountain sickness (AMS). Decreased barometric pressure, which leads to low blood oxygen levels, is the primary cause of these disorders. Symptoms of AMS are characterized by headache, nausea, vomiting, dizziness, fatigue, and difficulty sleeping. The goal of this research is to identify whether Respiratory Muscle Training will improve physical and cognitive performance, and reduce the symptoms of AMS, at simulated high altitude.

The study is examining if an over-the-counter device (Theravent) worn while sleeping can reduce acute mountain sickness upon awakening in a high altitude trekking population.

This double blind randomized trial will compare acetazolamide taken the morning of ascent to acetazolamide taken the evening prior to ascent for the prevention of acute mountain sickness (AMS). The day of ascent dosing has not been studied as a powered primary outcome. 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

Randomized, placebo controlled trial evaluating the effect of acetazolamide on sleep disordered breathing in lowlanders older than 40 years travelling from 760 m to 3'100 m.

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.

Prospective interventional trial in lowlanders evaluating the effect of acute exposure, acclimatization and re-exposure to high altitude on global cognitive function.

A double-blind placebo controlled study To compare the effect of tadalafil and dexamethasone versus placebo on Ppa and pulmonary edema formation in subjects susceptible to HAPE. To investigate the effect of dexamethasone on alveolar fluid clearance, as assessed by measurement of the nasal potential difference, and prevention of HAPE. To investigate the effect of the tadalafil and dexamethasone versus placebo on the dynamic CBF autoregulation properties and on the development of AMS in HAPE susceptible subjects.

Acute mountain sickness (AMS), high altitude pulmonary edema (HAPE), and high altitude cerebral edema (HACE) are complications of rapid ascent to high altitude. Several features suggest that raised intracranial pressure (ICP) may be an important factor in the pathogenesis of AMS. Magnetic resonance imaging of HACE patients has demonstrated that the oedema in HACE is of the vasogenic, rather that cytotoxic, type. Thus it is likely that cerebrovascular permeability has an important role in the development of AMS and HACE. Reactive oxygen species (ROS) have been shown to alter the permeability of the blood-brain barrier in severe ischaemia, causing vasogenic cerebral oedema. Endogenous antioxidant systems may have some capacity to respond to oxidative stress in hypoxia. The plasma concentration of urate, a powerful endogenous antioxidant, rises on acute exposure to high altitude and may play a crucial antioxidant role in systemic hypoxia. This antioxidant prevents free-radical induced cerebral oedema in animal models. There are numerous sources of ROS in hypoxia, including the mitochondrial electron transfer chain, haemoglobin (Hb) autoxidation and xanthine oxidase activity. There have been several reports of raised markers of oxidative stress in humans at moderate altitude (<3000m). Oral antioxidant supplementation with preparations containing vitamins C and E in humans at altitude has been shown to decrease breath pentanes (a marker of oxidative stress), and improve erythrocyte filterability. In a small randomised controlled trial, Bailey and Davies demonstrated a significant reduction in symptoms of AMS in subjects taking an oral antioxidant cocktail. The antioxidants alpha-lipoic acid, vitamin C and vitamin E act synergistically to provide membrane protection from free radical damage, and may protect against hypoxia-induced vascular leakage. We hypothesised that this combination of antioxidants would reduce the severity of acute mountain sickness, and reduce pulmonary artery pressures, in healthy lowlanders acutely exposed to high altitude.

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.