Active clinical trials for "Altitude Sickness"

The main purpose of this study is to determine if a drug (acetyl-cysteine or ACCY) can increase the amount of oxygen in your body at a high altitude of 11,500 feet. ACCY is approved by the Food and Drug Administration (FDA) as a treatment or antidote for Tylenol overdoses. Other forms of ACCY are also sold over-the-counter as nutritional supplements. In this study, the FDA-approved form of ACCY will be used "off-label" (meaning in a way not approved by the FDA). This study is being conducted by researchers from the United States Army Research Institute of Environmental Medicine (USARIEM). The study will take place in the Altitude Chamber located in the basement of USARIEM. A total of approximately 30 volunteers (men and women, military and civilians) will take part in the study. They can expect to be in the study for a minimum of a few hours each day for two weeks. The investigators hypothesize that ACCY will improve ventilation and oxygenation while at altitude.

Acute Mountain Sickness (AMS) is a well-documented syndrome that affects 42% of non-acclimatized individuals traveling to altitudes above 10,000 feet. Decreased barometric pressure, which leads to low blood oxygen levels, is the primary casual factor of AMS. Symptoms of AMS are characterized by headache, nausea, vomiting, dizziness, fatigue and difficultly sleeping. Moreover, when people travel to high altitude, cognitive performance and endurance exercise capacity are impaired. Therefore, the goal of this research is to identify effective pharmacological agents that will help reduce the symptoms of AMS and improve physical and cognitive performance at high altitude. The investigators will study the efficacy of the dietary supplement, quercetin, the drugs nifedipine (extended release) and methazolamide taken together, the drug metformin, and the drug nitrite in reducing symptoms of AMS and improving cognitive and exercise performance at high altitudes.

This research will evaluate nutrition requirements for missions at high altitude (i.e. >7800 feet above sea level) and the information obtained can be used to optimize nutrient content specifications for combat rations. The objectives are: Determine whether loss of lean body mass resulting from negative calorie balance over a 22-d period at high altitude can be prevented by increasing dietary protein intake. Determine the efficacy of carbohydrate (glucose and fructose) supplementation on aerobic exercise performance at sea level, acute exposure to high altitude, and in response to 22-d period of negative calorie balance at high altitude. Determine cognitive function, sleep patterns, and behavioral responses to high altitude and underfeeding. Determine appetite and eating behavior in response to high altitude and sustained underfeeding. Examine the effects of high altitude, negative calorie balance, dietary intake manipulations on gut health.

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.

The aim of this randomized, crossover clinical trial is to determine the efficacy of a gut microbiota-targeted nutritional intervention containing a blend of fermentable fibers and polyphenols (FP) for mitigating increases in GI permeability, and decrements in immune function and neuropsychologic performance following rapid ascent to simulated high altitude. Fifteen healthy young adults will participate in each of three study phases that include a 14-day supplementation period in which participants will consume 1 of 2 supplement bars: placebo (PL, will be consumed during 2 phases) and FP supplementation (will be consumed during one phase only). During the final 2-d of each phase, participants will live in a hypobaric chamber under sea level or high altitude conditions.

Randomized, placebo controlled trial evaluating efficacy of acetazolamide in preventing acute mountain sickness in lowlanders older than 40 years travelling from 760 m to 3'100 m.

The specific aim of this study is to evaluate whether acetazolamide 125mg daily is no worse than acetazolamide 250mg daily in decreasing the incidence of acute mountain sickness (AMS) in travelers to high altitude. 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 cerebral autoregulation

Prospective interventional trial in lowlanders evaluating the effect of acute exposure, acclimatization and re-exposure to high altitude on psychomotor vigilance to measure sustained attention.

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.