18 Clinical Trials for Various Conditions
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.
This study is designed to be the first to examine the novel drug budesonide for prevention of acute mountain sickness in comparison to acetazolamide and in the context of rapid ascent to high altitude. The investigators will accomplish these objectives with a prospective, double blinded view of a large population of hikers who are ascending at their own rate in a true hiking environment.
The proposed study is a prospective, randomized, double-blind, placebo-controlled clinical trial evaluating ibuprofen and placebo for the prevention of neurological forms of altitude illness \[including high altitude headache (HAH), acute mountain sickness (AMS), high altitude cerebral edema (HACE), and an emerging concept of High Altitude Anxiety\]. The study will take place in the spring and summer of 2012 at the Marine Corps Mountain Warfare Training Center in the Eastern Sierras near Bridgeport, California. US Marines from near sea level will participate in battalion-level training exercises at between 8,500-11,500 Feet, where some altitude illness is expected. Concurrent measures used to determine objective markers of altitude illness, such that validated clinical scales, rapid cognitive screening tests, will inform us of symptoms of altitude illness.
This is a research study on Altitude Illness. From the information collected and studied in this project we hope to learn more about Altitude Illness, including factors that may affect and prevent the development and progression of this condition. We hope to learn if the commonly used non-steroidal anti-inflammatory medication, ibuprofen can prevent altitude illness. Possible participants in this study are healthy adults who indicated they would like to participate, learn about altitude illness, and desire to hike Barcroft Peak. Stanford University researchers hope to enroll about 100 participants.
During ascent to high altitude there is a physiologic response to hypoxia that results in an elevated pulmonary arterial pressure associated with decreased exercise performance, altitude-induced pulmonary hypertension, and high altitude pulmonary edema (HAPE). Riociguat is a novel agent from Bayer Pharmaceuticals that has already demonstrated effectiveness in the treatment of pulmonary hypertension, and it may prove to be beneficial in cases of altitude-induced pulmonary hypertension or HAPE. This research study, composed of 20 healthy volunteers ages 18-40 years, will attempt to mimic the decreased oxygen supply and elevated pulmonary artery pressures found in conditions of high altitude, allowing observation of the effects of riociguat and exercise on pulmonary arterial pressure, arterial oxygenation, and exercise performance. Prior to entering the hypobaric chamber, subjects will have radial arterial lines and pulmonary artery catheters placed to obtain arterial and pulmonary artery pressure measurements. Subjects will then enter the hypobaric chamber and perform exercise tolerance tests at a simulated altitude of 15,000 feet on an electrically braked ergometer (exercise bike) before and after administration of riociguat. If, after administration of riociguat and exposure to a simulated altitude of 15,000 feet, the exercise performance is improved and observed pulmonary artery pressures are lower than those measurements seen prior to administration of riociguat, this could lead to development of a prophylactic and/or treatment strategy for HAPE and high-altitude pulmonary hypertension. Statistical analysis will compare the variables of pulmonary artery pressure, radial arterial pressure, ventilation rate, cardiac output, PaO2, and work rate at exhaustion before and after administration of the drug riociguat. The investigator's hypothesis is that riociguat will decrease pulmonary artery pressure and improve gas exchange and exercise performance at altitude.
This safety study is the first in a series of studies testing the application of the combination of aminophylline and methazolamide.
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
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
Investigating the utility of prophylactic treatment with iron sucrose and/or erythropoietin on the prevention of acute mountain sickness in fit, young, healthy individuals.
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.
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 aims of this proposal are to test current USN procedures for adjusting decompression procedures during air diving at 8,000 and 10,000 ft altitude and to provide a decompression algorithm for no-stop dives to 100 feet of sea water (fsw) at 10,000 and 12,000 ft altitude using enriched O2 (PO2=1.3 ATM). Additionally, the experiments will determine whether a period of hyperbaric hyperoxia, such as would be experienced during a dive at altitude, reverses altitude acclimatization, resulting in a return of acute mountain sickness (AMS) symptoms.
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.
Ibuprofen is often taken by travelers to high altitude to treat the symptoms of acute mountain sickness such as headache and malaise. However, the blunting of inflammation by ibuprofen may slow the process of acclimatization to altitude, which relies on mediators of inflammation for adjustments in breathing. The study randomizes healthy subjects to receive ibuprofen or placebo and then ascend to altitude (12,500 feet). Blood cytokines and non-invasive measurements of blood and tissue oxygen levels will be made for 48 hours at altitude. The hypothesis being tested is that subjects receiving ibuprofen will have lower blood and tissue oxygen levels after 48 hours at altitude than will placebo subjects.
This is a phase 4, randomized, double-blinded interventional trial comparing alternative doses of Acetazolamide for the prevention of High Altitude Illness.
This study is being conducted to determine the effectiveness of using two FDA approved medications in concert to reduce the likelihood of sickness due to low oxygen levels and to reduce the decrement in physical performance at higher elevations. The investigators hypothesize that this drug combination will reduce the symptoms of acute mountain sickness and improve exercise performance at high altitude compared to placebo.
Acute exposure of the unacclimatized human body to high altitude leads to health complications, such as loss of exercise performance capacity and fatigue. The investigators have found that the combination of the xanthine drug theophylline and the endothelin receptor antagonist ambrisentan improves the exercise performance capacity of rats under simulated high altitude. In young, healthy human volunteers, this combination of drugs has not increase toxicity over the single compounds under sea-level conditions. The aim of this study is to test whether the combination of theophylline, supplied as its more soluble formulation aminophylline, and ambrisentan, are also safe to take under simulated high altitude of 4,267 meters, under both resting and exercising conditions. The study also aims to test whether this drug combination improves exercise capacity in humans. In this study, human subjects will be randomized to one of four treatment sequences and receive the same study drug(s) throughout all procedures. The study consists of an initial exercise test, followed by two cycles of drug testing at simulated high altitude: Cycle 1 - resting subjects receiving study drug at simulated altitude and continually monitored for safety with pharmacodynamic and pharmacokinetic assessments; and Cycle 2, the same as Cycle 1, with the addition of exercise testing. It is hypothesized that the combination of aminophylline and ambrisentan is not only safe under simulated high altitude, but also improves exercise performance capacity, in comparison with placebo.
This study will validate the experimental method and chamber facility at the Duke Center for Hyperbaric Medicine \& Environmental Physiology and test team capabilities to support NASA decompression sickness (DCS) studies. This project is related to development of protocols for extravehicular activity (EVA, "spacewalks") to minimize the risk of decompression sickness. Duke will perform four test days, collecting and recording data each day. Each test day will involve 3 volunteer subjects ages 18-50 years, who will breathe 100% oxygen for 6 hours. This will be followed by 6 hours in the hypobaric chamber at 1/3 atmosphere, during which subjects will perform various tasks, including arm and leg exercises, and undergo ultrasound testing to detect vascular bubbles. End-points will include bubble scores, and decompression sickness (DCS). If subjects develop DCS symptoms they will immediately be recompressed to ambient pressure and be assessed and treated.