View clinical trials related to Altitude Sickness.
Filter by:This study is a trial looking at a drug to help prevent acute mountain sickness. The drug is prochlorperazine, a drug commonly used to treat nausea vomiting and headache. Participants will either take the drug or a placebo, and hike to and sleep at the summit of Mount Blue Sky located at 4,348 meters (14,265 feet).
Rescue services in mountainous regions are frequently called to missions at altitudes >3000 m. Under the difficult conditions of acute exposure to altitude, the crews then have to undertake demanding medical and rescue measures. Previous studies in non-medical personnel, such as astronauts, aircraft pilots, and military helicopter pilots have found that the lack of oxygen associated with acute exposure to altitude may impair cognitive functions. No data exists on the effect this may have on the performance of medical staff in terms of patient examination, communication, decision-making, planning, and overall patient care. This study aims to close this knowledge gap. The investigators of this study aim to make rescue missions to high altitude safer for both the patients and the rescuers. To assess the effect of high altitude on patient care, the investigators recruit highly trained medical specialists who will perform patient care in simulated scenarios both at high altitude and at low altitude. These scenarios will be recorded and the performance of the medical specialists judged by independent reviewers. The medical specialists will also perform in simulated scenarios at high altitude two more times: once with supplementary oxygen, and once after spending a night at high altitude. the investigators do this to evaluate whether supplementary oxygen improves their performance, and whether symptoms of acute mountain sickness (which usually develop after spending the first night at high altitude) decreases their performance further.
It was reported that up to 76% people who rapidly ascend to the altitude higher than 4500 m without sufficient acclimatization will have AMS which often develops 6-8 hours after reaching at high altitude. AMS could be improved if there is no continuous ascent although central sleep apnea may persist much longer. It has also been well documented that exercise capacity was impaired at high altitude. Oxygen inhalation is the most effective treatment method, but it is impractical for outdoor activities because of the large volume required. There are some drugs such as acetazolamide, and ibuprofen for relieving AMS but side effects and inconsistent treatment effect made them to be difficulty for routine use. It is noted that adding CO2 might be useful for improvement of hypoxia and exercise ability and eliminating CSA. There is no available device which can accurately supply constant CO2 and is functionally free of dead space. We innovated a portable device with a special mask for supplement of CO2 for prophylaxis and treatment of AMS.
To understand alterations in glycogen and molecular regulation of skeletal muscle glucose uptake, glycogen synthesis, and muscle protein recovery when consuming CHO (glucose) or CHO+PRO (glucose + whey) post-exercise during unacclimatized high altitude exposure, randomized crossover double blinded studies will be conducted in the hypobaric/hypoxic chamber at USARIEM Table 1. Briefly, the study consists of a 2 day baseline period at SL followed by two, 3 day trial periods (with the 3rd day being a testing day) at HA. The baseline is separated from trial 1 for a least a day, and trial 1 & 2 separated by at least 4 days. Volunteers will consume CHO (glucose) or CHO+PRO (glucose + whey) drinks post-exercise during unacclimatized high altitude exposure during the two trial periods. The order of the drinks will be randomized (using a random number generator such as randomizer.org) and kept by a study staff not directly involved in data collection to maintain blinding.
A field-based trial was conducted to determine if oral prochlorperazine demonstrates efficacy in the prophylactic treatment of AMS, and/or decreases the incidence of the symptoms of acute mountain sickness including headache, GI symptoms, fatigue and dizziness based on data collected in the Lake Louise AMS score.
- Cognitive assessment of the influence of a 4-week proprietary training program under normobaric hypoxia conditions on the levels of inflammatory markers, disturbances in prooxidant-antioxidant balance, degree of intestinal damage, and mitochondrial energy production rate in young sedentary males. - Applied objective: Development of practical training guidelines utilizing training in normobaric hypoxia conditions to enhance mechanisms related to oxygen transport, adaptive changes within the immune system, body's antioxidant capacity, gut permeability, substrate utilization efficiency, and mitochondrial function for coaches and athletes.
One approach to significantly reducing resistance training intensity while maintaining effectiveness in muscle mass and strength development involves conducting training sessions under hypoxic conditions. This is likely due to heightened physiological responses. While sports science research indicates a substantial impact of hypoxic conditions on immediate increases in metabolic stress and augmented hormonal responses, recent findings suggest that the role of their influence on skeletal muscle adaptations post-resistance training under hypoxic conditions remains unknown. Additionally, there is a lack of reports on whether the type of hypoxia applied via blood flow restriction or chamber differentiates the increase in secretion of these catecholamines in both immediate and long-term aspects.
Apparent hypoxia-induced insulin insensitivity along with alterations in glucose kinetics suggests reduction in glucose uptake by the peripheral tissue is a primary factor contributing to reductions in exogenous glucose oxidation at HA. As such, the primary objective of this study is to determine the ability of an insulin sensitizer (Pioglitazone, PIO) to enhance exogenous glucose oxidation and metabolic clearance rate during metabolically-matched, steady-state exercise during acute HA exposure compared to placebo (PLA) in native lowlanders. Secondary objective of this study will be to assess the impact of PIO on markers of inflammation and iron status compared to PLA. This randomized crossover placebo control double blinded study will examine substrate oxidation and glucose kinetic responses to ingesting supplemental carbohydrate (glucose) during metabolically-matched, steady-state exercise with acute (~5 h) exposure to HA (460 mmHg, or 4300m, barometric pressure similar to Pike's Peak) after receiving PIO (HA+PIO), or after receiving a matched placebo (HA+PLA). Eight healthy, recreationally active males between the ages of 18-39 yrs will be required to complete this study. Following a 4 day glycogen normalization period receiving PIO or PLA daily, volunteers will complete two 80-min trials, performing metabolically-matched, steady-state aerobic (same absolute workload corresponding to ~55 ± 5% of V̇O2peak at HA) exercise on a treadmill, and consuming 145 g of glucose (1.8 g/min); one trial with HA+PIO and the other with HA+PLA. A dual glucose tracer (13C-glucose oral ingestion and [6,6-2H2]-glucose primed, continuous infusion) technique and indirect calorimetry will be used to selectively analyze endogenous and exogenous glucose oxidation, as well as glucose rate of appearance (Ra), disappearance (Rd) and metabolic clearance rate (MCR). Serial blood samples will be collected during each trial to assess endocrine and circulating substrate responses to exercise, carbohydrate, and hypoxia with or without PIO. All trials will occur at the same time of day in the USARIEM hypobaric/hypoxic chamber and be separated by a minimum 10-d washout period. The primary risks associated with this study include those associated with acute hypobaric hypoxia, exercise, and blood sampling.
The main objective of the study is to evaluate the physiological-biochemical effects of physical training under artificially altered climatic conditions (using a hypoxic thermoclimatic chamber) in particular to determine the effect of such training on exercise capacity and physiological response, including the effect of training in high-performance athletes. The study will evaluate the effects of physical training and the simultaneous application of hypoxia and heat/cold on aerobic and anaerobic capacity and the physiological response of the human body. The aim of the study is to find the most favourable environmental conditions for physical training in order to maximise physical performance.
Over the last 20 years, extracorporeal membrane oxygenation (ECMO) has been used to support adult patients with respiratory or cardiac failure who are unlikely to survive conventional treatment methods. ECMO circuit, pump, and oxygenator technology improvements permit safer perfusion for extended periods. The prolonged use of an ECMO circuit increases the risk of membrane lung (ML) dysfunction. The ML is responsible for taking in oxygen and removing carbon dioxide. The non-biologic surface of the ML triggers inflammatory and coagulation pathways, resulting in the formation of blood clots, breakdown of fibrin, and activation of white blood cells, which ultimately leads to ML dysfunction. Coagulation and fibrinolysis activation can cause systemic coagulopathy or hemolysis, and the deposition of blood clots can block blood flow. Moreover, the accumulation of moisture in the gas phase and the buildup of protein and cellular debris in the blood phase may contribute to shunt and dead-space physiology, respectively, impairing the exchange of gases. These three categories-hematologic abnormalities, mechanical obstruction, and inadequate gas exchange-account for most ML exchanges. Worsening oxygenation during ECMO should prompt quantification of oxygen transfer. ML exchange is indicated when the ML can no longer meet the patient's oxygen demand. The partial pressure of Post-ML arterial oxygen less than 200 mmHg is the most important consideration in this decision. In some high-altitude regions of China, ECMO treatment is also routinely conducted. The experiences above are derived from low-altitude areas, and whether they apply in high-altitude regions is still being determined. This study aimed to explore the significantly lower membrane lung oxygen uptake in high-altitude regions compared to low-altitude areas.