Active clinical trials for "Altitude Sickness"

The purpose of this proposal is to compare the physiological effects of acetazolamide (AZ) and methazolamide (MZ) on the control of breathing and hypoxic pulmonary vasoconstriction. The first objective is to assess the effects of AZ and MZ on the control of breathing in normoxia and hypoxia. To achieve this the ventilatory interaction between oxygen and carbon dioxide will be measured and effects compared between placebo, AZ, and MZ conditions. In addition, the isocapnic and poikilocapnic hypoxic ventilatory response and hypercapnic ventilatory response will be measured with each drug. The second objective is to assess the effects of AZ and MZ on the control of the pulmonary vasculature during hypoxia. Pulmonary pressure and cardiac output will be measured during 60 minutes of poikilocapnic hypoxia.

This study aims to assess the effect of two drugs for the treatment of chronic mountain sickness in highlanders.

A randomized, double-blinded study administering budesonide, a medication to reduce inflammation in the lungs, to healthy volunteers to examine effects on altitude illness prevention by spending 18 hours overnight at 14,000 ft elevation.

High altitude pulmonary edema (HAPE) is mostly treated with supplemental oxygen, nifedipine 30mg twice a day, rest, limiting cold exposure and descent (simulated or actual) Gamow Bag provides simulated descent and buy time for actual descent. CPAP is claimed to be effective in many case reports to treat HAPE temporarily until actual descent is taken place. This study aims to evaluate the role of CPAP in treating HAPE at those high altitude stations where Gamow bag is not available and immediate descent is not possible.

Diseases associated with chronic hypoxemia like chronic obstructive pulmonary disease (COPD) or emphysema, represent major medical and socio-economical problems and one of the leading cause of morbidity and mortality in the western countries. Recently, is has been shown that cardiovascular (CV) diseases contribute highly to the morbidity and mortality of these patients. Furthermore, increasing evidence suggest that systemic vascular dysfunction play a central role in the mediation of the increased CV risk in patients with COPD. However the underlying mechanisms of vascular dysfunction in these patients are incompletely understood. Chronic mountain sickness (CMS) is characterized by chronic hypoxemia related at least in part to hypoventilation; it affects relatively young adults, and may therefore allow to study the effects of chronic hypoxemia. The investigators therefore will assess systemic vascular function and test the hypothesis that increased oxidative stress is responsible for this dysfunction. Since polyglobulia is a hallmark of chronic hypoxemia and has been suggested to affect vascular function, the investigators will test the effects of hemodilution on vascular function. Then, the investigators will test the effects of acute oxygen application and 1 month antioxidative dietary supplement on vascular function. Preliminary data suggest that offspring of CMS patients may display pulmonary and systemic vascular dysfunction. Antioxidant administration is know to improve vascular function. We will test the acute effect of Vitamin C in this setting. Finally, since there is considerable inter-individual variability of pulmonary artery pressure among CMS patients and the presence of a patent foramen ovale (PFO)is increased in clinical conditions associated with pulmonary hypertension and hypoxemia, we will assess the prevalence of PFO in healthy high altitude dwellers and in CMS patients and its effects on pulmonary artery pressure at rest and during mild exercise.

To evaluate the additive value of tadalafil given together with Diamox (acetazolamide) in preventing acute mountain sickness in travelers to high altitude areas.

The trial evaluates the role of ascent protocol on acute mountain sickness and cardio-respiratory physiology during an ascent to Muztagh Ata (7546m). Two groups of mountaineers ascend with different acclimatization time to the summit. The prevalence and severity of symptoms of acute mountain sickness are evaluated along with physiologic variables.

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.

This study analyses both Protein Expression and emotional alterations during hypobaric hypoxia in volunteers of different groups.

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.