5 Clinical Trials for Various Conditions
The current protocol is composed of two studies. The first study is designed to carefully evaluate the safety of high-dose salmeterol/fluticasone (Advair HFA) versus placebo (hydrofluoroalkane, HFA) administration over 7 days, as well as the efficacy of the study drug to increase exercise performance, in healthy individuals exercising under hypoxic, simulated high-altitude conditions (Phase 1/2a study). The second study will examine sensitive measures of cardiopulmonary function using invasive cardiopulmonary testing, in both HAPE-sensitive and HAPE-resistant individuals, to assess the potential efficacy of salmeterol/fluticasone to prevent pulmonary edema and to enhance exercise capacity (Phase 2a) in these individuals.
The primary objective is to evaluate the efficacy of continuous positive pressure on resolution of high-altitude pulmonary edema vs high flow oxygen. The secondary objective is to derive an incidence of high-altitude pulmonary edema based on the elevation and timing from which the subject arrives. Additionally, in a convenience sample of the base study population, an ultrasound evaluation for the presence of B lines in the lungs will be conducted after 2 hours.
The overall goal of this study is to detect preclinical signs of HAPE by lung ultrasonography and evaluate the effectiveness of acetazolamide at decreasing pulmonary edema by using ultrasound.
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.
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.