Active clinical trials for "Hypoxia"

1) Oxygen Transport in Normobaric versus Hypobaric Hypoxia. 2) The purpose of this study is to examine acute responses in arterial and muscle tissue oxygenation during incremental exercise in normobaric versus hypobaric hypoxia. 3) The participants in this study will consist of 12 recreationally active males and females between the ages of 19 and 45.Recreationally active is defined as participating in moderate to vigorous physical activity for 30 minutes at least 3 days per week.4) Subjects will complete an incremental cycle test to volitional fatigue in three conditions in a randomized counter-balanced order, normobaric normoxia (20.9% O2, 730 mmHg), normobaric hypoxia (14.3% O2, 730 mmHg) and hypobaric hypoxia (20.9% O2, 530mmHg). Two of the three trials will be conducted in an environmental chamber to simulate normobaric normoxia at 350 m (elevation of Omaha, NE) and normobaric hypoxia at 3094 m (elevation of Leadville, CO). The hypobaric hypoxia trial will be conducted in Leadville, Colorado at 3094 m. Trials will be separated by at least two days. Rating of perceived exertion, heart rate, blood oxygenation, respiration rate, muscle tissue oxygenation, and whole body gases will be analyzed during the trials. 5) There is no follow-up as a part of this study.

The pilot study aims to evaluate a prototype system that enables military pilots to train under conditions of orthostatic hypotension and ischemic hypoxia. Both of these phenomena are experienced by aircraft crews of mainly highly maneuverable aircraft, and their syndromes include loss of color vision, loss of peripheral vision, blackout and finally G-induced loss of consciousness (G-LOC). A motorized tilt table to generate orthostatic (ORTHO) stress combined with an automatically controlled lower body negative pressure (LBNP) chamber to extort pooling of blood in the lower extremities has been developed in order to obtain new knowledge on counteracting the above-mentioned effects and minimizing the risk of their occurrence. This will help optimize the selection procedures of candidates with the best physiological predispositions to work as military pilots. The system is equipped with modules for monitoring biomedical parameters of a subject, including cerebral oxygenation, which ensures their safety and provides a source of data for performing advanced analyses. The ORTHO-LBNP system has been subjected to comprehensive laboratory tests and after a successful testing is ready for a pilot study involving pilots and/or cadets of the Polish Air Force Academy (PAFA). It is anticipated that new indicators will be proposed to enable an objective assessment of the predispositions to pursue a military pilot career. The prototype system can be easily adaptable to the needs of clinical and sports medicine as well as rehabilitation.

Aim of this study was to evaluate the hypoxic response during hypobaric flight simulation in normal individuals as well as in normocapnic and hypercapnic COPD patients as well as to evaluate the impact of a flight simulation on walking endurance in these patients.

A ketogenic diet (KD) reduces daily carbohydrates (CHOs) ingestion by replacing most calories with fat. KD is of increasing interest among athletes because it may increase their maximal oxygen uptake (VO2max), the principal performance limitation at high altitudes. The investigators examined the tolerance of a 4-week isocaloric KD (ICKD) under simulated hypoxia and the possibility of evaluating ICKD performance benefits with a maximal graded exercise bike test under hypoxia and collected data on the effect of the diet on performance markers and arterial blood gases.

The purpose of this clinical study is to validate the oxygen saturation (SpO2) accuracy of the RDS MultiSense® Pulse Oximetry during non-motion conditions over the range of 70-100% arterial oxygen saturation (SaO2) as compared to arterial blood samples assessed by measuring carbon monoxide (CO) bound to hemoglobin by CO-Oximetry. Additionally, data will be collected for heart rate accuracy as compared to reference ECG. The end goal is to provide supporting documentation for the SpO2 and heart rate accuracy validation for RDS MultiSense® Pulse Oximetry. A minimum of 10 healthy adult male and female participants, ranging in age and pigmentation from light to dark, will be enrolled in the study to meet the study design requirements defined by International Organization for Standardization ISO 80601-2-61:2017: corrected version 2018-02 and by the FDA's Guidance for Pulse Oximeters (March 4, 2013). The participants will have an arterial catheter placed in the radial artery to allow for simultaneous blood samples during stable plateaus of induced hypoxic levels. The investigational device will be placed on the placed on the thorax of the participants (patch on the upper back and external electrode on the right pectoral) per the instructions for use. Simultaneous data collection will be set up for the system under test and control oximeter.

The number of people with type 2 diabetes mellitus (T2DM) continuing to rise, this pandemic is expected to reach 700 million people by 2045. T2DM is a metabolic condition characterized by progressive insulin resistance and chronic hyperglycemia (high blood glucose concentrations). Hyperglycaemia increases the risk of both micro- and macrovascular damage, whilst interventions that reduce blood glucose mitigate this risk. Weight loss, achieved through exercise and dietary modification, is effective at reducing hyperglycaemia. However, despite the clear benefits of exercise and weight loss, diverse psychological, sociological and logistical factors can make it difficult for some individuals with T2DM to initiate, or adhere to, these lifestyle interventions. Alternative approaches to treatment are therefore required. The purpose of this research project is to investigate whether 10-days of overnight exposure to moderate hypoxia is effective at improving blood glucose control in individuals with T2DM and to provide insight into the physiological mechanisms responsible for any beneficial effects.

Ascent to altitude lowers oxygen saturation. In addition, sleep lowers oxygen saturation at any altitude. In a prior study, we observed that sleep at 8000 feet resulted in pronounced reduction in oxygen saturation, but did not result in reduced post sleep neurobehavioral performance or impaired sleep quality or quantity. We plan to do a more sophisticated physiological evaluation of the respiratory mechanisms responsible for the reduced oxygen saturation and determine if there are any adverse consequences to this level of intermittent hypoxia. We anticipate that central respiratory apnea is the physiologic mechanism, and that there will not be persistent changes in autonomic nervous activity measured by heart rate variability.

The prevalence of obstructive sleep apnea is high in the Veteran population. If not treated promptly, sleep apnea may result in daytime fatigue which may lead to increased prevalence of accidents while driving or in the workplace. Recent large scale epidemiological studies have shown that the prevalence of excessive daytime sleepiness increases in individuals who suffer from obstructive sleep apnea. Obstructive sleep apnea may also result in the development of hypertension and other cardiovascular disorders. Previous findings have shown that subjects with sleep apnea have a greater risk for developing coronary vascular disease compared to individuals that do not suffer from sleep apnea Thus, a significant amount of evidence suggests that sleep apnea is a major health concern in the Veteran population. Consequently, determining the mechanisms that may impact on the severity of sleep apnea and increase the prevalence of cardiovascular incidents associated with this disorder is important, as is discovering novel treatments.

In an avalanche burial with an air pocket hypercapnia (and hypoxia) develops within few minutes, hypercapnia increases the rate of cooling and therefore the development of hypothermia. The Triple H Syndrome (Hypoxia, Hypercapnia, Hypothermia) occurs. This specific combination of the three parameters is unique for avalanche burial with an air pocket. Every single parameter has a substantial effect on the hemoglobin-oxygen dissociation curve, but until now no study described the combination of these three parameters. This curve will be measured under these specific conditions in a specifically developed in vitro model, to quantify its shifts and to show if there are combined effects of pCO2 and temperature. The newly developed method will be validated in comparison with an established method. The project will be performed with whole blood, drawn by healthy volunteers, in an experimental setting. The samples will be blinded to the investigator and analyzed in a randomized manner.

Bone losses are well known to occur in response to unloading (in microgravity or during immobilisation) and in patients with chronic obstructive airway disease (COPD). However, it is unknown whether there is an interactive effect between hypoxia and musculoskeletal unloading upon bone and mineral metabolism. Fourteen non-obese men, who are otherwise healthy, will undergo 3x 21-day interventions; normobaric normoxic bed rest (NBR; FiO2=21%), normobaric hypoxic ambulatory confinement (HAMB; FiO2=14%; ~4000 m simulated altitude), and normobaric hypoxic bed rest (HBR; FiO2=14%). The effects of hypoxia and bedrest on bone metabolism and phosphor-calcic homeostasis will be assessed (before and during each intervention, and 14 days after each intervention period) using venous blood sampling, 24hr urine collections, and peripheral quantitative computerized tomography (pQCT).