View clinical trials related to Hypoxia.
Filter by:Mild intermittent hypoxia (IH) initiates sustained increases in chest wall and upper airway muscle activity in humans. This sustained increase is a form of respiratory plasticity known as long-term facilitation (LTF). Repeated daily exposure to mild IH that leads to the initiation of LTF of upper airway muscle activity could lead to increased stability of the upper airway. In line with PI's laboratory's mandate to develop innovative therapies to treat sleep apnea, this increased stability could ultimately reduce the continuous positive airway pressure (CPAP) required to treat obstructive sleep apnea (OSA) and improve compliance with this gold standard treatment. Improved compliance could ultimately serve to mitigate those comorbidities linked to sleep apnea. Moreover, in addition to improving CPAP compliance numerous studies indicate that mild IH has many direct beneficial effects on cardiovascular, neurocognitive and metabolic function. Thus, mild IH could serve as a multipronged therapeutic approach to treat sleep apnea. In accordance with this postulation, our proposal will determine if repeated daily exposure to mild IH serves as an adjunct therapy coupled with CPAP to mitigate associated co-morbidities via its direct effects on a variety of cardiovascular, metabolic and neurocognitive measures and indirectly by improving CPAP compliance. Modifications in autonomic (i.e. sympathetic nervous system activity) and cardiovascular (i.e. blood pressure) function will be the primary outcome measures coupled to secondary measures of metabolic and neurocognitive outcomes.
The purpose of this study is to validate the oxygen saturation (SpO2) accuracy of the Polso Monitoring System during non-motion conditions over the range of 70-100% SaO2 as compared to arterial blood samples assessed by CO-Oximetry for SpO2 validation
Subjects with known or suspected primary soft tissue sarcoma of the extremities may be eligible for this study. Subjects may participate in this study if they are at least 18 years of age. Most participants will be receiving care at the clinical practices of the University of Pennsylvania Health System. Positron emission tomography (PET/CT) imaging will be used to evaluate soft tissue sarcoma hypoxia using an investigational radiotracer, 18F-FMISO Subjects will also undergo an 18F-FDG PET/CT scan close to the time of their initial hypoxia PET/CT to compare in vivo measures of hypoxia to 18F-FDG uptake. The FDG PET/CT may be performed as part of standard clinical care or as a research scan. Both PET/CT scans will occur prior to starting new therapy.
Patients with chronic lung diseases travelling by plane often suffer with symptoms related to lower oxygen levels they are exposed to while flying. Therefore, patients with respiratory conditions are routinely assessed to establish if they need supplemental oxygen in flight. A hypoxic altitude simulation test (HAST) is often part of this assessment and consists in having patients breathe a oxygen/nitrogen blend with a lower oxygen concentration compared to normal room air, simulating in-flight conditions. Oxygen levels are measured before and after the test through a blood sample (from the earlobe or an artery in the wrist) and with a finger probe. In-flight oxygen is required if the oxygen level in the blood is lower than 6.6 kPa. HASTs are time consuming, costly, and require a dedicated hospital appointment. Using historical data, the Investigators developed scores based on capillary blood gas (blood sample from the earlobe), diagnosis and sex to predict the outcome of the HASTs. The Investigators validated the proposed scores in a separate historic cohort of patients and showed it had good concordance with the HASTs results. In this study, the Investigators want to confirm prospectively if the score, based on blood results (venous and/or earlobe), can predict the outcome of the HASTs and therefore reduce the number of tests performed, travel time for patients, and costs for the NHS. All patients, aged 18 or older, who are having a HAST for clinical purposes at the cardio-respiratory lab at Leeds Teaching Hospital NHS Trust will be invited to take part in the study. The Investigators will record diagnosis, results of HAST and previous spirometry from the medical notes, perform a spirometry if not done in the previous 12 months and collect a blood sample (one tube, 4 mls). With these data, the Investigators will calculate the score and assess its agreement with the outcome of the HAST. Each participant's involvement in the study will last for approximately 90-120 minutes, which is the normal duration of a HAST. The Investigators aim to include up to 280 subjects in the study.
The imaging of cerebral oxygenation is an extremely important tool in understanding the pathophysiology of the tumor and for adaptation of therapies according to hypoxia. Currently, imaging of cerebral oxygenation is mainly performed by the use of Positron Emission Tomography (PET). Thus, the investigators have been able to show that the FMISO radiotracer can reveal tumor hypoxia (HypOnco study, promotor: Caen University Hospital, main investigator: J.S. Guillamo). After injection of the radiotracer, increased uptake is observed in the regions for which the tissue oxygen pressure is less than 10 mmHg (the healthy brain with a tissue oxygen pressure (ptO2) ≈ 40mmHg). Although PET is a reference methodology, it is not widely practiced mainly because of radioactive sources. Magnetic Resonance Imaging (MRI) would bypass the previously mentioned PET limitations. The investigators have recently shown that a measure of local oxygen saturation could be obtained by MRI. This methodology has also been implemented at a clinical scale on lower field MRI magnets, but its formal validation in a clinical situation remains to be demonstrated with respect to FMISO. The major advantage of this methodology is that MRI is already performed in routine practice for patients. Measuring tissue oxygenation with MRI (SatO2-MRI) would not add additional examination for the patient. In addition, MRI is a non-ionizing methodology with a very good spatial resolution compared to PET, this should help to better understand intratumoral heterogeneity. Similarly, in preclinical studies, the investigators have shown in a context of mild hypoxia that SatO2-MRI may be more sensitive than PET. The investigators propose a study to compare in patients with glial tumors, images obtained by 3 Tesla MRI of SatO2-MRI to the hypoxia maps obtained by FMISO PET. These imaging studies will be confronted with studies carried out in immunohistochemistry on biopsies / resection allowing to reveal and to quantify by image analysis the expression of the factors induced by hypoxia (HIF1, HIF2). This study should include 20 patients with glioma (15 high-grade patients and 5 low-grade patients) in pre-surgery. The aim is to show that SatO2-MRI is a relevant methodology (in terms of sensitivity, specificity) for assessing intratumoral oxygenation in a context of brain tumors. This fits perfectly into an era of personalized medicine where functional imaging finds its meaning.
This study to assess the oxygen saturation accuracy of the Beddr SleepTuner in profound hypoxia.
The degree to which endurance exercise performance is diminished in acute hypoxia is variable and appears to be the result of several different physiological processes, however this research focuses on hypoxic pulmonary vasoconstriction (HPV). Sildenafil, a pulmonary vasodilator, has been used with mixed results to improve athletic performance in hypoxia. Because sildenafil has been shown to reduce HPV in some individuals, we believe that its effectiveness is closely related to the magnitude of the HPV response and the degree that individual exercise performance declines in hypoxia. This research will investigate the relationship between sildenafil, HPV, and exercise performance.
This study involved human volunteers undertaking a high-altitude expedition. It assessed changes in physiological parameters of relevance to high-altitude cardiopulmonary physiology. Participants included a subgroup of those taking part in an existing adventurous training expedition and were randomised in a 1:1 fashion to receive either intravenous iron or normal saline several weeks prior to departure. During the expedition, participants were investigated by means of transthoracic echocardiography, peripheral oxygen saturation measurement and heart rate monitoring and through the drawing of venous blood samples. Bloods were later analysed for markers of iron status.
The purpose of the study is to determine whether tele-expertise would be more effective and more cost-effective for the Interpretation of MRI Among Neonates with high risk of neurological sequelae
Obstructive sleep apnea (OSA) is a common condition associated with significant adverse health outcomes. Our overarching hypothesis is that patients with OSA and hypoxia (H-OSA) have greater degrees of insulin resistance in both liver and adipose tissue when compared to those without hypoxia (NH-OSA) thus leading to increased risk for the development of diabetes in the former group.