View clinical trials related to Hypoxia.
Filter by:Many information is available regarding human adaptations to cold or hypoxia. Adaptations to these environments and physical exercise constitute responses to physiological stress aimed at amplifying the organism's reactions and improving its performance. However, studies conducted so far to understand these adaptations and their underlying mechanisms have been organized in a dissociated manner, with each study focusing on only one of these specific situations (cold, hypoxia, or exercise). Understanding cross-adaptations is crucial, as human beings are often simultaneously exposed to several of these stimuli, and understanding this cross-exposure can be considered a prerequisite for pre-acclimatization strategies to these different environments. Cross-adaptations has been defined as follows: "It simply involves considering that long-term exposure (either continuous or intermittent) to a given unfavorable environment not only increases tolerance to that particular environment but also leads to gains or losses of tolerance to other unfavorable factors that the adapted organism had never encountered before." When specifically examining cross-adaptations to cold and hypoxia, only one study focusing on the human model is available. The lack of perspectives and positions regarding the results calls for further investigations. The main objective of this study is to assess the effect of repeated exposures to cryostimulation on the variation of the respiratory exchange ratio in hypoxia during exercise.
This is a mixed-methods program evaluation from a health systems and policy perspective, involving (i) stakeholder analysis, (ii) policy-implementation gap analysis, and (iii) comparative country case studies. This study aims to understand how national oxygen strategies achieve impact at national, and subnational level, across country contexts, at what cost. The the investigators seek to: 1. Involve policymakers, implementers (including private sector), and medical oxygen users in identifying challenges and understanding potential solutions to medical oxygen access; 2. Generate new data on how medical oxygen systems work and can be improved from multiple perspectives; 3. Draw lessons on medical oxygen that can directly inform national and global practice and policy. This study will be conducted in 6 of the 9 countries participating in the Clinton Health Access Initiative (CHAI) led Medical Oxygen Implementation (MOXY) program (Uganda, Nigeria, Rwanda, Liberia, Lao PDR, Cambodia). Key informants will be selected representing government, non-governmental agencies, professional associations, private sector, and civil society. This study will be completed over 4 years, with timelines varying between country study sites.
Background: Sodium-glucose-cotransporter (SGLT) inhibition has been observed to reduce risk of cardiovascular events and kidney failure in persons with type 2 diabetes. People with type 1 diabetes also have increased risk of cardiovascular and kidney disease, and may benefit from SGLT-inhibition. The exact mechanism of how SGLT-inhibition benefits the kidneys are yet unknown. Change in renal hypoxia may be a factor. Objective: The primary aim of this study is to assess the effects of 12 weeks SGLT-1 and 2 inhibition on renal oxygenation in persons with type 1 diabetes and chronic kidney disease. Further aims are to study if renal oxygen consumption and response to SGLT-inhibition differs between people of African-Caribbean or Northern European decent. Additionally effects on left ventricular ejection fraction, kidney function and biomarkers in blood and urine will be explored. Method: 12 weeks treatment with oral sotagliflozin or matching placebo as intervention. Kidney oxygenation and perfusion parameters and left ventricular ejection fraction will be assessed by functional magnetic resonance imaging. Kidney function and biomarkers will be assessed according to local hospital laboratory guidelines. Design: Randomized, double-blinded, placebo-controlled, cross over intervention study. Study population: 69 persons with type 1 diabetes and diabetic kidney disease with albuminuria will be included, 39 at Steno Diabetes Center Copenhagen, 30 at King's College London. Endpoints: Primary end-point: Change from 0 to 12 weeks in dynamic R2*-weighted signal after treatment with sotagliflozin compared to placebo. Secondary endpoints: Change from 0 to 12 weeks with sotagliflozin compared with placebo on renal perfusion, renal artery flow, renal oxygen consumption, renal parenchymal triglyceride fraction, renal fibrosis, left ventricular ejection fraction, urinary albumin-creatinin ratio, ketone bodies, erythropoietin, pro brain natriuretic peptide, and plasma- and urine inflammation- and fibrosis biomarkers as well as difference after 12 weeks treatment in glomerular filtration rate. Timeframe: Inclusion of patients from february 2024. Last visit september 2025. Presentation spring 2026, publication fall 2026.
To compare between Transcranial Ultrasound , MRI and CT in patients with Hypoxic Ischemic Encephalopathyas regards diagnostic accuracy and prognostic value .
In today's medical field, there is a growing emphasis on the development of functional and molecular imaging. Therefore, it has significant technical limitations. To address this issue, this project aims to develop a high-speed multimodal photoacoustic/ultrasound functional imaging system that provides both structural and functional information of tissue and organs, thus enhancing the accuracy of early screening and diagnosis of neonatal cranial lesions. This imaging technology is entirely non-invasive and does not involve ionizing radiation or contrast agents. Products using the same technology have already received FDA approval and entered clinical use in the United States. We develop a new generation of multimodal photoacoustic/ultrasound functional imaging equipment to reveal the physiological characteristics and structural details of neonatal cranial lesions, offering advantages and complementary information compared to traditional medical imaging methods.
Warfighter Performance Optimization in Extreme Environments remains an area of important and intense investigation, with the following goals: (1) Optimize, sustain and augment medical readiness and physiological/ psychological performance in extreme and hazardous military operational environments and (2) develop joint DoD countermeasures and guidance to sustain performance, assess physiological status, and reduce injury risk in extreme and hazardous operational environments. Successful and safe outcomes in extreme and hazardous operational environments require that warfighters maintain optimum cognitive and exercise performance during physiologic stress. Extreme environmental conditions encountered in such environments include warfighter exposure to hypoxia and hypothermia, alone or in combination. Both hypoxia and hypothermia undermine O2 delivery system homeostasis, imposing dangerous constraints upon warfighter cognitive and exercise capacity. While red blood cells (RBCs) are commonly recognized as O2 transport agents, their function as a key signaling and control node in O2 system delivery homeostasis is newly appreciated. Through O2 content-responsive modulation of RBC energetics, biomechanics, O2 affinity and control of vasoactive effectors in plasma - RBCs coordinate stabilizing responses of the lung, heart, vascular tree and autonomic nervous system - in a fashion that maintains O2 delivery system homeostasis in the setting of either reduced O2 availability (hypobaric hypoxia) or increased O2 demand (hypothermia). Human RBCs demonstrate adaptive responses to exercise, hypoxia and hypothermia - these changes are commonly appreciated as a key element enabling high altitude adaptation. However, under conditions of hypoxia and hypothermia, without prior adaptation, RBC performance is adversely impacted and limits the dynamic range of stress adaptation for O2 delivery homeostasis - therefore limiting warfighter exercise capacity and cognitive performance in extreme environments, such as during acute mountain sickness.
The POWERbreathe™ Plus: an Inspiratory Muscle Training device (IMT) with adjustable resistance. Intervention lasts 4 weeks, with a frequency of 6 days/week, 2 series of 30 inspirations in the morning and evening. Resistance based on 60% of the Pressure Maximal Inspiratory (PMI). Progressive increase in resistance every week. Four laboratory visits: 2 pre-tests and 2 post-tests. Each pre- / post- test will go under normoxic and hypoxic conditions. Measurements include Pulmonary functions (spirometry test); blood microcirculation (vascular occlusion test); gas exchanges (e.g. VO2max), cardiac parameters, heart rate variability, maximal aerobic power (incremental and time limit test)
Tumor hypoxia is one of the physiological factors for treatment resistance and likely contributes to poor overall survival among patients with head and neck cancer (HNC). Identifying hypoxic features of HNC may allow the personalizing treatment plan. The investigators propose multiparametric Hypoxia MR (HMR) imaging using diffusion, perfusion, and oxygenation as non-invasive, in-vivo imaging components of a hypoxia phenotype. Assessing the hypoxia phenotypes' expression will be critically important for characterizing and predicting CRT response among patients with advanced HNC. A prospective cohort study will be conducted used multiparametric MR (MPMR) imaging correlated with treatment response assessed by 3 months fluorodeoxyglucose-positron emission tomography (FDG-PET). The image analysis approach will be developed to incorporate FDG-PET and quantitative MRI characteristics of tumor (ADC, oxygen-enhanced T1 and T2* maps, and volume transfer constant (Ktrans) to facilitate 3D visualization of multiparametric information. This proposed study's overarching goal is to develop and validate multiparametric HMR imaging using 18F - (fluoromisonidazole) FMISO-PET and immunohistochemistry (IHC) as the standard of references.
The oximeter is used to monitor intensive care patients undergoing oxygen therapy. It indicates pulsed oxygen saturation (SpO2), a reflection of arterial oxygen saturation (SaO2) which enables detection of hypoxemia and hyperoxia, both deleterious state. Current SpO2 recommendations aim to reduce both risk of hypoxemia and hyperoxia. SpO2 is considered the 5th vital sign. Current recommendations for SpO2 targets do not consider the variability of oximeters used in clinical practice. This variability and lack of specification represent an obstacle to an optimal practice of oxygen therapy. Thus, this study aims to compare the SpO2 values of different oximeters (General Electric-GE, Medtronic, Masimo and Nonin) used in clinical practice with the SaO2 reference value obtained by an arterial gas in order to specify the precision and the systematic biases of the oximeters studied. This data will also make it possible to refine the recommendations concerning optimal oxygenation
Hypoxia represents the prevailing adverse occurrence during the sedation of patients undergoing gastrointestinal endoscopy with propofol. A recent innovation in this domain is the COMBO Endoscopy Oropharyngeal Airway-a multifaceted device that encompasses capnography monitoring, bite block , oxygenation support, and oropharyngeal airway management. This device has been purposefully designed to cater to the unique requirements of endoscopic procedures. The principal objective of our randomized study is to assess the efficacy and safety of the COMBO Endoscopy Oropharyngeal Airway reduce the incidence of hypoxia on patients undergoing gastrointestinal endoscopy under propofol sedation.