View clinical trials related to Hypoxia.
Filter by:The purpose of this study is to evaluate how variations in oxygen demands may change heart electrical activity in individuals with and without oxygen dependence.
The primary objective of this project is to examine the efficiency of intermittent hypoxia-hyperoxia conditioning (IHHC) protocol to improve vascular health and reduce blood pressure in hypertensive patients (stage 1). The result of the present study will investigate if IHHC could be a therapeutic treatment for hypertensive individuals. The investigation is designed with a placebo intervention (air ambient) and a control group (age-matched healthy participants). The interest of short cycles of intermittent hypoxia-hyperoxia is due to the triggering of the vasodilatory response in a greater extent compared to the pressor mechanisms since the exposure duration remains short. Therefore, it can be hypothesized that control and hypertensive groups achieving IHHC may exhibit a decreased blood pressure compared to the control and hypertensive groups achieving placebo intervention. The control group may show greater change than hypertensive due to higher vascular reserve. The secondary objective of the study is to understand the underlying mechanism of the beneficial effects of IHHC, especially the role of blood hemorheological changes. Based on available literature, it is know that hypoxia induce an increase in blood viscosity. One may hypothesize that with such a short hypoxic dose used during IHHC, only minor change in blood viscosity may occur. However, a slight rise in blood viscosity is known to stimulate NO synthase and then to produce more NO. Hence it could be one of the mechanisms involved in the early vasodilatory response to hypoxia. These findings are in line with the reported higher NO end-product metabolites during exercise in normoxia and hypoxia in subjects who showed a rise in blood viscosity after exercise. The hypothesis is that the magnitude of IHHC beneficial effects is related to change in blood viscosity and its determinants.
High Flow Nasal Oxygen Therapy (HFNO) is a new oxygenation tool that is becoming increasingly widespread in perioperative anaesthesia. The benefits of this oxygenation tool are based on different physiological principles. These include the reduction of dead space by "flushing" the nasopharyngeal cavities, positive airway pressure and the warming and humidification of inspired air. In addition, the high flow rates used ensure that the patient's inspiratory demand is covered, allowing for the delivery of oxygen-enriched and controlled air. It is simple to use, with the only parameters to be set being gas flow and FiO2. The use of HFNO appears to allow a prolongation of apnoea time without desaturation in apneic ventilation. Mainly studied in ENT surgery because of the interest that this oxygenation strategy presents with the absence of recourse to oro-tracheal intubation (OTI), several authors will use it in the framework of micro-laryngoscopy surgery in suspension. However, its use as an oxygenation strategy during panendoscopy has been little explored. Panendoscopy is a common procedure that requires deep and short anesthesia. The main challenge is the sharing of the airway between the anesthesia team and the surgical team. Learning to use this new method or the impact of operator experience has never been explored.
Endotracheal intubation in infants often involves more than one attempt, and oxygen desaturation is common. It is unclear whether nasal high-flow therapy, which extends the time to desaturation during elective intubation in infants receiving general anesthesia, can decrease the occurence of desaturation during intubation. The investigators tested the hypothesis that high-flow nasal oxygen cannulae would be effective in maintaining oxygen saturation during intubation than facemasks for pre-oxygenation. The investigators randomly allocated 84 patients undergoing elective surgery aged <=12 months to pre-oxygenation using either high-flow nasal oxygen or facemask.
To determine whether a strategy of adding venovenous ECMO to mechanical ventilation, as compared to mechanical ventilation alone, increases the number of intensive care free days at day 60, in patients with moderate to severe acute hypoxic respiratory failure.
Obesity is associated with adverse airway events including desaturation during deep sedation. Previous studies have suggested that high-flow nasal oxygenation may be superior to regular (low-flow) nasal cannula for prevention of hypoxia during Sedated Gastrointestinal Endoscopy in non-obesity patients. The prerequisite of high-flow nasal oxygenation is keeping airway patency. Our pervious study demonstrated that nasopharyngeal airway has the similar efficacy of jaw-lift. In present study we aimed to determine whether high-flow nasal oxygenation combined with nasopharyngeal airway could reduce the incidence of hypoxia during Sedated Gastrointestinal Endoscopy in obese patients.
Infants are at risk of developing motor and cognitive neurodevelopmental disabilities as a sequelae to hypoxic-ischemic brain injury during the perinatal period. It is an ongoing challenge to predict the severity and extent of future developmental impairment during the neonatal period. This study will help test the feasibility of conducting a large-scale study that evaluates the role of diffuse optical tomography as a bedside neuroimaging tool in complementing the prognostic value of conventional and diffusion weighted MRI for predicting neurodevelopmental outcome in neonates with perinatal hypoxic-ischemic brain injury.
The objective of this study is to observe the preventive effects of high flow nasal oxygenation on the incidence of hypoxia during gastroscopy or colonoscopy sedated with propofol in high-risk patients.
Fetal heart rate (FHR) monitoring during labor aims to detect fetuses at risk of intrapartum hypoxia in order to accelerate their birth before the constitution of sequelae such as anoxic encephalopathy and cerebral palsy. But the positive predictive value of FHR monitoring is low, and many second-line tests have been proposed but none of them has been proven to be conclusive. Measure of placental elasticity and viscosity during labor could be a new second line test to complete the FHR monitoring. Several studies have shown that placental elasticity is increased in case of gestational diabetes, preeclampsia, or intrauterine growth restriction, but no study has focused on placental elasticity during labor. The investigators hypothesize that placental elasticity and viscosity could reflect the quality of maternal-fetal exchanges during labor, and could help to detect fetus at risk of intrapartum hypoxia. The first aim of this study is to describe the values of placental elasticity and viscosity during different points in the labor: beginning of the labor, beginning of the active phase of the first stage of labor, and passive phase of the second stage of labor. Secondary aims of this study are: to describe the values of placental elasticity and viscosity in case of oxytocin infusion, in case of abnormal FHR, and ex-vivo after placental expulsion. This unicentric observational prospective study will include 150 patients with singleton pregnancy, without pathology, with spontaneous labor at term.
This study is designed to evaluate the role of Oxygen Enhanced (OE) Magnetic resonance imaging (MRI) and Blood Oxygenation Level Dependent (BOLD) MRI in detecting regions of hypoxic tumour and to evaluate their use as imaging methods to selectively deliver targeted radiotherapy to regions of aggressive disease.