View clinical trials related to Hyperoxia.
Filter by:Oxygen therapy is the most common treatment modality for patients with hypoxemia, but target values for normoxemia are not clearly defined. Therefore, iatrogenic hyperoxemia is a very common situation. Even though there are many side effects reported related to hyperoxemia and hyperoxemia is shown to be related to worse outcome than expected; clinicians still observe hyperoxemia frequently. Oxygen reserve index (ORi™) (Masimo Corp., Irvine, USA) can guide clinicians in detection of hyperoxia. ORi is a parameter which can evaluate partial pressure of oxygen (PaO2) rating from 0 to 1. There are growing evidences in ORi that it might be helpful to reduce hyperoxia in general anesthesia. Continuous ORi monitoring can be used for detecting and preventing hyperoxia. The ability to perform FiO2 titration with ORi may be an appropriate monitoring management to prevent the harmful effects of hyperoxia.In this study, in patients who underwent major abdominal surgery; It was aimed to investigate the effectiveness of ORi-guided FiO2 titration in preventing hyperoxia.
Chronic respiratory diseases are a global burden. Treatment options have improved in recent years, pulmonary rehabilitation plays a key role. Oxygen therapy is recommended in patients with a low saturation at rest, but no clear guidance is given for patients who desaturate during exercise. The effect of ambulatory oxygen during exercise is not yet completely understood, especially in those patients with exercise-induced desaturation. Aim: The goal of this study is to analyse the effect of supplemental oxygen given during a constant work rate exercise test (CWRET) on a cycle ergometer compared to sham air. Methods: We plan to include 25 Patients respiratory patients undergoing pulmonary rehabilitation (male and female; aged >18 years; stable condition >3 weeks (e.g. no exacerbations); resting oxygen saturation (SpO2) ≥ 88%) with exercise induced hypoxemia defined by a fall in oxygen saturation by ≥ 4% during a 6-minute walking test. Patients will undergo an incremental exercise test with a ramp protocol (for evaluating the maximal workload) and two CWRET (75% of the maximal workload) with ambulatory oxygen or placebo (sham air) via standard nasal canula at a flow rate of 5l/min. Patients and assessors will be blinded. The difference endurance time of the CWRET with oxygen vs. sham air will be the primary outcome of this study. Data will be summarized by means (SD) and medians (quartiles) for normal and non-normal distributions. Effects of treatment will be evaluated by mean differences with 95% confidence intervals, T-tests or Wilcoxon matched pair tests as appropriate. A p-value threshold of <0.05 or a confidence interval not including zero will be considered as statistically significant. Analyses will be performed according to the intention to treat principle.
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.
The aim of this study is to evaluate the impact of the FreeO2 system on the quality of the oxygen therapy in confirmed or suspected SARS-CoV-2 patients in the emergency department.
The purpose of this study is to find out a serum marker for the evaluation of blood brain barrier damage based on animal experiments and investigate the effect of NBO（Normobaric hyperoxia）on blood brain barrier in the acute ischemic stroke patients who received r-tPA thrombolytic therapy.
Aim of the present study is to investigate the influence of hyperoxia on the protein expression using the differential analysis of protein expression in tissues (proteomics). In the study, blood and urine samples will be collected from participants who undergo a short term hyperoxia using 100% oxgen for 3 hours. Here, gel electrophoresis, protein separation and mass spectroscopy allow to identify affected proteins. Based on these results, different induction factors of proteins will be determined and then assessed using a bioinformatic network analysis regarding the cellular influence.
We made a fortuitous observation of periodic breathing in a healthy subject coming to our outpatient mountain medicine consultation at Avicenne hospital in Bobigny (France). During this consultation, subjects perform a hypoxia exercise test, which allows a good prediction of their risk factors for severe high altitude illnesses. Surprisingly, breath-by-breath recording of the ventilation signal showed a periodic breathing pattern, which increased when the subject started to exercise in hypoxic conditions and was maintained during normoxic exercise. Therefore, our objective was to confirm this observation in a retrospective study led in 82 subjects who passed this test. We tested the hypothesis that subjects with a brisk ventilatory response to hypoxia might show a more pronounced periodic pattern of ventilation, due to a higher gain of the chemoreceptor feedback loop. Then, our objective is to investigate the mechanisms involved in the periodic pattern in healthy subjects, as a function of exercise intensity, altitude intensity, role of peripheral and central chemoreceptors to O2 and CO2. Finally, we want to investigate the possible role of this ventilatory instability in patients with obstructive or central apneas.
The purpose of this study is to determine how intraocular pressure responds to changes in the levels of carbon dioxide or oxygen that a healthy individual inspires.