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.
The goal of this clinical trial is to learn about the mechanisms of oxygen toxicity in scuba divers. The main questions it aims to answer are: - How does the training of respiratory muscles affect oxygen toxicity? - How do environmental factors, such as sleep deprivation, the ingestion of commonly utilized medications, and chronic exposure to carbon dioxide, impact the risk of oxygen toxicity? - How does immersion in water affect the development of oxygen toxicity? Participants will be asked to do the following: - Undergo a basic screening exam composed of health history, vital signs, and some respiratory function tests - Train their respiratory muscles at regular intervals - Exercise on a cycle ergometer both in dry conditions and underwater/under pressure in the context of medication, sleep deprivation, or carbon dioxide exposure Researchers will compare the performance of each subject before and after the possible interventions described above to see if there are changes in exercise performance, respiratory function, cerebral blood flow, and levels of gene expression.
The goal of this RCT is to demonstrate that, in neonatal anesthesia, the use of Lung Ultrasound (LUS) to guide choice of best Positive End-Expiratory Pressure (Peep) - the one that efficiently avoids lung atelectasis - leads to better gas exchange in the lung thus can lead to reduction of FiO2 applied to ventilatory setting in order to achieve same peripheral saturations of oxygen (SpO2). Specific aims of the study are: 1. to determine if LUS-guided PEEP choice in neonatal anesthesia, compared to standard PEEP choice, can lead to reduction of FiO2 applied to the ventilatory setting in order to maintain same SpO2s. 2. to determine if patients treated with LUS-guided PEEP will develop less postoperative pulmonary complications in the first 24 hours. 3. to compare static respiratory system compliance between groups. 4. to determine if there is a significant difference in hemodynamic parameters and amount of fluids infused or need for vasopressors between the two groups.
Finger pulse oximetry SpO2 is widely used to estimate arterial oxygen saturation SaO2. Current Spo2 targets do not take into consideration the many variables that affect that correlation in particular skin pigmentation. This study aims to evaluate different FDA approved pulse oximeters (Nonin co-pilot, massimo Radical 7, Philips-standard of care monitor, innovo premium iP900BP, nellcor PM1000N, Nano100) with SaO2 reference values obtained by an arterial blood gas in subjects with different skin pigments measured by a skin color scale as well as self-identification of race.
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.
In patients under general anesthesia, the oxygen level (FiO2) used in inspiration is usually adjusted by monitoring the peripheral oxygen saturation level (SpO2). As a non-invasive method, SpO2 monitoring is known as one of the required methods that can be used to adjust FiO2 and detect and treat hypoxemia. While SpO2 approaching 100% matches the value of 128 mmHg in arterial partial oxygen pressure (PaO2), in cases where PaO2 increases more, the investigators cannot follow this situation with SpO2 and cannot prevent hyperoxemia. As stated in the literature, hyperoxemia has positive effects in general anesthesia and intensive care, as well as negative effects such as increased inflammation, oxidative stress and ischemia-reperfusion. In addition, acute lung injury, development of atelectasis, increased mortality, and critical illness rates have been associated with hyperoxemia in many publications. The only way the investigators can use to measure the level of hyperoxemia seems to be arterial blood gas analysis, and this method limits the investigators use because it is invasive. The Oxygen Reserve Index (ORi™) (Masimo Corp., Irvine, CA, USA) is a variable related to real-time oxygenation reserve status in the mildly hyperoxemic range (approximately 100 - 200 mmHg PaO2). ORi can be defined as a multi-wavelength, noninvasive pulse co-oximetry sensor. ORi is a dimensionless index ranging from 0.00 (no reserve) to 1.00 (maximum reserve) depending on the oxygenation reserve status. There are very few studies in the literature using ORi to detect hyperoxemia. The investigators thought that if FiO2 levels used in preoxygenation, anesthesia maintenance and recovery stages in day surgeries were correlated with ORi levels, a threshold value could be determined for FiO2 levels during anesthesia stages in cases where invasive arterial blood gas could not be followed. This study aims to determine the relationship between SpO2, FiO2 and ORi during general anesthesia, to investigate the usefulness of ORi in determining the FiO2 threshold value during anesthesia stages as an indicator of hyperoxemia, and to investigate the effects of these values on the hemodynamics, recovery, agitation and nausea-vomiting states of the patients.
This proof-of-principle study will determine if breathing an increased concentration of oxygen above the concentration in normal room air results in changes in the sensory and motor function in people with subacute or chronic, severe spinal cord injury (SCI).
Oxygen is the most commonly administered therapy in critical illness. Accumulating evidence suggests that patients often achieve supra-physiological levels of oxygenation in the critical care environment. Furthermore, hyperoxia related complications following cardiac arrest, myocardial infarction and stroke have also been reported. The underlying mechanisms of hyperoxia mediated injury remain poorly understood and there are currently no human in vivo studies exploring the relationship between hyperoxia and direct pulmonary injury and inflammation as well as distant organ injury. The current trial is a mechanistic study designed to evaluate the effects of prolonged administration of high-flow oxygen (hyperoxia) on pulmonary and systemic inflammation. The study is a randomised, double-blind, placebo-controlled trial of high-flow nasal oxygen therapy versus matching placebo (synthetic medical air). We will also incorporate a model of acute lung injury induced by inhaled endotoxin (LPS) in healthy human volunteers. Healthy volunteers will undergo bronchoalveolar lavage (BAL) at 6 hours post-intervention to enable measurement of pulmonary and systemic markers of inflammation, oxidative stress and cellular injury.
The aim of this study is to identify and determine the levels of oxidized lipids and lipid mediators following exposure to oxygen supplementation during mechanical ventilation by oxidative lipidomics. The investigators will include patients with mechanical ventilation and have received FiO2=>0.5 atleast 90 minutes and collected two sequential mini bronchoalveolar lavage on them 24 hours apart. Mass Spectrometry Lipid chromatography will be conducted and clinical data will be analyzed.
Normoxia Hyperoxia (NBO) is a neuroprotective approach that can be implemented early. NBO is simple and non-invasive and can be used at home or in an ambulance to ensure the shortest possible time after cerebral ischemia occurs. The previous study by the investigators suggested that NBO therapy in the early stage of cerebral ischemia has a neuroprotective effect on ischemic brain injury. Although the neuroprotective effect of NBO has been demonstrated, the optimal duration of treatment for NBO to exert neuroprotective effect is still unclear. Therefore, further discussion of the duration of NBO treatment will contribute to the clinical application of NBO and provide a definite theoretical basis for the treatment of cerebral infarction.