View clinical trials related to Hypoxia.
Filter by:Effects of acute intermittent hypoxia on brain function imaging and systemic inflammation Patients with obstructive sleep apnea (OSAS) may have neurological cognitive impairment. The reason is not clear. Intermittent hypoxia is one of the main manifestations of OSAS. The investigators hypothesize that acute intermittent hypoxia (AIH) can lead to abnormal metabolic activity in some regions of the brain, which may be associated with systemic inflammation. The investigators proposed in 12 to 15 cases of healthy volunteers, in the form of breathing in the nitrogen intermittently, were observed before and after AIH MRI diffusion tensor imaging (DTI) changes in brain regions and at the same time understand the inflammatory factors and the change of oxidative stress in the human body. The investigators look at the data from different brain regions of the brain DTI anisotropic score (FA), radial diffusion coefficient (RD), axial diffusion coefficient (AD) and peripheral blood interleukin-6 (IL - 6), interleukin-8 (IL - 8), interleukin-10(IL - 10), tumor necrosis factor alpha (TNF-α), Interleukin-1 beta (IL-1β), Leptin, high sensitivity reactive protein(hsCRP), Intercellular Adhesion Molecule 1(ICAM 1),Vascular cell adhesion protein 1(VCAM-1) , E-selectin, endothelin-1(ET - 1), 8-iso-PGF2α,3-nitrotyrosine(3-NT),hypoxia-inducible factor 1α(HIF 1α). Statistical data processing includes: the matching t test of the above indicators before and after AIH; The relationship between DTI and peripheral blood inflammatory factors was analyzed by single factor. Using DTI as the dependent variable, the peripheral blood inflammatory factor was analyzed by multifactor correlation. Ultimately, the effect of AIH on the brain's regional functions will be understood, and whether the effect is related to systemic inflammation.
High Tidal volume is one of the main mechanisms that lead to lung injuries under mechanical ventilation (ventilator induced lung injury: VILI). It could also induce lung damage during spontaneous or assisted ventilation (patient-self inflicted lung injury: P-SILI). Different non invasive oxygenation devices are available to deliver oxygen during acute hypoxemic respiratory failure: high concentration mask, high flow nasal canula and non-invasive ventilation (with bucco-nasal mask or helmet). The investigators hypothesized that the device may influence the tidal volume. Therefore, the objective of this study is to measure and compare the tidal volume during the use of each device. Tidal volume will be measured using Electrical impedence tomography.
This is a study to validate the efficacy of using a small portable oxygen source to mitigate altitude-induced hypoxia.
A prospective double blind, placebo-controlled, randomized cross-over trial to evaluate the effect of lowering cerebral blood flow on the ventilatory chemoreflexes (acute hypoxic and hypercapnic ventilatory responses).
In general bronchoscopy is a safe procedure with low rate of complications. Indeed, contraindications to flexible bronchoscopy are mostly relative rather than absolute. This is the case of preexisting decreased blood oxygen levels which may be present in patients requiring further bronchopulmonary investigation. To avoid the deleterious effects of oxygen drops oxygen supplementation is recommended. The purpose of this study is to evaluate the efficiency and safety of oxygen supplementation obtained with the use of a high flow nasal cannula compared with a low flow nasal cannula during flexible bronchoscopy. Consecutive patients referred by their treating physician for bronchoscopy will be offered to take part in the study. Those who wish to participate and give their consent will be randomly assigned into one of two treatment groups (supplemental oxygen given via low flow nasal cannula or via high flow nasal cannula). Assignment to either treatment arm will not affect in any way the intended purpose of the bronchoscopy. All patients will be closely monitored during the procedure and 2 hours following its completion. Monitoring will be conducted, using strictly non-invasive measures.
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.
There is an increasing incidence of Necrotizing Enterocolitis (NEC) affecting the premature infant population, principally those with associated risk like extreme prematurity, extreme low birth weight, associated co-morbidities (Congenital heart disease, perinatal asphyxia) and those born in hospitals with limited resources for optimal neonatal care. Near Infrared Spectroscopy (NIRS), has been used in premature infants to evaluate changes in cerebral perfusion and oxygenation. (1) It provides real time insight into the oxygen delivery.(3) In the premature patient population, many neurologic injuries occur as a result of prenatal (pre-existing) and/or postnatal disturbance on oxygen delivery. NIRS has been focused in cerebral monitoring. Light easily penetrates through neonatal bone and skin tissue, and allows to monitor the subjacent oxygen content. Early studies were performed to validate NIRS measurements and have established normative data.(4-6) The non-invasive method of monitoring cerebral hemodynamics and oxygenation has revolutionized the intensive care units in patients at risk for neurological injuries. This method has been successfully validated to monitor neonatal cerebral oxygenation in different clinical settings and study protocols. (7) NIRS provides non-invasive, continuous information on tissue perfusion and oxygen dynamics. One of the biggest challenges of NEC spectrum diseases is in the making of early diagnosis. It is important to monitor not just cerebral perfusion but also the intestinal oxygenation.(8,9) Previous studies with NIRS have demonstrated that premature infants change their cerebral - splanchnic oxygenation ratios during feedings.(10) Guy et al. performed NIRS in premature piglets to demonstrate association of perfusion change with NEC spectrum(11,12); these studies suggest evidence that NIRS could be a useful diagnostic tool in the premature infant population trough abdominal NIRS (a-NIRS) measurement capable of detecting alterations in intestinal oxygenation and perfusion. In summary, a-NIRS could be use in the premature infant population to define reference values, especially in patients at risk, which would then facilitate the early diagnosis of NEC spectrum diseases.
For some upper ureteral and renal stones,ureteroscopic lithotripsy needs to be performed under general anesthesia with interrupted suspension of mechanical ventilation, which could result in hypercapnia and hypoxia. In this study, the investigators hypothesize that 10 cmH2O PEEP added to the respiratory circuit with 1 L/min 100% oxygen might extend the time of ventilation suspension but have no effect on carbon dioxide retention in blood.
Aim: To evaluate the influence of oxygen deficit on the cognitive performance and also about the architecture and sleep efficiency in volunteers subjected to mild and moderate exercise in a hypobaric chamber. SUMMARY: Participants in this study 30 healthy male volunteers, aged 20 to 40 years, regular physical activity, constituting three groups: 1 - without exercise-hypoxia group 10 volunteers who not be subjected to any kind of physical exercise in hypoxia and remain all day of experiment, 2 - group exercise at sea level, is composed of 10 volunteers who will undergo a protocol exercise physical sea-level, 3 - group exercise and hypoxia - 10 volunteers who will carry out a protocol exercise on a treadmill, being the same in condition of hypoxia (hypobaric chamber). All groups on the first day of the experiment will undergo baseline assessments, laboratory blood analysis salivary and spirometric testing. Assessments will be personality and neuropsychological. After baseline assessments, the last day of the experiment, the groups will be evaluated again 4350m above sea level the sea, by personality tests, neuropsychological and laboratory. RATIONALE AND BACKGROUND: During exposure to environments with a partial reduction of oxygen, human body can undergo several physiological and psychological changes are not prepared for such condition. Few studies have reported that the elevation changes and cognitive aspects related to sleep. MATERIAL AND METHOD: They describe the procedures to be performed, and the study conducted in local with adequate infrastructure.
The purpose of this study is to determine the feasibility, safety and effectiveness of an endotracheal tube embedded with a mini video-camera as a guiding tool for percutaneous tracheostomy.