View clinical trials related to Hypoxia.
Filter by:The intent of this study is to determine the difference in pharyngeal oxygen concentration in patients who have a natural airway (not intubated) using commonly available oxygen delivery systems. The investigators will test the hypothesis that oxygen concentration during the period of inspiration (FiO2) in the pharynx is dependent on oxygen delivery system design, even at high flow (15 liters/minute) oxygen delivery. Specific measurements include oxygen concentration at subjects' lips and pharynx when breathing 100% oxygen and room air via a simple mask, non-rebreather mask, OxyMaskTM, and anesthesia mask with headstrap and Jacson Rees circuit. A mean difference of 10% pharyngeal FiO2 between any of the masks will be considered clinically important. The expected standard deviation of the within-subject FiO2 is 3.5%. With a significance criterion of 0.05, 10 subjects would provide more than 90% power to detect a mean difference of 10%.
Dysfunctional adipose tissue predisposes to cardiovascular disease. Similarly, the risk of cardiovascular disease appears to be increased in subjects with obstructive sleep apnoea. Reduced adipose tissue oxygen availability has been described in obesity and may also be a mechanism in obstructive sleep apnoea. Hypoxia induces inflammation and fibrosis in adipose tissue which are factors contributing to cardiovascular risk. The investigators hypothesize that adipose tissue's oxygen uptake is reduced in subjects with obstructive sleep apnoea by comparing in vivo AT oxygenation and blood flow in tissue of control subjects.
The purpose of this study is to determine if 2 weeks of nightly exposure (7-12 hours per night) to moderate hypoxia (~2,400 meters or 7,500 feet) improves glucose metabolism in people with type 2 diabetes.
Hemodialysis patients may experience drops in blood oxygen saturation during the hemodialysis treatment, which may lead to hypoxia in the tissues. The investigators hypothesize that: 1. The cumulative number, severity, or other characteristics of such deoxygenation episodes may be a predictor of adverse outcomes in hemodialysis patients. 2. There may be demographic, anthropometric, clinical, treatment prescription, lab analytical, and other parameters that correlate with the number and severity of deoxygenation episodes and, therefore, may be used for risk stratification. Further, some of these parameters may be modifiable.
The purpose of the study is to compare the intratumoral biodistribution of FAZA and F-miso in patients with non-small cell lung cancer and correlate the results of PET scans with immunohistochemistry.
The primary objective of this research is to measure changes in neurochemical concentrations during stimulation of the primary visual cortex, in both conditions of normoxia (normal oxygen availability) and induced mild hypoxia (reduced oxygen availability).
Study to evaluate the %SpO2 accuracy performance of the Nonin Medical pulse oximetry systems.
Glioblastoma multiforme (GBM) is the most common primary malignant brain neoplasm in adults. Despite recent diagnostic and therapeutic advances, including aggressive surgical resection and chemoradiation, the prognosis of GBM has improved only slightly over the past two decades, with median survival of approximately 15 months. Tumor hypoxia is a feature of GBM that contributes to poor outcome through multiple mechanisms such as 1) overexpression of enzymes that play roles in temozolomide resistance, the main chemotherapeutic agent in GBM and 2) increase expression of cancer stem cells which are more resistant to radiation. Hypoxic tumour regions are associated with higher rates of progression and recurrence. In this study the investigators will use an advanced MRI technique called qBOLD to non-invasively measure oxygenation in GBM and obtain targeted biopsies. The investigators take advantage of physical characteristics of Ferumoxytol (Feraheme®) which is an iron supplement, and utilize two recent technical advances not previously used in human tumours to quantitatively measure oxygenation in GBM. Prior knowledge of hypoxia can assist in prognostication and individualization of treatment planning with special focus on hypoxic regions by targeted radiation dose or regimen modulation; consideration of more intensive chemotherapy regimens; more aggressive and targeted surgical resection and closer short-term clinical and imaging follow-ups.
Airway placement after anesthetic induction in pediatric patients is routinely performed at our institution without apneic oxygenation. When intubation is attempted by an inexperienced (learner) provider, the attending physician intervenes if necessary before the patient experiences excessive loss of oxygenation. The investigators plan to institute routine supplemental oxygenation via nasal cannula during this placement. This study will examine the effect of adding apneic oxygenation via nasal cannula on oxygen saturation.
Every day in Ghana, 47 babies are stillborn (SB) and 232 babies are born with low birth-weight (LBW) - many of whom will die in infancy or suffer lifelong consequences. Sleeping on the back during pregnancy has recently emerged in scientific literature as a potential risk factor for SB and LBW. In fact, one of the earliest studies to demonstrate this link was conducted in Ghana by investigators on this protocol. When a woman in mid-to-late-pregnancy lies on her back, her large uterus compresses one of the major veins that delivers blood back to her heart and may completely obstruct it. This may result in less blood being returned to her heart and less blood being pumped to her developing fetus. Such changes may negatively impact the growth of her fetus and, along with some other risk factors, may contribute to the death of her baby. The investigators have developed a device, 'PrenaBelt', to significantly reduce the amount of time a pregnant woman spends sleeping on her back. The PrenaBelt functions via a simple, safe, effective, and well-established modality called positional therapy. The purpose of this study is to determine the effect of the PrenaBelt on birth-weight and assess the feasibility of introducing it to Ghanaian third-trimester pregnant women in their home setting via an antenatal care clinic and local health-care staff. Data from this study will be used in effect size calculations for the design of a large-scale, epidemiological study targeted at reducing LBW and SB in Ghana and globally.