Active clinical trials for "Hypoxia"

This study is a pharmacodynamic proof of concept study investigating the physiological effects of systemic infusion of nitrite on coronary blood flow using MRI.

An open-label, randomised, Best-Available-Care (BAC) and historic-controlled trial of nebulised dornase alfa [2.5 mg BID] for 7 days in participants with COVID-19 who are admitted to hospital and are at risk of ventilatory failure (the COVASE study). Controls will include a randomised arm to receive BAC, historic data from UCLH patients with COVID-19 and biobanked samples will be used to demonstrate an effect of dornase alfa. CRP will be measured to assess the effect of dornase alfa on inflammation. Clinical endpoints and biomarkers (e.g. d-dimer) will be used to assess the clinical response. Exploratory endpoints will explore the effects of dornase alfa on features of neutrophil extracellular traps (NETs).

Brain tumor surgery is commonly associated with different degrees of preoperative intracranial hypertension and surrounding tumor edema, elicited by tumor underlying pathophysiology. During craniotomy for brain tumor resection maintenance of hemodynamic stability and intracranial homoeostasis is of paramount importance. Disordered hemodynamics or adverse stress may activate the immune inflammation or neuroendocrine responses and lead to a surge of inflammatory mediators and stress hormones, which are implicated in secondary brain insults. Adverse physiological responses caused by intraoperative disordered hemodynamics or surgery-related damage, may lead to some secondary brain injury (such as cerebral edema or cerebral hemorrhage), aggravating damage to brain tissue and affecting the recovery from anesthesia, cognition and prognosis in patients. Prevention of secondary brain injury is a key-endpoint to improve clinical outcomes in glioma patients undergoing craniotomy. Alpha2-adrenoceptor agonists have been widely used for sedation, analgesia and anti-sympathetic actions for many years, but the definite evidence of their potential use as neuroprotectants has so far been confined to animal studies, yet the findings are inconsistent. Dexmedetomidine (DEX) has been demonstrated to be a new type a2 adrenergic receptor (a2-AR) agonist, which can selectively bind with the a1 and a2 adrenergic receptor, and playing a dual role by restraining the activity of sympathetic nervous and stimulating the vagus nerve. Dexmedetomidine (DEX) also plays an important role in in inhibiting inflammatory and neuroendocrine responses. Animal experiments showed that the right must have a dexmedetomidine neuro-protective effect. However, the brain-protective effect of dexmedetomidine in anesthesia of craniotomy resection of glioma has not been reported. Thus, the aim of this study was to explore the effect of dexmedetomidine on perioperative brain protection, as well as cerebral oxygenation and metabolic status aiming to provide a basis for clinical rational drug use in patients undergoing craniotomy resection of glioma.

In this current study, the examiners examine some of the mechanisms of how Acute Intermittent Hypoxia (AIH) effects the upper extremity of survivors of spinal cord injury. This is accomplished both with the use of a load cell to determine elbow strength changes and high density grid electromyography (EMG) to record bicep muscle activations before and after bouts of AIH

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.

A feasibility study to determine if it is possible to perform a safe, adequately powered, and affordable multi-centre study in critically ill children comparing current practice of liberal targets for systemic oxygen levels with more conservative targets.

Cardiac surgery with cardiopulmonary bypass (CPB) frequently induces post-operative respiratory dysfunction. The post-operative pulmonary complications (PPCs) significantly increase the peri-operative morbidity and require invasive treatments during longer and more expensive ICU stays. A specific pathophysiology involving general anesthesia and CPB-related factors (inflammation, pulmonary ischemia) has been clearly demonstrated and pulmonary atelectasis seems to play a central role in the occurence of these PPCs. The open lung approach is a ventilation strategy that aims to "open the lung and keep it open" using different ventilatory settings. The efficacy of that strategy is not demonstrated in the global surgical population. However, its application in the perioperative care of cardiac surgery patients could be of great interest by counteracting the development of atelectasis. The purpose of this multicentre, double blinded, randomized controlled study is to evaluate the influence of a perioperative multimodal protective ventilation strategy based on the "open lung approach" on postoperative outcomes during the first 7 days following cardiac surgery. Participating centres will include 500 adult patients undergoing scheduled on-pump cardiac surgery. The open lung approach will combine recruitment maneuvers (RM), positive end expiratory pressure (PEEP) at 8 cmH2O from intubation to detubation and continuation of ultraprotective ventilation during CPB. It will be compared to a conventional approach without RM, with PEEP at 2 cmH2O and discontinuation of ventilation during CPB. The primary endpoint is any post-operative pulmonary complication. The secondary endpoints are any post-operative extra-pulmonary complications and the number of ICU-free days to day 7.

High-flow nasal cannula (HFNC) that uses heated and humidified oxygen was recently introduced for bedside care. It has been shown to be associated with reduced risks of tracheal intubation rates and mortality in adult hypoxic patients. The mechanisms of the effects of HFNC are thought to be related to the favorable effects of the heated and humidified gas, the high-flow rate used to minimize the entrainment of room air, and an increase in the ventilation efficiency, including the elimination of nasopharyngeal dead space, positive end-expiratory pressure (PEEP) effects, and improvements in paradoxical abdominal movement. Regarding the effects on lung volume, global ventilation in the lungs increases during HFNC, which is thought to attribute to PEEP effects. However, how regional ventilation is affected during HFNC in comparison with conventional NC remains unknown. Because PEEP in mechanically ventilated patients improves the regional homogeneity of ventilation, investigators postulated that HFNC via PEEP effects would result in more homogeneous regional distributions in the ventilation changes. Investigators therefore assessed global and regional ventilation in patients with hypoxia receiving care via HFNC using electric impedance tomography and compared these results with conventional nasal cannula.

Regulation of tissue oxygen homeostasis is critical for cell function, proliferation and survival. Evidence for this continues to accumulate along with our understanding of the complex oxygen-sensing pathways present within cells. Several pathophysiological disorders are associated with a loss in oxygen homeostasis, including heart disease, stroke, and cancer. The microenvironment of tumors in particular is very oxygen heterogeneous, with hypoxic areas which may explain our difficulty treating cancer effectively. Prostate carcinomas are known to be hypoxic. Increasing levels of hypoxia within prostatic tissue is related to increasing clinical stage, patient age and a more aggressive prostate cancer. Several researches indicated that hypoxia might also play a role in esophageal cancer. In glial brain tumors, hypoxia is correlated with more rapid tumor recurrence and the hypoxic burden in newly diagnosed glioblastomas is linked to the biological aggressiveness. In brain metastases CA-IX expression (a marker for hypoxia) is correlated to the primary non-small cell lung carcinomas. Hypoxia enhances proliferation, angiogenesis, metastasis, chemoresistance and radioresistance of hepatocellular carcinoma. The hypoxic markers HIF-1α, VEGF, CA-IX and GLUT-1 were all over expressed in colorectal cancer and its liver metastases. Based on literature, hypoxia in tumors originating or disseminated to prostate, esophagus, brain and rectum cancer will be studied in this trial.

The investigators hypothesize that the administration of two widely available, naturally occurring dietary supplements, 5 hydroxytryptophan and creatine monohydrate, will reduce the severity of depression in individuals exposed to chronic hypoxia by living at altitude. The purpose of this study is to determine if 8 weeks of dietary augmentation with oral 5 g creatine daily and 100 mg 5-HTP twice daily reduces hypoxia-related depressive symptoms measured by the 17-item Hamilton Depression Rating Scale (HAM-D) in women with SSRI or SNRI-resistant depression.