View clinical trials related to Hypoxia.
Filter by:During exercise in conditions of low oxygen (termed hypoxia), such as mountaineering at high altitudes, the lung blood vessels constrict in an attempt to protect the body from the negative effects of hypoxia. It appears that this blood vessel constriction may limit the heart to pump blood during heavy exercise, leading to reductions in exercise performance. Inhaled nitric oxide is a drug that is known to relax the lung blood vessels. Inhaled nitric oxide has been used to relax lung blood vessels and improve exercise capacity in patients with chronic disease. It is unknown if similar improvements would be observed during exercise in healthy individuals when exposed to low levels of oxygen. The goal of this study is to determine if inhaled nitric oxide can relax the lung blood vessels and improve the heart's pumping ability during exercise in low oxygen conditions. Further, the investigators will determine if these improvements in lung blood vessel and heart function increase exercise performance. Participants will complete 6 sessions over a three week period where they will perform exercise challenges while breathing low levels of oxygen with and without inhaled nitric oxide. The low oxygen conditions will be comparable to being at an altitude of 14,000-17,000 feet. 17,000 feet would be equivalent to standing on the summit of King Peak in the Yukon (the 4th tallest mountain in Canada).
Treatment of O2 naïve patients with PAH will be included in this investigator-initiated trial (IIT) to assess efficacy and safety of oxygen substitution. Nocturnal oxygen substitution improved the 6MWD compared to placebo in one clinical trial in PAH patients. Due to the positive results in the treatment of patients with PAH, the initiation of this proof-of-concept study is justified.
Background: Inhibiting the sodium-glucose cotransporter-2 (SGLT2) has been observed to reduce risk of cardiovascular events and kidney failure in type 2 diabetes. The exact mechanisms of the beneficial effects of SGLT2 inhibition (SGLT2i) are still unknown. Kidney hypoxia has been demonstrated in diabetic kidney disease and SGLT2i is thought to relieve hypoxia in the kidneys. Mitochondrial dysfunction and autonomic dysfunction might also contribute to kidney hypoxia. Objective: The primary aim of the study is to assess the acute effects of SGLT2 inhibition on parameters reflecting oxygenation and oxygen consumption of the human kidney in persons with type 1 diabetes. Exploratory aims are to investigate acute changes in oxygen availability and oxygen access to the kidneys after SGLT2i. This include measures of peripheral blood oxygenation, mitochondrial function and autonomic function. Methods: Acute intervention study with oral dapagliflozin given in two doses each of 50 mg or matching placebo as intervention. Kidney oxygenation and perfusion parameters will be assessed by blood-oxygen-dependant level magnetic resonance imaging. Mitochondrial function will be assessed by extracellular flux analysis on lymphocytes. Autonomic function will be assessed by measuring baroreflex sensitivity. Design: Randomized, double blinded, placebo-controlled, cross-over intervention study. Study population: Fifteen healthy controls are recruited by advertisement and 15 patients with type 1 diabetes recruited from Steno Diabetes Center Copenhagen. Endpoints: Primary end-point: Renal cortical and medullary oxygenation (T2*). Exploratory end-points: Renal cortical and medullary perfusion, renal artery flow, renal oxygen consumption, peripheral capillary oxygen saturation (SpO2), arterial oxygen partial pressure (PaO2), arterial oxygen saturation (SaO2), lymphocyte mitochondrial function, baroreflex sensitivity. Timeframe: Inclusion of patients from January 2020. Last patient last visit January 2021. Data analysis completed spring 2021, presentation autumn 2021 and publications Winter 2021.
Intermittent episodes of hypoxemia and/or bradycardia, also defined as cardio-respiratory events (CRE) are very frequent in preterm infants and may result in transient hypoxia and hypoperfusion of target organs, with possible clinical implications. The hemodynamic instability that characterizes the first 72 hours of life, also called as transitional period, place preterm infants at high risk of complications and may contribute to enhance fluctuations in end-organ perfusion and oxygenation induced by CRE. In this study we aimed to explore cardiovascular and cerebrovascular changes determined by different CRE types in preterm infants during the transitional period.
Most premature babies require oxygen therapy. There is uncertainty about what oxygen levels are the best. The oxygen levels in the blood are measured using a monitor called a saturation monitor and the oxygen the baby breathes is adjusted to keep the level in a target range. Although there is evidence that lower oxygen levels maybe harmful, it is not known how high they need to be for maximum benefit. Very high levels are also harmful. Saturation monitors are not very good for checking for high oxygen levels. For this a different kind of monitor, called a transcutaneous monitor, is better. Keeping oxygen levels stable is usually done by nurses adjusting the oxygen levels by hand (manual control). There is also equipment available that can do this automatically (servo control). It is not known which is best. Studies of automated control have shown that infants spend more time within their intended target oxygen saturation range. These have not included measurements of transcutaneous oxygen. The investigators aim to show the transcutaneous oxygen levels as well as the oxygen saturation levels when babies have their oxygen adjusted manually or automatically.
The aim of this study to evaluate the patients who underwent controlled hypotensive anesthesia under standardized depth of anesthesia; preoperative and postoperative blood HIF 1a, TAS, TOS measurement and cerebral perfusion evaluation with NIRS and to investigate tissue hypoxia secondary to hypotensive anesthesia and the changes of the mediators at the tissue level and which blood pressure parameters are related.
the study is conducted on hypoxic adult patients underwent open heart surgery after arrival to the intensive care unit and stabilization of patients' hemodynamics to assess the efficacy of transalveolar pressure measurement as an index for lung recruitment.
The purpose of this study is to identify patient and provider-chosen factors that put patients at risk for the development of hypoxemia (oxygen saturation < 90% for 5 seconds) during endoscopy and to use this knowledge to develop a treatment protocol for specific causes of hypoxemia in adult esophagogastroduodenoscopy outpatients.
Sleeping under hypoxic conditions can impair cognition and autonomic nervous activity. A short daytime nap can modify these changes. Here we propose a randomized, cross-over study to evaluate the heart rate variability during a 90 min nap in a normobaric hypoxic chamber. In addition, we will investigate sleep architecture, vigilance, attention and memory.
The study aims to evaluate the effects of acute hypobaric hypoxia on cognitive performance (H0: cognitive performance at 200 meters above sea level (asl) = cognitive performance at 3000 meters above sea level = cognitive performance at 5000 meters above sea level). Before participating in the study, each participant will respond to a questionnaire related to high altitude exposure (prior 3 months), as well as inclusion/exclusion criteria evaluation. On day 0, after the interview and signed informed consent, the participant will undergo a medical examination that will include a general objective examination. Participants will participate in a training on the emergency and safety procedures of the hypobaric hypoxia facility, as well as a refresh on cardiopulmonary resuscitation procedure. During the following two days (day 1 and 2) the study protocol will be executed (one test per day). The study protocol envisages: - a basal cognitive test battery - blind ascent in the hypobaric chamber to simulated altitude - cognitive test battery - 5 minutes of recorded chest compressions on dummies - cognitive test battery - blind descent in the hypobaric chamber. During the stay in the hypobaric hypoxic facility, each participant will be monitored in real time with the Equivital© medical monitoring device. Before and after the stay in the hypobaric hypoxic facility, a saliva sample will be collected, and psychological tests administered.