The Role of Hyperoxia in Acute Ischemic Stroke

Inclusion Criteria: 1. Provision of signed and dated informed consent form from patient or legal authorized representative (LAR) 2. Subject or LAR stated willingness to comply with all study procedures and availability for the duration of the study 3. Males and females (of unlikely childbearing capacity) aged over 18 years. 4. Exhibiting signs and physical examination findings suggestive of an acute ischemic infarction (either a or b) 1. A target mismatch profile of CT-perfusion or MRI determined by RAPID automated software to have a ratio of PWITmax\>6 lesion volume/DWI lesion volume \>1.2 and an NIHSS \>/=1 2. A RAPID automated software calculated non-contrast CT-head ASPECT score of 10 and LKW ≤12 hours (in patients with symptoms discovered upon waking, the LKW is defined at the midpoint between going to sleep and awakening based on previous studies that suggest most strokes during sleep occur close to awakening) 5. Normoxic; a pulse oximetry of 94% or greater at time of screening without the use of supplemental oxygen Exclusion Criteria: 1. Current use of supplemental oxygen 2. Prisoner 3. Documented blood glucose \<70mg/dL 4. Concurrent treatment with another investigational drug or other intervention 5. Documented history of any of the following chronic respiratory illness that require pulmonary vasodilators or supplemental oxygen at baseline: Chronic Obstructive Pulmonary Disorder (COPD), Emphysema, Interstitial Lung Disease, Restrictive Lung Disease, Pulmonary Hypertension 6. Documented history of any of the following autoimmune diseases: systemic lupus erythematosus, rheumatoid arthritis, scleroderma, primary biliary cholangitis, multiple sclerosis, inflammatory bowel disease 7. Currently being treated for an acute myocardial infarction and/or decompensated heart failure at the onset of initial ED presentation as reported by the ED provider 8. Plans for treatment with either IV tPA (alteplase) or endovascular therapy