Adjuvant Cerebroprotection Using Normobaric Hyperoxia in Pre-hospital Patients with Suspected Stroke

Prior treatment

• Endotracheal intubation in the field (prior to consent);
• Known history of severe chronic obstructive pulmonary disease (FEV1 less than 1.0), New York Heart Association (NYHA) Heart Failure Class III, acute pulmonary infection or aspiration pneumonia, prior to enrollment;
• Participating in another clinical trial, or completed participation within prior 30 days;
• Receiving other neuroprotective agent (e.g., edaravone dexborneol, n-butylphthalide);

Other illness

• Seizure at stroke onset;

Age

• Known pregnancy: women of childbearing age (18 to 44 years old according to the CDC's Division of Reproductive Health) will be asked about their pregnancy status.

Other

• Respiratory rate \<= 10 or \>= 30 breaths per minute;
• Oxygen-dependence at baseline to maintain SaO2 \> 95%;
• Exhibiting symptoms of vomiting, severe headache, or unconscious;
• Life expectancy \< 90 days due to comorbidities;
• Unlikely to complete the 90-day follow-up visit.

• Age 18 to 80 years old;
• Signs and symptoms are consistent with a new acute stroke, with low possibility of stroke mimics (e.g., no sudden coma, prior seizure disorder, suspected hypoglycemia);
• No prior stroke;
• The time from stroke onset/last seen well to randomization is within 6 hours;
• Paramedic-obtained FAST-ED score \>= 3 (The enrollment of patients with a FAST-ED score of 3 is prespecified to constitute no more than 10% of the total study population);
• No significant pre-stroke disability (pre-stroke mRS 0-1);
• Signed informed consent from the patient or the legally authorized representative (LAR).