Table 2. Summary of recent studies that compared low versus high oxygenation targets in stroke and myocardial infarction.

mRS, modified Rankin Scale; NBO, normobaric oxygen; RCT, randomized controlled trial.

Study	Design	Sample Size	Etiology	Intervention	Main Findings
Hofmann et al. [42]	RCT	6,629	Myocardial infarction	6 L/min (6–12 h) open-face mask or ambient air.	The median oxygen saturation was 99% in oxygen therapy compared to 97% in ambient air. The death outcome in both groups was insignificant, with 5.0% observed in the oxygenated group and 5.1% in ambient air patients.
Khoshnood et al. [43]	RCT	100	Myocardial infarction	Supplemental oxygen (10 L/min) or room air.	No difference was observed in infarct size.
Ali et al. [38]	RCT	289	Stroke	Treatment group: oxygenation at 2–3 L/min for 72 h; Control: room temperature.	At the end of 6 mo., the mortality rate was comparable between the two groups, with 22 (15%) and 20 (14%) patients dying in the oxygen and control groups, respectively.
Mazdeh et al. [39]	RCT	52	Stroke	Oxygen saturation 50%.	No significant difference was found in the constitutions of ischemic-hemorrhagic strokes between the two groups (P=0.200). No difference was observed in mRS (P=0.800).
Ranchord et al. [44]	RCT	136	Myocardial infarction	Oxygen saturation 93–96%.	The mortality rate doubled in the oxygen saturation group compared to the high concentration group. No significant difference in troponin T levels was observed between high-concentration oxygen and titrated oxygen.
Roffe et al. [40]	RCT	8,003	Acute stroke	Oxygenation via nasal tube (3 L/min). Oxygen saturation ≤93%. Rate = 2 L/min when oxygen saturation ≥93%.	Improved outcomes were observed in the higher oxygenation group.
Shi et al. [41]	Animal model	128	Stroke	100% oxygen (NBO) or normoxia 21% oxygen.	NBO showed a reduction in blood occluding levels with improved neurological outcomes.