FiO2 is the fraction of inspired oxygen. Given that 100% oxygen is an FiO2 of 1.0, and room air (21%) has an FiO2 of 0.21, you can see the conversion is as simple as moving the decimal point 2 steps left. | ECT4Health- Nurse/Paramedic Education

Providing supplemental oxygen in the ICU often exposes patients to a high Fio2 and a higher-than-normal Pao2, which have been associated with increased mortality and fewer ventilator-free days. Studies have suggested that establishing regimens for limiting oxygen use could improve outcomes. New research findings are summarized in a short video. https://nej.md/2PZmFNA | The New England Journal of Medicine