FiO2 stands for Fraction of Inspired Oxygen; it is a fraction of the amount of oxygen a patient is inhaling produced by an oxygen device such as a nasal cannula or mask. Different devices deliver different amounts of oxygen to the patient.Continue Reading
With a nasal cannula, it is assumed that the patient's oxygen intake increases 4 percent for every liter of oxygen that flows through the cannula.
Using a Venturi mask, which mixes air from the room with the oxygen, provides an accurate and constant FiO2 unlike the nasal cannula. It is often used when doctors are worried about carbon dioxide retention.