What does FiO2 represent?

What does FiO2 represent?

• A. The fraction of inspired oxygen in the gas mixture delivered to the patient.
• B. The percentage of arterial oxygen in the blood
• C. The rate of oxygen flow to the patient
• D. The amount of oxygen dissolved in plasma

Answer: (A)

FiO2 is the fraction of inspired oxygen—the proportion of oxygen in the gas the patient is breathing. It’s usually expressed as a decimal or a percent (for example, room air is 0.21 or 21%). This value describes the gas mixture itself, not how much oxygen is in the blood, not the rate of oxygen flow, and not the amount dissolved in plasma. So it’s different from arterial oxygen percentage (PaO2 or SaO2), from flow rate, and from dissolved oxygen content in plasma. In practice, you adjust FiO2 on delivery devices or ventilators to meet the patient’s oxygenation needs, recognizing that the actual delivered FiO2 can be influenced by the device and breathing pattern.

FiO2 is the fraction of inspired oxygen—the proportion of oxygen in the gas the patient is breathing. It’s usually expressed as a decimal or a percent (for example, room air is 0.21 or 21%). This value describes the gas mixture itself, not how much oxygen is in the blood, not the rate of oxygen flow, and not the amount dissolved in plasma. So it’s different from arterial oxygen percentage (PaO2 or SaO2), from flow rate, and from dissolved oxygen content in plasma. In practice, you adjust FiO2 on delivery devices or ventilators to meet the patient’s oxygenation needs, recognizing that the actual delivered FiO2 can be influenced by the device and breathing pattern.