FiO2 can be increased by increasing ____________ and/or altering O2 delivery device.

FiO2 can be increased by increasing ____________ and/or altering O2 delivery device.

• A. O2 purity
• B. Atmospheric pressure
• C. Flow rate
• D. Mask size

Answer: (C)

FiO2 is the fraction of inspired oxygen, determined by how much oxygen-rich gas is delivered to the patient with each breath. Increasing the flow rate of oxygen provides more oxygen per breath and reduces the amount of room air that can mix in during inhalation, so the inspired oxygen percentage rises. The delivery device also matters, because some devices trap and deliver more of the oxygen-rich gas (or limit air entrainment) than others, but the primary, actionable way to raise FiO2 in practice is to increase the flow rate. Oxygen purity is typically fixed in clinical settings (medical oxygen is already at near-pure O2), atmospheric pressure isn’t adjusted in routine care, and mask size mainly affects fit and comfort rather than reliably changing FiO2. Switching to a different device (like a reservoir or non-rebreather mask) can enable higher FiO2, but without increasing flow, the benefit is limited; increasing flow is the most direct way to raise FiO2.

FiO2 is the fraction of inspired oxygen, determined by how much oxygen-rich gas is delivered to the patient with each breath. Increasing the flow rate of oxygen provides more oxygen per breath and reduces the amount of room air that can mix in during inhalation, so the inspired oxygen percentage rises. The delivery device also matters, because some devices trap and deliver more of the oxygen-rich gas (or limit air entrainment) than others, but the primary, actionable way to raise FiO2 in practice is to increase the flow rate.

Oxygen purity is typically fixed in clinical settings (medical oxygen is already at near-pure O2), atmospheric pressure isn’t adjusted in routine care, and mask size mainly affects fit and comfort rather than reliably changing FiO2. Switching to a different device (like a reservoir or non-rebreather mask) can enable higher FiO2, but without increasing flow, the benefit is limited; increasing flow is the most direct way to raise FiO2.