Question

Venturi mask delivers oxygen and flow?

• A. 50-70%, flow 10-15 L/min
• B. 21-40% FiO2, flow 2-4 L/min
• C. 24-50% FIO2, flow is 2-15 L/min
• D. 60-90% FiO2, flow is 15-20 L/min

Hint:

Oxygen delivery devices:
$\bullet$ Nasal Cannula: $24\text{--}44\%$ ($1\text{--}6\text{ L/min}$)
$\bullet$ Simple Face Mask: $35\text{--}55\%$ ($5\text{--}10\text{ L/min}$)
$\bullet$ Venturi Mask: $24\text{--}50\%$ ($2\text{--}15\text{ L/min}$, high-flow, fixed $\text{FiO}_2$)
$\bullet$ Non-Rebreather Mask: $60\text{--}90\%$ ($10\text{--}15\text{ L/min}$)

Answer 1

The Correct Option is C

Concept:
The Venturi (air-entrainment) mask is a high-flow oxygen delivery device designed to deliver a precise, fixed, and predictable fraction of inspired oxygen ($\text{FiO}_2$) regardless of the patient's respiratory rate or tidal volume.
It operates based on the Bernoulli principle and jet mixing, entraining room air through calibrated side ports.
Explanation:
• Venturi masks use color-coded interchangeable adapters or adjustable barrel valves that entrain specific proportions of ambient room air with pure oxygen.

• The system delivers a precise $\text{FiO}_2$ ranging from $24\%$ to $50\%$ (or up to $60\%$), utilizing oxygen flow rates between $2$ and $15\text{ L/min$}.

• Standard color codes and settings include:
- Blue: $24\%\text{ }\text{FiO}_2$ at $2\text{--}4\text{ L/min}$
- White: $28\%\text{ }\text{FiO}_2$ at $4\text{--}6\text{ L/min}$
- Yellow Orange: $31\%\text{--}35\%\text{ }\text{FiO}_2$ at $6\text{--}8\text{ L/min}$
- Red Green: $40\%\text{--}50\%\text{ }\text{FiO}_2$ at $8\text{--}15\text{ L/min}$

• Because the total flow delivered (oxygen plus entrained air) exceeds the patient's peak inspiratory flow rate, the delivered $\text{FiO}_2$ remains constant and accurate, making it ideal for patients with chronic hypercapnic respiratory failure.
Final Answer:
The Venturi mask delivers a controlled $\text{FiO}_2$ of $24\%\text{--}50\%$ at flow rates of $2\text{--}15\text{ L/min}$.