Which oxygen delivery device provides fixed, precise oxygen concentration using a venturi mechanism and can be used with a mask or a tracheostomy?

Which oxygen delivery device provides fixed, precise oxygen concentration using a venturi mechanism and can be used with a mask or a tracheostomy?

• A. Air entrainment (venturi) mask
• B. Simple face mask
• C. Nasal cannula
• D. Non-rebreather mask

Answer: (A)

The main idea is delivering a known, fixed oxygen concentration using a venturi (air-entrainment) mechanism. In this setup, oxygen is forced through a narrow jet and, through fixed entrainment ports, a precise amount of room air is drawn in. The result is a calibrated mixture with a specific FiO2 that stays relatively constant despite changes in the patient’s breathing effort or tidal volume. Different adapters or color-coded slots set that concentration, typically within a range like around 24% to 50% (and sometimes higher with certain configurations). Because the FiO2 is determined by the device's design, not by how hard the patient breathes, it’s particularly useful when you need a reliable, predictable oxygen level. The mask or tracheostomy adapter simply provides a path for delivering that pre-set mixture to the patient. This is why it’s the best choice: other common devices don’t give a fixed FiO2. A simple face mask and a nasal cannula deliver variable oxygen concentrations that depend on how the patient breathes and how well the mask fits. A non-rebreather can deliver high oxygen content, but the exact FiO2 can still fluctuate based on flow rates and leaks, and it doesn’t rely on the venturi principle to enforce a precise concentration.

The main idea is delivering a known, fixed oxygen concentration using a venturi (air-entrainment) mechanism. In this setup, oxygen is forced through a narrow jet and, through fixed entrainment ports, a precise amount of room air is drawn in. The result is a calibrated mixture with a specific FiO2 that stays relatively constant despite changes in the patient’s breathing effort or tidal volume. Different adapters or color-coded slots set that concentration, typically within a range like around 24% to 50% (and sometimes higher with certain configurations). Because the FiO2 is determined by the device's design, not by how hard the patient breathes, it’s particularly useful when you need a reliable, predictable oxygen level. The mask or tracheostomy adapter simply provides a path for delivering that pre-set mixture to the patient.

This is why it’s the best choice: other common devices don’t give a fixed FiO2. A simple face mask and a nasal cannula deliver variable oxygen concentrations that depend on how the patient breathes and how well the mask fits. A non-rebreather can deliver high oxygen content, but the exact FiO2 can still fluctuate based on flow rates and leaks, and it doesn’t rely on the venturi principle to enforce a precise concentration.