## **Core Concept**
The Venturi mask, also known as a Venti mask, is a medical device used to deliver a specific, high concentration of oxygen to patients. It operates based on the principle of jet mixing, where oxygen flow creates a specific oxygen concentration.

## **Why the Correct Answer is Right**
The Venturi mask can deliver oxygen concentrations ranging from approximately 24% to 60%, depending on the specific Venturi valve used. The maximum oxygen concentration that can be reliably delivered by a Venturi mask is around 60%. This is because different colored jets or valves are used to achieve specific oxygen concentrations (e.g., 24%, 28%, 31%, 35%, 40%, and 60%). The 60% concentration is typically the highest achievable and is used for patients requiring high concentrations of oxygen.

## **Why Each Wrong Option is Incorrect**
- **Option A:** This option is incorrect because it does not specify a concentration that matches the maximum achievable with a Venturi mask.
- **Option B:** This option might seem plausible but does not accurately reflect the maximum concentration achievable with a standard Venturi mask.
- **Option C:** While closer, this option still does not accurately represent the maximum oxygen concentration that can be delivered by a Venturi mask.

## **Clinical Pearl / High-Yield Fact**
A key point to remember is that Venturi masks are particularly useful for patients with chronic obstructive pulmonary disease (COPD) who may have a hypoxic drive to breathe. The precise control over oxygen concentration helps prevent suppression of this drive. Also, remember that the Venturi mask's effectiveness depends on the proper selection of the valve to achieve the desired oxygen concentration.

## **Correct Answer:** D. 60%.