What is the advantage of venturi mask?

DSSSB - 28 August 2019 (Shift-1)

Edition 3

Easy

Appeared in: DSSSB - 28 August 2019 (Shift-1)

Explanation

The main advantage of a Venturi mask is its ability to deliver a precise, fixed, and known concentration of oxygen.
It functions as a high-flow device because the total flow (oxygen + entrained air) meets the patient's inspiratory demand, ensuring the delivered FiO₂ is not diluted by breathing in extra room air.
This precision is achieved through color-coded entrainment devices (diluters) that mix a specific volume of room air with a set oxygen flow rate.
This feature is especially crucial for patients with COPD, where precise, lower-level oxygenation is needed to prevent suppression of the hypoxic respiratory drive.

Option A: While the delivery is accurate, a Venturi mask does not deliver a 'high concentration' of oxygen compared to other devices. A non-rebreather mask, for example, can deliver up to 95% FiO₂, whereas a Venturi mask typically goes up to 50%. The key advantage is precision, not high concentration.
Option B: This describes the use of a simple face mask, which is often used for short periods when an increased, but not necessarily precise, amount of oxygen is needed.
Option C: This is the function of a nebulizer or an aerosol mask, not a Venturi mask. These devices are designed to deliver medication or humidity in the form of an aerosolized mist.

Clinical Relevance

Nursing practice connection: This is primarily an exam-oriented knowledge point with limited direct bedside application, so retain Oxygen Delivery Devices: Venturi Mask as background academic context rather than a clinical decision trigger.
A nurse's primary responsibility when managing a patient with a Venturi mask is to ensure the correct color-coded diluter is used as prescribed and that the oxygen flowmeter is set to the rate specified for that diluter.
It is crucial to check that the air entrainment ports on the diluter are not blocked by the patient's bedding or clothing, as this would obstruct air mixing and lead to the delivery of an inaccurate (and dangerously high) oxygen concentration.
What if? If a COPD patient on a 28% Venturi mask becomes more short of breath and their SpO₂ drops, the nurse should not independently increase the oxygen concentration. The first step is to perform a full respiratory assessment, check that the equipment is functioning correctly (no blockages), and then notify the physician. An indiscriminate increase in FiO₂ could suppress their respiratory drive.

How to Approach the Question

First, identify the core subject of the question: the 'advantage' of a 'Venturi mask'.
Recall the primary principle of the Venturi mask. Its unique feature is not the amount of oxygen it can deliver, but the precision with which it delivers it.
Evaluate the options based on this principle. Look for keywords like 'precise,' 'accurate,' or 'fixed concentration.'
Option A mentions 'accurately' but pairs it with 'high concentration,' which is not always the case. Option D includes 'precise' and 'high flow rates' (referring to the total gas flow), which is the most complete and accurate description of its function.
Eliminate options that describe other devices. Option C describes a nebulizer, and Option B is more characteristic of a simple mask.
Conclude that the most distinct and important advantage is the ability to deliver a precise oxygen concentration, making Option D the best answer.

Concept Tested & Keywords

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E6 Nursing Fundamentals Taylor p. 731-733