Venturi mask has a high flow rate of O₂ supply to the patient?

Appeared in: NORCET 2 -2021 (Shift-2)

Explanation

A Venturi mask is a high-flow oxygen delivery device that provides a precise fraction of inspired oxygen (FiO2).
It operates on the Bernoulli principle, entraining a fixed proportion of room air to mix with a set oxygen flow, allowing for accurate FiO2 delivery.
The typical range of FiO2 that can be delivered by a Venturi mask is from 24% to 60%, using different color-coded diluter jets.
This precision is crucial for patients with conditions like COPD, who require carefully controlled oxygen levels to avoid suppressing their respiratory drive.

Option B: This range is too narrow. It omits the lower concentrations (24%, 28%, 31%, 35%) that are frequently used, especially for patients with COPD who need precise, low-level oxygen therapy.
Option C: Delivering an FiO2 of 12% is physiologically harmful as it is below the oxygen concentration of room air (21%) and would cause hypoxia. The lowest setting for a Venturi mask is 24%.
Option D: This high FiO2 range is achieved with reservoir masks, such as a partial rebreather or a non-rebreather mask, which can deliver up to 95% oxygen. A Venturi mask's maximum is typically 60%.

Clinical Relevance

Nursing practice connection: Use the key finding related to Oxygen delivery devices and FiO2 range of a Venturi mask to guide bedside assessment, documentation, and the next nursing action.
Using a Venturi mask is crucial for patients with COPD, as it delivers a precise FiO2, preventing over-oxygenation which can suppress the hypoxic respiratory drive.
Nurses must ensure the oxygen flowmeter is set to the correct liter flow specified on the color-coded diluter to achieve the desired FiO2. Using an incorrect flow rate results in an inaccurate FiO2 delivery.
It is also vital to ensure the air entrainment ports on the diluter are not blocked by bed linens or clothing, as this would lead to the delivery of an unsafe, higher concentration of oxygen.

How to Approach the Question

First, identify the core of the question: it asks for the oxygen concentration (FiO2) range of a specific device, the Venturi mask.
This is a factual recall question. Access your knowledge about different oxygen delivery systems.
Recall that Venturi masks are high-flow systems known for precision. They are not for the highest possible FiO2 but for accurate FiO2.
Evaluate the options. Eliminate any range that is physiologically impossible (e.g., below 21% oxygen). Eliminate ranges associated with other devices (e.g., very high FiO2 for non-rebreather masks).
Select the option that represents the full, standard operating range of a Venturi mask, which typically starts at 24% and goes up to 50% or 60%.

Concept Tested & Keywords

QSVJjnYVjS2b56_ngmeLtI

E6 Nursing Fundamentals Taylor p. 731-733

E6 Nelson Textbook of Pediatrics(2024) — Volume 1 p. 663-665

Practise the full NORCET 2 -2021 (Shift-2)

Attempt every question from this paper in a timed mock, then review the full solution for each one.