Venturi mask

A Venturi mask is a high-flow oxygen delivery device used in respiratory therapy. It is a type of fixed-performance device, meaning it delivers a precise and predictable concentration of oxygen to the patient, regardless of the patient's breathing pattern.

The mask utilizes the Venturi effect, a principle of fluid dynamics where the pressure of a fluid (in this case, oxygen and air) decreases as it passes through a constricted area. By precisely controlling the size of the constriction and the oxygen flow rate, the mask entrains a specific amount of room air. This mixture of oxygen and air is then delivered to the patient.

Different colored adapters or adjustable valves on the mask control the proportion of oxygen and air, allowing for the delivery of various oxygen concentrations (FiO2), typically ranging from 24% to 60%. The desired FiO2 is selected based on the patient's clinical condition and arterial blood gas results.

Venturi masks are commonly used in patients with chronic obstructive pulmonary disease (COPD) or other conditions where precise oxygen delivery is crucial to avoid complications like carbon dioxide retention. The predictability of the oxygen concentration makes it a valuable tool for managing hypoxemia in these patient populations. The high flow rate also helps to wash out exhaled carbon dioxide from the mask, reducing the risk of rebreathing.

Unlike nasal cannulas or simple face masks, the Venturi mask is less dependent on the patient's respiratory rate and tidal volume for consistent oxygen delivery. This makes it particularly useful for patients with irregular breathing patterns. However, proper fitting and adherence to the prescribed oxygen flow rate are essential to ensure accurate oxygen delivery. The mask must be snugly fitted to the patient's face to prevent leakage of room air, which would dilute the delivered oxygen concentration. Regular monitoring of the patient's oxygen saturation and clinical status is also necessary.