Performance of the Hudson Multi-Vent oxygen mask

Area of Science:

• Respiratory therapy
• Biomedical engineering
• Medical device performance evaluation

Background:

• Oxygen masks are crucial for delivering supplemental oxygen to patients.
• Accurate oxygen delivery is vital for effective respiratory support.
• The Hudson Multi-Vent mask is a commonly used device, but its performance characteristics require thorough evaluation.

Purpose of the Study:

• To assess the performance of the Hudson Multi-Vent oxygen mask under varying conditions.
• To determine the accuracy of delivered oxygen concentrations at different inspiratory flow rates and mask orientations.
• To validate a head model for simulating oxygen mask performance in clinical settings.

Main Methods:

• A head model with oral and nasal orifices was used to simulate patient breathing.
• Varying inspiratory flow rates (20-100 L/min) were generated.
• Oxygen concentrations were measured at different mask positions and angles.
• In vivo measurements were taken from 12 hospital inpatients to validate model findings.

Main Results:

• Delivered oxygen concentration decreased significantly as inspiratory flow rate increased, with up to 50% loss of inspired oxygen.
• Mask orientation critically affected oxygen delivery; angling away from the face reduced concentration by over 50%.
• In vivo measurements in patients confirmed the model's accuracy, showing unpredictable oxygen delivery.
• Air entrainment occurred through side ports, diluting the oxygen concentration.

Conclusions:

• The Hudson Multi-Vent oxygen mask does not reliably deliver the set oxygen concentration.
• Delivered oxygen concentration is highly variable and unpredictable in clinical practice.
• Clinicians should be aware of these limitations when using this oxygen mask for respiratory support.