Variability in oxygen delivery with bag-valve-mask devices: An observational laboratory simulation study

Area of Science:

• Medical Devices
• Respiratory Care
• Patient Safety

Background:

• Bag-valve-mask (BVM) devices are crucial for manual ventilation and pre-oxygenation before intubation.
• Adequate pre-oxygenation requires an inspired oxygen fraction (FiO2) > 0.85.
• Variability in BVM design may impact oxygen delivery efficacy in spontaneously breathing patients.

Purpose of the Study:

• To evaluate the oxygen delivery efficacy of various adult and pediatric BVM devices.
• To assess the influence of BVM design on device performance during simulated spontaneous ventilation.
• To identify BVM devices that fail to meet adequate pre-oxygenation standards.

Main Methods:

• Forty BVM devices were tested using a mechanical lung simulating spontaneous breathing at various tidal volumes.
• Each device was supplied with 100% oxygen at 15 L/min for 2 minutes prior to testing.
• Inspired oxygen fraction (FiO2) was measured after 2 minutes of simulated spontaneous breathing.

Main Results:

• Eight of 40 devices failed to deliver FiO2 > 0.85 at least once; five models consistently failed.
• Three devices delivered FiO2 < 0.55.
• Poorest performing devices featured duckbill non-rebreather valves and lacked dedicated expiratory valves, with performance decreasing at higher tidal volumes.

Conclusions:

• Several BVM devices failed to provide adequate oxygen for pre-oxygenation in a simulated spontaneously breathing model.
• BVM design, particularly the presence of a duckbill non-rebreather valve and absence of a dedicated expiratory valve, significantly impacts performance.
• Clinicians must be aware of BVM limitations, and manufacturing standards should be updated to ensure reliable oxygen delivery.