The gas mask is a device used in places where airborne pollutants and toxic gases are suspended in free air. The military grade gas mask goal is to prevent the user from inhaling said pollutants. Tracheotomy is frequently indicated for patients with COVID-19 suffering from severe acute respiratory syndrome.
The French Army Biomedical Research Centre provided our hospital with military masks equipped with P3 filter cartridges and an integrated ventilation unit that would allow the safe performance of this procedure when faced with a high risk of virus transmission.
FFP2 or FFP3 masks can provide proper protection, as these masks have an efficiency of 95%–99% when tested with 0.30 µm particles. However, their efficacy for SARS-CoV-2 protection has not been explored, and the virus has a smaller caliber. An additional concern is the potential risk of progressive degradation and increasing porosity, which could explain the lower efficiency of FFP2 or FFP3 masks compared with powered air-purifying respirators.
By contrast, the gas mask, originally designed to protect soldiers against biological and chemical attacks, provides full protection. The filter in the device is comparable with an FFP3 filter and can be fully effective for hours without performance degradation. The filter and the powered air-purifying respirator are also positioned at the back of the surgeon, away from the patient’s airways and from virus projection during the trachea incision. Gas masks can be useful when FFP3 masks are lacking or when operating in restricted military situations. Gas masks are also reusable after decontamination.