Influence of Aerosol Mask Design on Fugitive Aerosol Concentrations During Nebulization

BACKGROUND:
Secondhand exposure to fugitive aerosols may cause airway diseases in health providers. We hypothesized that redesigning aerosol masks to be closed-featured would reduce the fugitive aerosol concentrations during nebulization. This study aimed to evaluate the influence of a mask designed for a jet nebulizer on the concentration of fugitive aerosols and delivered doses.


METHODS:
An adult intubation manikin was attached to a lung simulator to mimic normal and distressed adult breathing patterns. The jet nebulizer delivered salbutamol as an aerosol tracer. The nebulizer was attached to 3 aerosol face masks: an aerosol mask, a modified non–rebreathing mask (NRM, with no vent holes), and an AerosoLess mask. An aerosol particle sizer measured aerosol concentrations at parallel distances of 0.8 m and 2.2 m and a frontal distance of 1.8 m from the manikin. The drug dose delivered distal to the manikin's airway was collected, eluted, and analyzed using a spectrophotometer at a 276 nm wavelength.


RESULTS:

With a normal breathing pattern, the trends of aerosol concentrations were higher with an NRM followed by an aerosol mask and AerosoLess mask (
P
< .001) at 0.8 m; however, the concentrations were higher with an aerosol mask followed by NRM and AerosoLess mask at 1.8 m (
P
< .001) and 2.2 m (
P
< .001). With a distressed breathing pattern, the aerosol concentrations were higher with an aerosol mask followed by an NRM and AerosoLess mask at 0.8 m, 1.8 m (
P
< .001), and 2.2 m (
P
= .005). The delivered drug dose was significantly higher with AerosoLess mask with a normal breathing pattern and with an aerosol mask with a distressed breathing pattern.



CONCLUSIONS:
Mask design influences fugitive aerosol concentrations in the environment, and a filtered mask reduces the concentration of aerosols at 3 different distances and with 2 breathing patterns.