Efficacy of Various Mitigation Devices in Reducing Fugitive Emissions from Nebulizers

Respir Care. 2022 Apr;67(4):394-403. doi: 10.4187/respcare.09546. Epub 2021 Nov 9.

Abstract

Background: Fugitive aerosol concentrations generated by different nebulizers and interfaces in vivo and mitigation of aerosol dispersion into the environment with various commercially available devices are not known.

Methods: Nine healthy volunteers were given 3 mL saline with a small-volume nebulizer (SVN) or vibrating mesh nebulizer (VMN) with a mouthpiece, a mouthpiece with an exhalation filter, an aerosol mask with open ports for SVN and a valved face mask for VMN, and a face mask with a scavenger (Exhalo) in random order. Five of the participants received treatments using a face tent scavenger (Vapotherm) and a mask with exhalation filter with SVN and VMN in a random order. Treatments were performed in an ICU room with 2 particle counters positioned 1 and 3 ft from participants measuring aerosol concentrations at sizes of 0.3-10.0 μm at baseline, before, during, and after each treatment.

Results: Fugitive aerosol concentrations were higher with SVN than VMN and higher with a face mask than a mouthpiece. Adding an exhalation filter to a mouthpiece reduced aerosol concentrations of 0.3-1.0 μm in size for VMN and 0.3-3.0 μm for SVN (all P < .05). An Exhalo scavenger over the mask reduced 0.5-3.0 μm sized particle concentrations for SVN (all P < .05) but not VMN. Vapotherm scavenger and filter face mask reduced fugitive aerosol concentrations regardless of the nebulizer type.

Conclusions: SVN produced higher fugitive aerosol concentrations than VMN, whereas face masks generated higher aerosol concentrations than mouthpieces. Adding an exhalation filter to the mouthpiece or a scavenger to the face mask reduced aerosol concentrations for both SVN and VMN. Vapotherm scavenger and filter face mask reduced fugitive aerosols as effectively as a mouthpiece with an exhalation filter. This study provides guidance for reducing fugitive aerosol emissions from nebulizers in clinical practice.

Keywords: aerosol generation procedure; aerosol transmission; fugitive aerosol; nebulization.

MeSH terms

  • Administration, Inhalation
  • Aerosols
  • Albuterol
  • Bronchodilator Agents*
  • Equipment Design
  • Humans
  • Masks
  • Nebulizers and Vaporizers*

Substances

  • Aerosols
  • Bronchodilator Agents
  • Albuterol