Aerosol Delivery With and Without the Use of Different Mitigation Devices During Nebulization Treatments

Background: During nebulization via aerosol face mask, our previous in vivo study found fugitive aerosol concentrations could be reduced by using a face tent scavenger or a filter face mask. However, concerns were raised regarding the influence of these mitigations on aerosol delivery. This in vitro study was aimed to evaluate aerosol delivery efficiency with the use of scavenger and filter face mask during nebulization treatments. Methods: An adult manikin connected to a dual-chamber model lung, driven by a ventilator to simulate spontaneous breathing of VT of 470 mL, RR 21 breaths/min, and Ti of 1.2 s, with a collecting filter placed between the manikin’s trachea and the model lung. Albuterol (2.5mg in 3 mL) was administered via vibrating mesh nebulizer (VMN) and small volume jet nebulizer (SVN) with an aerosol face mask (n = 5). A face tent scavenger connected to negative pressure (-100 mm Hg), filter face mask, and standard face mask were compared, with tight and loose connection (fit to model) compared with VMN. After each run, the collecting filter was removed, with drug eluted and assayed with UV spectrophotometry (276 nm) Results: Inhaled dose was similar with and without scavenger, regardless of the nebulizer type (Table 1). The inhaled dose was also similar with standard and filter aerosol face mask for both VMN and SVN (Table 2). In contrast, a loose connection (fit) of the face mask significantly reduced inhaled dose, regardless of mask type (all P < .05). Conclusions: Mitigation devices (scavengers and filter masks) did not affect aerosol delivery during nebulization treatments. Facemask needs to be tightly connected to the subject’s face.Comparisons of aerosol delivery of nebulization via an aerosol facemask with vs without scavengerNebulizerInhaled dose (%)pWith scavengerWithout scavengerVibrating mesh nebulizer15.1 ± 1.115.5 ± 1.11.0Small volume jet nebulizer9.0 ± 0.78.7 ± 1.80.465Comparisons of aerosol delivery with different nebulizers via filter mask vs aerosol facemaskNebulizerTight connection with facemaskInhaled dose (%)pFilter facemaskAerosol facemaskSmall volume jet nebulizerYes9.8 ± 1.08.7 ± 1.80.465Vibrating mesh nebulizerYes17.1 ± 1.515.5 ± 1.10.175Vibrating mesh nebulizerNo11.8 ± 1.912.7 ± 1.1 P#0.0090.016 # comparison of inhaled dose between tightly vs loosely connected facemask