(337) Assessing Variability in Performance of Nebulizer- Compressor Systems for Patients with Cystic Fibrosis in Support of Hypothesis that Switching Nebulizers can Result in Inconsistent Dosing

Background: Nebulizer-portable compressors are widely prescribed delivering inhaled medications for homecare of cystic fibrosis patients. These components are often supplied together. However, a different nebulizer brand may be substituted where replacements are supplied separately, and such replacements can have inferior performance [1]. The purpose of this study was to quantify the range of an in vitro performance measures associated with effectiveness of medication delivery for targeting the airways of the lungs.

Methods: The following nebulizer-compressor systems were evaluated, delivering a 3-ml fill of aqueous albuterol solution (833 mg/mL) from the nebulizer mouthpiece to a filter coupled to a breathing simulator (ASL 5000), sampling mimicking adult use (tidal volume = 600 ml; inspiratory/expiratory ratio 1:2; rate = 10 cycles/min):



< !A. MC 300* reusable nebulizer/OMBRA* table-top compressor (MC300-R/O)

<BB. Sidestream* reusable/Sami the Seal* compressor (SS-R/S)

< !C. Sidestream* disposable Nebulizer with Innospire* Elegance*compressor (SS-D/E)

< !D. Sidestream* reusable Nebulizer with Willis the Whale* compressor (SS-R/W)

< !E. Sidestream* disposable Nebulizer with Willis the Whale* compressor (SS-D/W)

< !F. LC Sprint* reusable nebulizer/ with PRONEB* Max compressor (LC-Sprint-R/P)

< !G. LC Sprint* reusable nebulizer with PARI VIOS* compressor (LC-Sprint-R/V)

< !H. VixOne* disposable nebulizer with PARI VIOS* compressor (VixOne-D/V)



Total droplet mass (TM) was determined at each 1 min time step from start of nebulization to onset of sputter. Droplet size distributions (n = 5 replicates/system) were determined in parallel by laser diffraction (Malvern Spraytec, Malvern Panalytical, UK) from which fine droplet mass (FDM_{< 4.7 μm}) was determined as the product of TM and fine droplet fraction (FDF_{< 4.7 μm}).

Results: Times to sputter were in the range 7 to 9 min for all systems. Cumulative FDM_{< 4.7 μm} (mean ± SD) was linear vs. elapsed time for each system until sputtering (Figure 1). The rate of albuterol delivery in fine droplets varied widely from 1.3 ± 0.1 μg/s to 0.3 ± 0.0 μg/s for best and worst performing systems F and H respectively. The corresponding values of total FDM_{< 4.7 μm} were 429.0 ± 27.4 μg delivered in 7 min compared with 171.0 ± 6.2 μg delivered in 9 min. Notably, inter-device variability (relative SD. (%)) in FDM_{< 4.7 μm} for the reusable LC Sprint* nebulizer was almost 4-times as large when paired with the VIOS* compressor (system G, 22.7%) compared with system F (6.4%), in which the same nebulizer was paired with the PRONEB* compressor. Changing from the LC-Sprint* with the VIOS* compressor (system G) to the VixOne* device with the same compressor (system H) resulted in a 40% decrease in total FDM_{< 4.7 μm} from 283.7 ± 64.2 μg to 171.0 ± 6.2 μg.

Conclusions: Clinicians should be aware that each nebulizer-compressor combination has its unique medication delivery profile. Substituting one nebulizer for another even with the same compressor can result in large differences in lung delivery of medication to the patient.

Acknowledgements: The work was supported by funding from Monaghan Medical Corporation, Plattsburgh, USA.

References: [1] Lester M, Eidson D, Blair S. et al., Respir Care, 2021; 66(12): 1840-7.