Comparison of aerosol delivery across combinations of drug delivery interfaces with and without concurrent high-flow nasal therapy

Abstract

Background Current clinical practice during high-flow nasal therapy (HFNT) involves utilization of a nasal cannula to provide humidification, with a facemask placed over the cannula to deliver aerosol. Few studies have compared aerosol delivery across various delivery interfaces during HFNT. The objective of this study was to address this gap in the literature and evaluate aerosol delivery using two nebulizer types across different drug delivery interfaces, nasal cannula, facemask, and mouthpiece, during simulated adult HFNT. Methods A facemask or mouthpiece and/or a nasal cannula were positioned on an anatomically correct adult head model. The head model was connected to a breathing simulator via a collection filter. Both healthy breathing pattern and distressed breathing patterns were utilized. Aerosol dose was determined by quantifying the mass of drug captured on a filter positioned distal to the trachea. Results During simulated healthy breathing, a significantly greater aerosol dose was observed when the vibrating mesh nebulizer (VMN) was integrated with HFNT alone, supplying aerosol and humidified air simultaneously (2.88 ± 0.15%), as opposed to using with a facemask (0.33 ± 0.07%, 1.62 ± 0.46%, and 1.07 ± 0.25% at 0 L/min (LPM), 2LPM, and 6LPM, respectively) or mouthpiece (0.56 ± 0.13%, 2.16 ± 0.06%, and 1.82 ± 0.41% at 0LPM, 2LPM, and 6LPM). In addition, aerosol delivery was also significantly greater when the VMN was integrated into simulated HFNT (2.88 ± 0.15%), in comparison with using the jet nebulizer (JN) with a facemask (0.82 ± 0.16%) or a mouthpiece (0.86 ± 0.11%). During simulated distressed breathing, a significantly greater aerosol dose was observed when the VMN was integrated with HFNT, supplying aerosol and humidified air simultaneously (6.81 ± 0.45%), compared with using a facemask (0.86 ± 0.04%, 2.96 ± 0.26%, and 4.23 ± 0.93% at 0LPM, 2LPM, and 6LPM) or mouthpiece (0.73 ± 0.37%, 0.97 ± 0.20%, and 3.11 ± 0.53% at 0LPM, 2LPM, and 6LPM, respectively). Aerosol delivery was also greater when the VMN was integrated into HFNT (6.81 ± 0.45%), in comparison with using the JN with a facemask (5.72 ± 0.71%) or a mouthpiece (0.69 ± 0.53%). Furthermore, across all drug delivery interfaces, and in line with previous reports, aerosol delivery was greater during simulated distressed breathing, in comparison with simulated healthy adult breathing. Conclusions This article will be of considerable benefit in enhancing the understanding of aerosol delivery during HFNT, an increasingly adopted therapeutic intervention by healthcare professionals.

In vitro comparison of unit dose vs infusion pump administration of albuterol via high‐flow nasal cannula in toddlers

“…Inhaled dose via mask with VMN was similar at both 2 and 8 L/min, consistent with Bennett et al's finding using adult manikin. The inhaled dose with VMN mask trended higher than SVN with mask, which is likely due to the lower residual drug remaining at end of dose with VMN (<0.1 mL) than SVN (0.5‐1.0 mL) …”

“…Similar to other in vitro studies, the manikin did not simulate microstructures or complexity of human airways and use of collecting filters that do not represent aerosol exhaled in vivo, tend to overestimate inhaled dose. However, the proportional changes of inhaled dose between parameters tested should be representative.…”

“…29 The inhaled dose with VMN mask trended higher than SVN with mask, which is likely due to the lower residual drug remaining at end of dose with VMN (<0.1 mL) than SVN (0.5-1.0 mL). 30…”

Year in Review 2019: High-Flow Nasal Cannula Oxygen Therapy for Adult Subjects

“…Placing a face mask with nebulizer over the HFNC may result in the substantial reduction of the intended inhaled dose. 63 As such, placing a nebulizer in-line with HFNC has become a delivery route of interest. 64,65 Concerns have been raised about the inhaled dose via the trans-nasal aerosol delivery method.…”

Defining a Regulatory Strategy for ATMP/Aerosol Delivery Device Combinations in the Treatment of Respiratory Disease

“…In the case of simple bronchodilators, appropriate targeting through the selection of aerosol droplet sizes has been shown to significantly enhance inhaled drug therapy [ 90 ]. Patient-related factors such as breath pattern, position, and disease condition are also known to influence aerosol deposition and distribution [ 88 , 91 , 92 , 93 ].…”