Impact of inspiration flow resistance of nebulizer on spontaneous breathing pattern and its effect on regional lung deposition

presentation, poster

en

Usually, the inspiration flow resistance is discussed in the context of dry powder inhalers. However, can it be important also in the case of nebulizers? The nebulizers are commonly used with spontaneous breathing. There are no studies dealing with the differences in spontaneous breathing caused by the pressure drop of nebulizers. Within this study, we measured the spontaneous breathing of 10 male subjects while they used a nebulizer Pari LC Sprint Star and during the breathing without any nebulizer. The breath recordings were performed by a spirometer SpiroSonic SMART. The flow rate vs. time breathing profiles were recorded. The time scale was normalized in each breathing cycle. The flow rate in each normalized time step was averaged through the recorded cycles and subsequently through the subjects. A significant difference was detected between the breathing profile with and without nebulizer. In the case of the nebulizer usage, the peak inspiration flow rate was significantly lower, and the average inspiration time was significantly longer than in the case without the nebulizer: PIFRPari_LC_Sprint_Star = 20.09 ± 8.54 l/min and PIFRNo_nebulizer = 40.23 ± 16.99 l/min; Ti_Pari_LC_Sprint_Star = 2.87 ± 0.76 s and Ti_No_inhaler = 1.83 ± 0.25 s. These breathing profiles were set as a boundary condition in the computational fluid dynamic simulations of aerosol deposition. The Reynolds averaged Navier-Stokes approach was used. The aerosol particle movement was solved by the Lagrangian approach and 4 different particle sizes were injected into the domain: 10 µm, 5 µm, 2.5 µm, and 1 µm. As a result of the nebulizer resistance the upper airway deposition decreased. According to these results, the drug delivery to the lungs is even more effective after considering the realistic breathing profile influenced by nebulizer resistance. This can be valuable information for further nebulizer drug delivery modeling

Usually, the inspiration flow resistance is discussed in the context of dry powder inhalers. However, can it be important also in the case of nebulizers? The nebulizers are commonly used with spontaneous breathing. There are no studies dealing with the differences in spontaneous breathing caused by the pressure drop of nebulizers. Within this study, we measured the spontaneous breathing of 10 male subjects while they used a nebulizer Pari LC Sprint Star and during the breathing without any nebulizer. The breath recordings were performed by a spirometer SpiroSonic SMART. The flow rate vs. time breathing profiles were recorded. The time scale was normalized in each breathing cycle. The flow rate in each normalized time step was averaged through the recorded cycles and subsequently through the subjects. A significant difference was detected between the breathing profile with and without nebulizer. In the case of the nebulizer usage, the peak inspiration flow rate was significantly lower, and the average inspiration time was significantly longer than in the case without the nebulizer: PIFRPari_LC_Sprint_Star = 20.09 ± 8.54 l/min and PIFRNo_nebulizer = 40.23 ± 16.99 l/min; Ti_Pari_LC_Sprint_Star = 2.87 ± 0.76 s and Ti_No_inhaler = 1.83 ± 0.25 s. These breathing profiles were set as a boundary condition in the computational fluid dynamic simulations of aerosol deposition. The Reynolds averaged Navier-Stokes approach was used. The aerosol particle movement was solved by the Lagrangian approach and 4 different particle sizes were injected into the domain: 10 µm, 5 µm, 2.5 µm, and 1 µm. As a result of the nebulizer resistance the upper airway deposition decreased. According to these results, the drug delivery to the lungs is even more effective after considering the realistic breathing profile influenced by nebulizer resistance. This can be valuable information for further nebulizer drug delivery modeling

Inspiration, nebulizer, breathing profile, airway, deposition.

24.11.2023

Chiesi Farmaceutici S.p.A.

Parma, Italy