Mode of Breathing—Tidal or Slow and Deep—through the I-neb Adaptive Aerosol Delivery (AAD) System Affects Lung Deposition of^99mTc-DTPA

Abstract

Background: The I-neb AAD System was designed to deliver aerosol with two different breathing pattern algorithms: the Tidal Breathing Mode (TBM) and the Target Inhalation Mode (TIM). For the purpose of the study, the TBM breathing pattern algorithm was set to guide the subjects to inhalation during tidal breathing with aerosol pulsed during 50-80% of the time spent on inhalation, whereas the TIM breathing pattern was set to guide the subject to a slow and deep inhalation of up to *9 sec with aerosol pulsed for up to 7 sec, leaving 2 sec for particle deposition in the lungs. In TIM, the inspiratory flow was guided to *20 L=min through a built-in resistance in the mouthpiece. Methods: We have, in a randomized, open-label, crossover study of 12 healthy subjects evaluated lung deposition following administration of a radiolabeled aerosol from the I-neb AAD System with the TBM and TIM breathing patterns. Results:The results showed that mean lung deposition was significantly higher when using the I-neb AAD System with the TIM breathing pattern (73.3%) than with the TBM breathing pattern (62.8%). The mean exhaled fractions were low (<1%) for both breathing patterns. The nebulization time was significantly shorter with the TIM breathing pattern (3.0 min) than with the TBM breathing pattern (4.7 min). Conclusions:The results of the present study showed that lung deposition with the slow and deep inhalation achieved through the I-neb AAD System in TIM was superior to the lung deposition achieved during tidal breathing in TBM. With the combination of high lung deposition, almost no loss of aerosol during exhalation, and short nebulization time the I-neb AAD System with the TIM breathing pattern should be of special value to patients who require multiple daily dosing of aerosolized medication, are using drugs that should not be wasted into the room air, or would benefit from a more efficient delivery system.

High-Efficiency Generation and Delivery of Aerosols Through Nasal Cannula During Noninvasive Ventilation

“…Furthermore, RH values below 60% indicate that additional evaporation is possible for changes in number concentration associated with cyclic changes in aerosol throughput. Maintaining high-efficiency delivery through the nasal passages during exhalation may require only generating the aerosol during inhalation, as with the study of Nikander et al (36) Deposition in the delivery lines of micrometer particles will depend on the configuration and curvature of the tubes. However, submicrometer particles will have very low depositional losses in the delivery tubes for practical radii of curvature.…”

Effect of Drug Targeting Nebulization on Lung Deposition: A Randomized Crossover Scintigraphic Comparison Between Central and Peripheral Delivery

“…28 Slow and deep inhalation (as in our protocol) helps to reduce the extrathoracic deposition in comparison with tidal inhalation. 30 The Akita was demonstrated to deliver ϳ70% of the nominal dose to the lung independent of lung disease or severity, 28 which is much higher than the lung deposition obtained with all other forms of nebulization. However, in our study, this percentage was lower.…”

Inhaled antibiotics: dry or wet?

“…power. Lung deposition of mesh nebulisers is more efficient than conventional nebulisers, varying between 30% and 80% of the loading dose, depending on the device [42].…”

“…Smart nebulisers are substantially more efficient and may achieve lung deposition of 60-80% of the loading dose (using mesh technology) [42], compared with 5-15% with traditional jet nebulisers [43]. Furthermore, more efficient deposition of aerosol in the small airways can be achieved, which may result in more effective treatment of small airway obstruction [44].…”