Effect of Aerosol Devices and Administration Techniques on Drug Delivery in a Simulated Spontaneously Breathing Pediatric Tracheostomy Model

Respir Care. 2015 Jul;60(7):1026-32. doi: 10.4187/respcare.03592. Epub 2015 Mar 3.


Background: This study was conducted to compare the efficiency of jet nebulizers, vibrating mesh nebulizers, and pressurized metered-dose inhalers (pMDI) during assisted and unassisted administration techniques using a simulated spontaneously breathing pediatric model with a tracheostomy tube (TT).

Methods: An in vitro breathing model consisting of an uncuffed TT (4.5-mm inner diameter) was attached to a collecting filter (Respirgard) connected to a dual-chamber test lung and a ventilator (Hamilton Medical) to simulate breathing parameters of a 2-y-old child (breathing frequency, 25 breaths/min; tidal volume, 150 mL; inspiratory time, 0.8 s; peak inspiratory flow, 20 L/min). Albuterol sulfate was administered using a jet nebulizer (MicroMist, 2.5 mg/3 mL), vibrating mesh nebulizer (Aeroneb Solo, 2.5 mg/3 mL), and pMDI (ProAir HFA, 432 μg). Each device was tested 5 times with an unassisted technique (direct administration of aerosols with simulated spontaneous breathing) and with an assisted technique (using a manual resuscitation bag in conjunction with an aerosol device and synchronized with inspiration). Drug collected on the filter was analyzed by spectrophotometry.

Results: With the unassisted technique, the pMDI had the highest inhaled mass percent (IM%, 47.15 ± 7.82%), followed by the vibrating mesh nebulizer (19.77 ± 2.99%) and the jet nebulizer (5.88 ± 0.77%, P = .002). IM was greater with the vibrating mesh nebulizer (0.49 ± .07 mg) than with the pMDI (0.20 ± 0.03 mg) and the jet nebulizer (0.15 ± 0.01 mg, P = .007). The trend of lower deposition with the assisted versus unassisted technique was not significant for the jet nebulizer (P = .46), vibrating mesh nebulizer (P = .19), and pMDI (P = .64).

Conclusions: In this in vitro pediatric breathing model with a TT, the pMDI delivered the highest IM%, whereas the vibrating mesh nebulizer delivered the highest IM. The jet nebulizer was the least efficient device. Delivery efficiency was similar with unassisted and assisted administration techniques.

Keywords: aerosols; albuterol; drug delivery; metered dose inhaler; nebulizers; pediatrics; tracheostomy.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Administration, Inhalation
  • Aerosols / administration & dosage*
  • Albuterol / administration & dosage
  • Bronchodilator Agents / administration & dosage
  • Child, Preschool
  • Drug Delivery Systems / instrumentation*
  • Drug Delivery Systems / methods*
  • Equipment Design
  • Humans
  • Metered Dose Inhalers
  • Models, Theoretical
  • Nebulizers and Vaporizers
  • Pediatrics / instrumentation
  • Respiration*
  • Tidal Volume
  • Tracheostomy*


  • Aerosols
  • Bronchodilator Agents
  • Albuterol