Background: Selecting optimal aerosol device and interface of noninvasive ventilation (NIV) to children is a challenge. The purpose of this study is to measure the delivery efficiency of two nebulizers with three interfaces in a simulated spontaneously breathing pediatric lung model.

Methods: A ventilator (Trilogy 202, Philips) with single limb circuit (S/T mode, inspiratory pressure: 18 cmH₂O, expiratory pressure: 8 cmH₂O, respiratory rate: 30 and I:E ratio 1:2) was connected to a pediatric upper airway manikin via the standard oronasal mask (AF 541, Respironics), the oronasal mask with nose cushion (AF541, Respironics), and the nasal mask (PN 831 Respironics). A collecting filter was placed between the bronchi and a passive test lung (QuickLung, Ingmar Medical) with compliance of 20 mL/cmH₂O and resistance of 20 cmH₂O/L/s. Albuterol sulfate (2.5mg/3 ml) was administered with jet (Micro Mist, Hudson RCI, Temecula, CA) and mesh (Aerogen Solo, Aerogen Ltd, Galway, Ireland) nebulizers during noninvasive ventilation (n=5). Drug was eluted from filters and analyzed with spectrophotometry (276 nm). Descriptive statistics, Kruskal Wallis one way analysis of variance, and Mann Whitney U test were used for data analysis (p<0.05). Results: The result shows inhaled mass and inhaled dose % delivered (mean±SD) distal to the trachea. The mesh nebulizer delivered significantly greater drug deposition than the jet nebulizer with the standard oronasal mask (p=0.0001), the oronasal mask with nose cushion (p=0.0001), and nasal mask (p=0.047). Aerosol deposition with the standard oronasal mask was greater than the oronasal mask with nose cushion and the nasal mask using both jet and mesh nebulizers. Conclusion: Type of nebulizer and masks had an impact on aerosol drug delivery to this simulated passive pediatric lung model receiving noninvasive ventilation. Both oronasal masks were more efficient than the nasal mask by 15 – 20 fold, with either type of nebulizer. The Mesh delivered 2-3 folder more drug distal to the tracheal than the Jet Nebulizer.