The Effect of Different Interfaces on the Aerosol Delivery with Vibrating Mesh Nebulizer During Noninvasive Positive...

The effect of different interfaces on the aerosol delivery with vibrating mesh nebulizer during noninvasive positive pressure ventilation (NIV) is not clear. Noninvasive ventilator and four interfaces were connected to IngMar ASL 5000 lung simulator. Meanwhile, the vibrating mesh nebulizer was connected to a ventilator circuit to simulate the nebulization during noninvasive ventilation. The nebulizer position was placed at proximal position (near the mask) and distal position (15 cm away from the mask); the inspiratory positive airway pressure (IPAP) and the expiratory positive airway pressure (EPAP) were set to 16/4, 16/8, 20/4, and 20/8 cmH₂O, respectively. The aerosol was collected through a disposable filter placed between the simulated lung and the mask, after which the aerosol delivery was calculated. Meanwhile, we recorded the inspiratory tidal volume and the mean inspiratory flow. The aerosol delivery varied between 1.7% ± 0.0% and 21.1% ± 1.1%. Only when EPAP was set to 4 cmH₂O, the statistical difference in aerosol delivery was observed between the two types of interface, and between different leak port locations (p < 0.01; p = 0.04, respectively). When IPAP/EPAP was set to 16/4 and 20/4 cmH₂O, respectively, at different nebulizer positions, there was a statistical difference between the interface with the same type but different leak port locations and between the interface with same leak port location but different inner volumes (all p < 0.01). Also, there was a correlation between the aerosol delivery and interface volume (p < 0.01, R² = 0.55; p < 0.01, R² = 0.51, respectively), and between aerosol delivery and the intentional leak of interfaces (p < 0.01, R² = 0.59; p < 0.01, R² = 0.48, respectively). When EPAP was set to 4 and 8 cmH₂O, respectively, the aerosol delivery of nebulizer distal position was significantly higher than that of proximal position (12.2% ± 5.0% vs. 9.1% ± 4.1%, p < 0.05; 2.5% ± 0. 5% vs. 2.1% ± 0.3%, p < 0.01, respectively). Interfaces have a significant effect on aerosol delivery during NIV. The interfaces with different inner volumes, intentional leak, and leak port location may all have an effect on aerosol delivery. The addition of a 15 cm tube between the nebulizer and the mask significantly increases the aerosol delivery.