Effect of Nebulizer Type,Delivery Interface and Flow on Aerosol Drug Delivery to a Spontaneously Breathing Infant Lung Model

Abstract

Background:

Aerosol drug delivery to infants is affected by types of nebulizers, interface, and flows used during therapy. The purpose of this study is to determine the effect of nebulizer type, delivery interface and flow on aerosol drug delivery to a spontaneously breathing infant lung model.

Methods:

A teaching mannikin head was attached to a sinusoidal pump via a collecting filter at the bronchi to simulate a spontaneously breathing child (V_T: 100 mL, RR: 30 breaths/min and Ti: 0.7 s) Albuterol sulfate was nebulized with jet (Mistymax 10, Cardinal Health) and mesh (Aerogen Solo, Aerogen) nebulizers using low flow nasal cannula (LFNC, Hudson), high flow nasal cannula (HFNC, Fisher & Paykel), and face mask (FM, Hudson). Each device and interface were tested at appropriate flows as shown in the table below (n=3). Drug was eluted from the filter and analyzed by spectrophotometry. Descriptive statistics, Kruskal Wallis, Wilcoxon Sum rank, and Mann- Whitney U tests were used for data analysis. P<0.05 was considered statistically significant.

Results:

Table shows percent of nominal dose delivered distal to the trachea with each nebulizer and interface at various flows tested in this study. While no significant difference was found between jet and mesh nebulizers using LFNC (P=0.643), jet nebulizers were significantly less efficient than mesh nebulizers when they are combined with HFNC (P=0.012) and face mask (P=0.002) at 6 L/min. Delivery efficiency of face mask was significantly greater than LFNC and HFNC with jet (P=0.0001 and P=0.0001, respectively) and mesh nebulizers (P=0.001 and P=0.001, respectively) at 6 L/min. Drug delivery with LFNC at 2 L/min was significantly greater than 4 L/min and 6 L/min using mesh nebulizers (P=0.031 and P=0.015, respectively). There was no significant difference between 4 and 6 L/min using LFNC (P=0.790). Aerosol delivery with HFNC significantly decreased (P=0.007) when the flow increased from 6 L/min to 8 L/min with mesh nebulizers. Aerosol deposition obtained with the face mask at 6 L/min and 8 L/min were not statistically significant with jet (P=0.209) and mesh (P=0.452) nebulizers.

Conclusions:

Type of nebulizer, delivery interface and flow affect aerosol drug delivery to the spontaneously breathing infant lung model used in this study. Decreasing flow with LFNC, and HFNC increased aerosol deposition obtained with mesh nebulizers.

Interfaces	Low Flow Nasal Cannula (LFNC)			High Flow Nasal Cannula (HFNC)		Face Mask (FM)
Flow Rates	2 L/min	4 L/min	6 L/min	4 L/min	6 L/min	6 L/min	8 L/min
Mesh Nebulizer	1.77±0.2%	1.20±0.2%	1.1±0.1%	3.27±0.3%	2.35±0.3%	7.20±0.6%	6.72±0.4%
Jet Nebulizer			1.0±0.2%		1.45±0.1%	3.83±0.5%	4.49±0.3%