In Vitro Comparison of Aerosol Delivery Using Different Face Masks and Flow Rates With a High-Flow Humidity System

Abstract

BACKGROUND: Aerosol drug delivery to infants and small children is influenced by many factors, such as types of interface, gas flows, and the designs of face masks. The purpose of this in vitro study was to evaluate aerosol delivery during administration of gas flows across the range used clinically with high-flow humidity systems using 2 aerosol masks. METHODS: A spontaneous lung model was used to simulate an infant/young toddler up to 2 y of age and pediatric breathing patterns. Nebulized salbutamol by a vibrating mesh nebulizer positioned at the inlet of a high-flow humidification system at gas flows of 3, 6, and 12 L/min was delivered via pediatric face masks to a pediatric face mannequin attached to a filter. Aerosol particle size distribution exiting the vibrating mesh nebulizer and at the mask position distal to the heated humidifier with 3 flows was measured with a cascade impactor. Eluted drug from the filters and the impactor was analyzed with a spectrophotometer (n ‫؍‬ 3). Statistical analysis was performed by analysis of variance with a significant level of P < .05. RESULTS: The inhaled mass was between 2.8% and 8.1% among all settings and was significantly lower at 12 L/min (P ‫؍‬ .004) in the pediatric model. Drug delivery with pediatric breathing was greater than with infant breathing (P ‫؍‬ .004). The particle size distribution of aerosol emitted from the nebulizer was larger than the heated humidified aerosol exiting the tubing (P ‫؍‬ .002), with no difference between the 3 flows (P ‫؍‬ .10). CONCLUSIONS: The flows of gas entering the mask and breathing patterns influence aerosol delivery, independent of the face mask used. Aerosol delivery through a high-flow humidification system via mask could be effective with both infant and pediatric breathing patterns.

Effect of Nebulizer Designs on Aerosol Delivery During Non-Invasive Mechanical Ventilation: A Modeling Study of In Vitro Data

“…Aerosol delivery in non-invasive ventilation (NIV) was proven to be of benefit and has been well studied [5,[7][8][9][10][11]. However, the effect of the change of design of nebulizers with the same mechanism on delivery has not been studied much.…”

Comparison of Aerosol Delivery by Face Mask and Tracheostomy Collar

“…Aerosol delivery via a face mask has been studied in the laboratory, but mainly in infant/pediatric models. 8,9 These studies showed that mask design, flow, and breathing pattern each independently had an effect on aerosol deposition.…”

Aerosol Delivery With Different Interfaces: Redirecting Our Focus

“…Thanks to the work of Lin et al, 1 presented in this issue of RESPIRATORY CARE, clarification of details surrounding the selection of aerosol interface with high-flow systems for infants and children has finally come to fruition. As aerosol technology has evolved, so too has evidence-based knowledge and recommendations for clinical practice.…”

“…This implies that higher doses (or higher concentrations) of medications may be required with increased HFNC flow (Ͼ 3 L/min) or with a mask (Ͼ 12 L/min). 1 Other considerations than need to be taken into account include mask design. The incidence of drug delivered to the eyes, face, and nose is impacted by the type, size, shape, and dead space of the mask.…”

“…The incidence of drug delivered to the eyes, face, and nose is impacted by the type, size, shape, and dead space of the mask. 1,3 In addition, the selection of mask size and the amount of leak around it affect medication delivery. 4 As a clinician considers the many factors that affect aerosol delivery, those impacting delivery via a heated-and-humidified mask or nasal cannula need to be considered.…”