Abstract
Background:
Delivery of albuterol in-line with heated high flow nasal cannula (HHFNC) using a vibrating mesh nebulizer is frequently used in the hospital setting. HHFNC systems are now available for home use, however efficacy of aerosol delivery with these devices is unknown.
Methods:
An anatomically correct pediatric model of a spontaneously breathing 5-year old child was connected in series to a filter (lung dose), and to a breathing simulator (tidal volume 200 mL, breathing frequency 20, inspiratory time 0.9 s). An AIRVO 2 HHFNC system (Fisher & Paykel) was connected to an Optiflow Junior 2 XL cannula, and operated at 5 and 15 L/min. A Solo vibrating mesh nebulizer (Aerogen) was placed between the circuit and the cannula using a proprietary adapter or regular t-piece adapter. The heating chamber was modified to allow placement of the nebulizer in the dry or in the wet side of the humidifier. Four units of the nebulizers loaded with 10 mg/2 mL of albuterol were tested. Albuterol mass was measured via spectrophotometer, and reported as percentage of loading dose.
Results:
See table.
Conclusions:
Aerosol delivery in-line with a heated high flow nasal cannula system designed for home use was inefficient except when a t-piece adapter was used between the circuit and the cannula. Lower flow improved aerosol delivery for the same system.
*P = 0.002 compared to 15 L/min. #P < 0.0003 compared to other adapters for same flow. View all access options for this article.Results (X ± SD)
Flow
Proprietary adapter
T-piece adapter
Dry side of humidifier
Wet side of humidifier
5 L/min
1.07 ± 0.08
5.14 ± 0.46*#
0.16 ± 0.04
0.21 ± 0.04
15 L/min
0.81 ± 0.36
2.66 ± 0.75#
0.29 ± 0.12
0.39 ± 0.18
Get full access to this article