1. Aerosol Therapy & HFNC Natalie Napolitano, MPH, RRT-NPS, FAARC
Research Clinical Specialist
Respiratory Therapy Department
The Children’s Hospital of Philadelphia

2. Disclosures Research Relationships: Dräger Aerogen Actuated Medical
GeNO
Smiths Medical
Aerogen sponsoring me to be here

3. Objectives Aerosolized Medication Basics
Evidence for Delivery with HFNC
Can Do VS Clinically Effective
Challenge that just because we can do it does not mean we should – understand the mechanism of what you are doing

4. Factors influencing deposition
Inspiratory flow rate – this is why we should be using the same dose regardless of age – flowrate and minute ventilation weans inspired does
barrowed from J. Fink

5. Particle Size
barrowed from J. Fink

6. Deposition
barrowed from J. Fink

7. Deposition
Each drug does testing with specific nebulizer for formulation dosing.
Think twice before switching device
Particle size - hits specific area of airways – delivers intended absorption rate for therapy
For TOBI – tested with PARI, they recommend PARI for us because the particle size is more stable and smaller than regular jet nebulizer

8. Nebulizer Delivery - Jet
With standard Jet neb
barrowed from J. Fink

9. Nebulizer Delivery - Aeroneb
Comparison for 2 most common nebs used today

10. What is the Efficacy of aerosol delivery with HFNC? Go to the science
Options with HFNC Therapy:
Remove from HFNC and deliver nebulizer or MDI
Remain on HFNC and place mask over cannula
Remain on HFNC and deliver through HFNC circuit
What is the Efficacy of aerosol delivery with HFNC? Go to the science
Most elect for option 3
Option 2 is not an option for infants that are obligate nose breathers up to 4 months of age

11. Bhashyam
Bench study to evaluate the potential for delivery of aerosols (aeroneb) via nasal cannula
Adult, pediatric, and infant cannulas tested
all at 3 lpm
2 conditions: w/ & w/o spontaneous breathing
Dose quantified with filter test and loss in circuitry
Aerosol size at different points of the circuit with laser-diffraction technique
Bhashyam AR, et al. Aerosol Delivery through Nasal Cannulas: An In Vitro Study. J Aerosol Med & Pulm Drug Delivery 2008;21(2):

12. Bhashyam 2008
A, B, C measurement points of particle size

13. Bhashyam 2008
12.8%
17.5%
18.6%
Perspective - Reminder inhaled dose with aeroneb nebulizer is 36% with respirable dose of 25% ~69% delivered from inhaled dose.

14. Bhashyam 2008
Particle size and delivery amount reduces with cannula size
Concerning that particle size with infant circuit is not measurable – may all be exhaled with little deposition in airways
Half the respirable dose
VMD = volume median diameter
Dv90 = 90% volume diameter
Infant size smaller then instrument measurements

15. Perry
Bench study
Particle size and emitted dose of albuterol (aeroneb) via Vapotherm
Measured inhaled dose (filter test) and particle size (impactor)
Tested:
3, 5, & 8 lpm
3, 5, 10, & 20 lpm
5, 10, 20, & 40 lpm
Perry SA, et al. Influences of Cannula Size and Flow Rate on Aerosol Drug Delivery Through the Vapotherm Humidified High-Flow Nasal Cannula System. Ped Crit Care Med 2013;14(5):e250-e256

16. Perry
Reduction in inspired dose as flow increases

17. Perry

18. Perry
Inspirable dose significantly less than with traditional HFNC setup with same nebulizer – however flows much higher
Delivery of medication in high flow environment through small-bore tubing delivers doses lower than expected for clinical response
However, Albuterol has large therapeutic index with benefits demonstrated at doses of mg
Data is not reported out the same so it is not equally comparable

19. Sunbul
Bench study, aerosol administration to HFNC and 2 infant CPAP systems with 2 different aerogun nebulizer positions (heater and inspiratory limb close to pt)
Infant breathing and airway model
Tried to maintain 5 cmH2O for all devices:
Optiflow HFNC: 3 lpm
Carefusion Bubble CPAP: 4lpm
Carefusion SiPAP: Plow 9lpm/Phigh 2lpm
Optiflow HFNC
Bubble CPAP
SiPAP
Sunbul FS, et al. Comparison of HFNC, Bubble CPAP and SiPAP on Aerosol Delivery in Neonates: An In-Vitro Study. Ped Pulm 2015;50:

20. Sunbul

21. Sunbul - 2015 HFNC delivered most med of all 3 devices studied
Positioning at heater provides greater medication delivery
Only 2% medication delivered

22. Summary: Data does not encourage delivery of Aerosols with HFNC
Although technical successful
Dose delivered is clinically not effective
Neb with mouthpiece with 15% nominal dose
All bench studies – need more realistic flow settings
Clinical studies are needed

23. ?QUESTIONS?