Table 1.

Factors determining aerosol delivery⁶

Aerosol factors	Patient factors
Particle size distribution	Adherence with treatments
Aerosol density	Tidal volume
Hygroscopic properties	Respiratory rate
Viscosity and surface tension	Inspiratory flow rate
Suspension vs. solution	Breath‐hold time
	Upper airway anatomy
	Lower airway obstruction
	Age
	Cognitive and physical abilities