Influence of nebulizer type with different pediatric aerosol masks on drug deposition in a model of a spontaneously breathing small child.

BACKGROUND The performance of nebulizers varies with the design type as well as the breathing patterns of various age groups. The present study quantified aerosol delivery using spontaneously breathing parameters of a small child (2-4 years) by a lung simulator to determine the influence of nebulizer type, actuation mechanisms, and pediatric aerosol masks. METHODS Three types of nebulizer (constant-output, breath-enhanced, and breath-actuated nebulizer) and 3 masks (standard pediatric mask, the Fish mask, and a valved mask) were chosen for the testing. The actuation mechanism of the breath-actuated nebulizer was tested by manual synchronization with inspiration, breath actuation, and continuous nebulization. The nebulizer performance was determined by determining mass median aerodynamic diameter and analyzing drug deposition distal to the trachea (inhaled mass), on the face, on the mask, residual drug in the nebulizer, and the time of nebulization. The quantity of salbutamol deposited was determined by spectrophotometry (276 nm). RESULTS Mass median aerodynamic diameter was similar across nebulizers. Breath-actuated nebulization generated a lower inhaled dose and higher nebulization time than continuous nebulization (P = .001). Breath synchronized aerosol generation, whether breath-actuated or manually actuated, yielded 10-20 times lower inhaled mass than continuous nebulization (0.1-0.6% vs 5-11%, respectively). The AeroEclipse, operated continuously, delivered greater inhaled dose than the LC Plus (P = .025). Higher inhaled dose was achieved with the Fish mask than standard or valved mask, with all nebulizers tested (P = .001). CONCLUSIONS In this model using ventilatory parameters associated with a 2-4-year-old child, breath-actuated nebulization was not as effective as continuous nebulization. Aerosol mask design can impact inhaled drug dose across the range of nebulizers tested.