Particle size distribution for jet nebulizers commonly employed in the pediatric clinical setting

ABSTRACT Two jet nebulizers employed in the pediatric practice were evaluated under usually prescribed operating conditions to determine the particle size distribution of their aerosols. The nebulizers, Hudson Up Draft II (UPD) and Bennett Twin (BT), were operated with different flow rates and volumes of fill, using normal saline (NS) and gentamicin (G) diluted in normal saline. Thus, six nebulization conditions were built. Particle size was measured by laser diffraction. There were wide differences in mass median diameter (MMD), geometric standard deviation (GSD), and percentage of aerosol mass contained in particles less than 5.3 microns (μ), 4 μ, 3 μ and 1.9 μ between the systems. The MMD for UPD nebulizer driven by a flow rate of 5.5L/min and loaded with NS (system A) or G (system E) were not different, 4.4 μ and 4.4 μ, respectively. The MMD for BT nebulizer driven by a flow rate of 5.5L/min and loaded NS (system C) or G (system F) was 7.7 and 8.7 μ, respectively. The percentage of aerosol mass contai...