RT Journal Article
SR Electronic
T1 Medical Nebulizer Performance: Effects of Cascade Impactor Temperature
JF Respiratory Care
FD American Association for Respiratory Care
SP 1077
OP 1082
VO 50
IS 8
A1 Yue Zhou
A1 Amitkumar Ahuja
A1 Clinton M Irvin
A1 Dean A Kracko
A1 Jacob D McDonald
A1 Yung-Sung Cheng
YR 2005
UL http://rc.rcjournal.com/content/50/8/1077.abstract
AB BACKGROUND: During operation of a jet nebulizer, the temperature of the nebulizer outlet could decrease by more than 10°C, depending on the nebulizer type and operating conditions, such as driving flow rate and fill volume. The droplet size distribution generated from the nebulizer can be measured by a cascade impactor. However, when the cascade impactor is operated at ambient room temperature, the droplets could evaporate because of the temperature difference between the nebulizer outlet and the body of the impactor. METHODS: An 8-stage cascade impactor was used to measure the particle size distribution from 4 different types of jet nebulizer (LC Plus, Side-Stream, VixOne, and Micromist) in 2 temperature conditions: ambient (22°C) and low (10°C). Two different formulations, albuterol (aqueous solution) and budesonide (suspension), were used. RESULTS: There was a significantly larger (p < 0.05) mass median aerodynamic diameter and smaller respirable fraction for each nebulizer with the impactor at low temperature than with the impactor at ambient temperature. The mass median aerodynamic diameter of the nebulizers with the impactor operating at low temperature appeared 15–130% larger than with the impactor operating at ambient temperature, for both formulations. The respirable fraction also changed from 10% when the impactor was operated at low temperature to 65% when the impactor was operated at ambient temperature. CONCLUSION: The results provide important information for the use of a cascade impactor to measure the particle-size distribution of nebulizer aerosols.