The Science Journal of the American Association for Respiratory Care

2008 OPEN FORUM Abstracts

AN IN-VITRO EVALUATION OF AEROSOL DRUG DELIVERY WITH CONTINUOUS NEBULIZATION IN SIMULATED MECHANICALLY VENTILATED PEDIATRICS

Arzu Ari1, Essam A. Aljamhan1, Robert Harwood1, James Fink2



Background: Jet nebulizers (JN) are commonly used for continuous nebulization during mechanical ventilation. Consistency of output between nebulizers and delivered drug mass at different target drug delivery outputs have not been reported. The purpose of this study was to evaluate the accuracy and consistency of JN in delivering continuous albuterol in a model of pediatric mechanical ventilation.

Methods: JN (Misty Finity, Cardinal) was placed 6 in from the "Y" and operated continuously 2.5 L/min O2 with Albuterol sulfate formulated to 10 mg/hr and 15 mg/hr per label. A ventilator (Galileo, Hamilton Medical: Vt 100 mL, PEEP 5 cmH2O, frequency 20/min, biasflow 2 lpm, Tinsp 1 sec, and descending flow) with a heated humidified circuit was attached to a 5 mm ID ETT and pediatric lung model. Nebulizers were operated for 15 min, with drug collected for 5 min intervals on filter distal to ETT (n=3). Drug was eluted and analyzed by spectrophotometry (276 nm). Descriptive statistics and repeated measures analysis of variance were performed (p<0.05).

Results: Gravimetric output (mL ± SD) varied between nebulizers from 0.17 to 0.44 mL (p<0.05) but was consistent for each unit at 5 min intervals. Calculated output was less than label at 10 and 15 mg/hr (4.6 ± 1.5, and 4.2 ± 0.2, respectively; p<0.05).

Conclusion: During continuous nebulization, output varied between nebulizers and delivered dose was not proportional to change from 10 to 15 mg/hour.