The Science Journal of the American Association for Respiratory Care

2008 OPEN FORUM Abstracts

INFLUENCE OF NEBULIZER TYPE, POSITION AND BIAS FLOW ON AEROSOL DRUG DELIVERY IN A MODEL OF ADULT MECHANICAL VENTILATION.

Arzu Ari1, Essam A. Aljamhan1, James Fink2



Background: The effectiveness of aerosol drug delivery during adult mechanical ventilation varies due to aerosol generator type, position in the ventilator circuit and ventilator parameters. The purpose of this study was to determine the influence of position and bias flow using a jet (JN) and a vibrating mesh (VM) nebulizer on albuterol sulfate delivery in a model of adult mechanical ventilation.

Methods: JN (Misty FinityTM, Cardinal Health) and VM (Aeroneb� Solo, Aerogen Inc) nebulizers were operated at Position 1: JN was placed 6 inches from the "Y" adapter, whereas VM was attached directly to the Y piece. In Position 2: JN was placed prior to the heated humidifier by 6 inches of 22mm tubing; while VM was placed at the inlet of the humidifier. A ventilator (Galileo, Hamilton Medical) with a heated humidifier (F&P) and 15 mm ID heated wire ventilator circuit delivered adult settings (Vt 500 mL, PEEP 5 cmH2O, RR 20/min, PIF 60L/min, Descending waveform) through an 8 mm ID ETT to an absolute filter attached to a test lung (Michigan Instruments) at bias flows of 2 and 5 lpm. Albuterol sulfate (2.5 mg) was nebulized in each condition (n=3), eluted from the filter and analyzed by spectrophotometry (276 nm). A 3-way factorial ANOVA was used (p<0.05).

Results: The percentage of inhaled dose (mean± SD) is presented in the table below. VM was more efficient than JN at both positions (p<0.05).

Conclusion: Placement of the VM at the pre-humidifier was more efficient than placement at the Y. Aerosol delivery using the JN stayed the same at both positions.