The Science Journal of the American Association for Respiratory Care

2008 OPEN FORUM Abstracts


John M. Hughes1, Kristen L. Hess1, Christine M. Dzedzy1

Background: Metered-dose inhalers (pMDIs) are more effective when used in combination with a spacer by decreasing particle size, reducing deposition in the oropharynx and increasing the amount of medication available to the lungs.

Objective: The purpose of this study is to compare the performance of homemade spacers to commercially produced spacers.

Methods: Five types of homemade spacers made from 291ml, 500ml and 1000ml plastic bottles, paper towels rolls and toilet paper rolls were compared to a non-valved spacer (ACE), valved spacer (Optichamber Advantage), a non-electrostatic spacer (Vortex) and a pMDI without a spacer. A ventilator-driven spontaneous breathing lung model was set to deliver an inspired volume of 2.1 L, mean inspiratory flowrate of 22.42 L/min. Two puffs of albuterol were actuated into the spacers at the onset of inspiration and collected on in-line filters. The drug particles were eluded off the filters using methanol in a sonicator then quantified using UV Spectrophotometry at a detection wavelength of 275nm. A standard curve was created by diluting a stock solution to obtain the linear regression line equation. The equation was used to determine the concentration of drug from each filter. Each type of spacer was tested eight times, using a new spacer for each trial. The plastic bottles were washed with detergent to eliminate electrostatic charge.

Results: The 500ml and 291ml plastic bottles and the paper towel roll made significantly more drug available to the lungs than the three commercial spacers tested (p<0.05).

Discussion: These data suggest homemade spacers are more efficient than commercial spacers for drug delivery from a pMDI when optimized technique is employed. It is acknowledged that valves in commercial spacers are helpful when optimal technique is not employed.