The Science Journal of the American Association for Respiratory Care

2007 OPEN FORUM Abstracts

RAPID DELIVERY OF BRONCHODILATOR MEDICATION IS POSSIBLE USING A BREATH-ACTUATED SMALL VOLUME NEBULIZER AS AN ALTERNATIVE TO EXTENDED DELIVERY OF MEDICATION BY LARGE VOLUME NEBULIZER

J. P. Mitchell2, D. P. Coppolo1, C. C. Doyle2, M. W. Nagel2, K. J. Wiersema2

Background: Inhaled beta-2 adrenergic agonist bronchodilators are often given to patients with severe reversible airways disease by continuous nebulization in extended treatments. However data are limited as to whether or not shorter, but higher concentration delivery is as an effective treatment modality. The development of a new breath-actuated nebulizer (AeroEclipse®-II, Monaghan Medical Corp., Plattsburgh, NY (AEII-BAN)) provided an opportunity to compare the two treatment methods in a laboratory study before undertaking a clinical comparison. We investigated the delivery of diluted generic respirator solution albuterol by a widely used continuous jet nebulizer (MiniHeart® Hi-Flo, Westmed Corp., Tucson, AZ (CONT) with that from the AEII-BAN.

Method:
The continuous nebulizers (n=5) were operated with 8 L/min air supplied at 50 psig with a 20-mL fill (albuterol concentration of 0.5 mg/mL). A similar number of AEII-BANs were operated with ca. 8.0 L/min air at 50 psi with a 1-mL fill (albuterol concentration of 5 mg/mL). Aerosol from both nebulizers was sampled onto electret filters using a breathing simulator mimicking small child use (250-mL tidal volume, inspiratory/expiratory ratio 1:2, rate 12 cycles/min) until onset of sputtering. Assay for albuterol was undertaken by UV spectrophotometry. In a parallel study, droplet size distributions were determined by laser diffractometry, so that the fine droplet fraction (mass % < 4.7 µm diameter) likely to penetrate to the airways of the lungs (FDF) could be determined.

Results:
Values of FDF for the AEII-BAN and CONT were 78.4% and 62.0% respectively. The AEII-BAN delivered 758 ± 36 µg as fine droplets after 4-min (delivery rate of 190 ± 9 µg/min), compared to 180 ± 76 µg in the same period by CONT (delivery rate of 45 ± 19 µg/min).

Conclusions: The faster delivery rate from the AEII-BAN/high albuterol concentration modality (un-paired t-test, p < 0.001) may offer an important clinical alternative to CONT/low concentration treatment modality.