Characterization of aerosol output from various nebulizer/compressor combinations

Objectives: Different commercially available nebulizers and compressors are available. However, the optimal combination for drug delivery is unknown. Methods: Flow rates of five different compressors (n = 3/compressor) tested alone and in combination with five different commercial nebulizers (n = 9 of each brand of nebulizer) were evaluated. Thereafter, the performances of the different nebulizers were evaluated using 2.5 mg albuterol solution (0 .5 mL) added to 2.5 mL saline at flow rates of 2, 3, 4, and 5 L/minute usin g a laser particle analyzer. Volume median diameter and percentage of parti cles in the respirable range (1-5 mum) were calculated from this data. Time for nebulization (in seconds) and residual volume (in milliliters) were al so recorded. Results: The mean flow rates for the compressors evaluated without a nebuli zer attached ranged from 6.6 L/minute (LifeCare Freedom-neb; LifeCare Inter national, Lafayette, CO) to 12.2 L/minute (DeVilbiss Pulmo-Aide; DeVilbiss Health Care, Somerset, PA). mow rates for the nebulizer/compressor combinat ions ranged from 2.08 L/minute (Pari LC Jet Proneb; Pari Respiratory Equipm ent, Richmond, VA) to 5.42 L/minute (Puritan Bennett Raindrop; Puritan Benn ett, Lenexa, KS/Omron Compare; Omron, Health Care,Vernon Hills, n). Using t he repeated measure ANOVA model, the interaction between flow rate and devi ce was significant (P < 0.001) for both percentage of particles in the resp irable range and log volume median diameter. It was observed that the perce ntage of particles in the respirable range for the Pari LC Jet did not incr ease across flow rates in contrast to the other 4 nebulizers. All compariso ns to the Pari LC Jet at 2 L/minute were significant. Conclusions: Marked variability exists in the flow rates among different co mmercially available compressors used for home nebulization of inhaled pulm onary medications. Different nebulizer/compressor combinations have markedl y different performance characteristics which could result in different eff icacy and safety profiles of the medications being administered via these d evices. We recommend that this type of information be used as a starting po int for selecting different nebulizer/compressor combinations. Further clin ical evaluation is warranted.