Comparison of breath-enhanced to breath-actuated nebulizers for rate, consistency, and efficiency

To evaluate differences between three new-generation nebulizers-Pari LC Star (Pari Respiratory Equipment; Mississauga, ON, Canada), AeroEclipse (Trudell Medical International, London, ON, Canada), and Halolite (Medic-Aid Limited, West Sussex, UK)-in terms of rate and amount of expected deposition as well as the consistency of the doses delivered.

The in vitro performance characteristics were determined and then coupled to the respiratory pattern of seven patients with cystic fibrosis (age range, 4 to 18 years) in order to calculate expected deposition. The Pari LC Star and AeroEclipse were characterized while being driven by the Pari ProNeb Ultra compressor (Pari Respiratory Equipment) for home use, and by a 50-psi medical air hospital source. The Halolite has its own self-contained compressor. Algorithms for the rate of output for the inspiratory flow were developed for each device. Patient flow patterns were divided into 5-ms epochs, and the expected deposition for each epoch was calculated from the algorithms. Summed over a breath, this allowed the calculation of the estimated deposition for each patient's particular pattern of breathing.

The rate of deposition was highest for the Pari LC Star and lowest for the Halolite. Rate of deposition was independent of respiratory pattern for the Pari LC Star and AeroEclipse, but proportional to respiratory rate for the Halolite. The differences between the Pari LC Star and AeroEclipse were less when driven by the 50-psi source. The AeroEclipse had the least amount of drug wastage. As designed, the Halolite delivered a predetermined amount of drug very accurately, whereas expected deposition when run to dryness of the other two devices had significant variations.

To minimize treatment time, the Pari LC Star would be best. To minimize drug wastage, the AeroEclipse would be best. To accurately deliver a specific drug dose, the Halolite would be best.