2001 OPEN FORUM Abstracts
PARI VS. SIDESTREAMNEBULIZER combined with TWO COMPRESSORS FOR AEROSOLIZATION OF PULMOZYME®
Bert Kesser,RRT, David Geller, MD. The Nemours Children?s Clinic, Orlando, FL.
Background: Pulmozyme (rhDNase)is a nebulized drug that reduces sputum viscoelasticity in patients with cysticfibrosis. Pulmozyme delivery with the SideStream (SS) nebulizer powered by thepowerful Invacare MobilAire (MA) compressor resulted in greater increase inFEV1 than the Hudson T- Updraft/PulmoAide combination(1), probably due to thesmaller droplet size which may reach smaller airways. However, the MA is expensive(not always covered by third party payors), and the SS may waste significantdrug due to the mouthpiece design and the constantly open venturi. Our hypotheseswere 1) breath-enhanced nebulizers produce more drug in the fine particle rangethan SideStream, and 2) the more powerful MA compressor changes the performanceof nebulizers. We evaluated the amount of Pulmozyme delivered by three differentnebulizers: Invacare Sidestream (SS), PARI LC STAR (LC*), and PARI LC+(LC+) when powered by two different compressors: the MA and the PARI PRONEBULTRA (PNU).
Methods: Each nebulizer wascharged with 2.5 ml Pulmozyme (1mg/ml). For each nebulizer/ compressor system,we measured the Mass Median Diameter (MMD) and the respirable fraction (% RF= particles < 5 microns) using laser diffraction (Malvern Spraytec). We additionallymeasured the total ?inspired? dose of drug captured on a filter during simulatedbreathing, and calculated the respirable drug dose (RDD), i.e. the product ofthe %RF and the total inspired dose. Breath simulator settings were rate of18 breaths per minute, tidal volume of 500 ml, I:E ratio of 1:1.5. Duration= time during simulated breathing from the beginning of nebulization until 1minute past the onset of sputter. Pulmozyme was assayed with spectrophotometry.We studied 3 nebulizers of each type in duplicate for both the laser and breath-simulationstudies.
|Neb/Compressor||MMD (microns)||%RF||InspiredDose (mg)||RDD (mg)||Duration(minutes)|
|SS/PNU||3.45 ± 0.13||70.8 ± 2.2||0.17 ± 0.09||0.12 ± 0.06||4.19 ± 0.2|
|LC*/PNU||3.36 ± 0.18||68.2 ± 2.8||0.68 ± 0.10||0.47 ± 0.06||7.16 ± 0.3|
|LC+/PNU||5.19 ± 0.26||48.7 ± 1.9||0.46 ± 0.10||0.22 ± 0.04||5.61 ± 0.4|
|SS/MA||1.84 ± 0.19||90.8 ± 2.6||0.14 ± 0.05||0.12 ± 0.04||3.84 ± 0.7|
|LC*/MA||2.06 ± 0.07||84.9 ± 1.4||0.43 ± 0.02||0.37 ± 0.01||4.53 ± 0.2|
|LC+/MA||2.95 ± 0.05||69.5 ± 0.8||0.35 ± 0.08||0.24 ± 0.05|
3.99 ± 0.2
Discussion: The SS producedan aerosol with an equal or smaller MMD and higher %RF vs. LC+ or LC* with eithercompressor. The MA compressor reduced treatment times and MMD, and increased%RF for all three nebulizers. However, RDD takes into account not only %RF butalso the efficiency of the device, and is a more relevant measure for comparisonof different nebulizer/compressor systems. The RDD for the LC+ and LC* were2-4 times higher with either compressor than that of the SS. Despite reducingthe MMD, the MA did not improve RDD (dose available to the lung) for the SSor LC+, and resulted in less drug being delivered by the LC*, due to increasedwaste during exhalation and increased dead volume in the nebulizers.
Conclusions: Though the SSnebulizer and the MA compressor each produced small particles in a short time,they had large drug losses during exhalation and high dead volume. The LC+/PNUand LC*/PNU are less costly and produce 2-4 times more respirable Pulmozymethan the SS/MA(1).
1) Geller DE, Pediatr Pulmonol,1998; 25: 83-87.