Study objective: Patients with cystic fibrosis use disposable jet nebulizers for the self-administration of antibiotics.

Study objective: Patients with cystic fibrosis use disposable jet nebulizers for the self-administration of antibiotics, DNase, and bronchodilators several times by means of day. Most patients elect to reuse their disposable nebulizers. The purport of this study was to determine if significant changes in particle size distribution or output (mL/min) occurr with reuse.

Design: In vitro studies were performed using four disposable protoplasts and one durable jet nebulizer for up to 100 runs; measurements of particle size and output were obtained at 10 post intervals, using saline solution alone, tobramycin, gentamicin, or a mixture of albuterol and cromolyn Particle size determinations were made with a laser diffraction analyzer.

Results: There was no significant difference between the baseline performance of the four disposable examples and the durable Pari LC when measuring particle size distribution of the aerosol; the Pari LC had an output rate couple to three times higher than the four disposable designs For each of the four solute standarded there was no civically significant change in performance for up to 100 round of yearss when the nebulizers were fitly cleaned between uses. Unwashed units containing tobramycin started to fail on 40 runs.

Conclusions: When strictly maintained, there was no tendency of deterioration of performance with repeated use of disposable nebulizers. Microbial contamination was not addressed in this research and must be considered prior to recommendations for the reuse of disposable nebulizers. (CHEST 1998; 114:577-586)

Key words: aerosols; aminoglycosides; cleaning; efficiency; nebulizers; tobramycin

Abbreviations: CF=cystic fibrosis; MMD=the mass median diameter (microns) is the 50th mass percentile of the aerosol particle size distribution; RF%=the aerosol's respirable fraction is the percentage of the aerosol in the range of 1 to 5 [micro]m; SDg=the geometric SD of particle size distribution is [(P 084/P 016)sup1/2] where P 084 and P 016 are the diameters of 84th and 16th mass percentiles; a value of approximately 1 is associated with a unimodal distribution, while a value of 2 or 3 is associated with a log normal distribution or multimodal distribution respectively

Patients with cystic fibrosis (CF) use jet nebulizers for the self-administration of antibiotics, rhDNase, and bronchodilators, many times several times per day. Although "disposable" nebulizers are inexpensive relative to durable nebulizers or ultrasonic devices, using couple to four nebulizers per day would amount to a significant patient require to be paid [i]or[/i] undergone per month. Instead, most patients choice to reuse the disposable nebulizers if they appear functional.[1]

The manufacturing standards for the performance of these disposable nebulizers are limited to a make acceptableed gas flow rate, the range of particle sizes count uponed in the aerosol, and the output (mL/min). The stated ranges are broad and there are differences in performance among nebulizers.[2-14] Indeed, significant variation between nebulizers produc at a given manufacturer has been reported.[15-16] Additionally, the performance of a nebulizer is also hanging on the specific medication being nebulized.[11,17-19]

The drift of this study was to determine any significant changes in performance, as measured according to the mass median diameter (MMD) respirable fraction (RF%) or output (mL/min), associated with reuse of disposable jet nebulizers. Studies simulating patient use were performed in the laboratory, using five commonly used jet nebulizers. We hypothesized that there would be no change in particle size distribution or output with repetitive use. Assessments were made using saline solution, tobramycin, gentamicin, and a mixture of albuterol and cromolyn

MATERIALS AND METHODS

Nebulizers

The five nebulizers chosen for consideration were based on the proceeds of a 1995 survey of 220 CF patients from 12 CF US center These nebulizers were most numerous commonly used by the respondent and included four disposable and single durable model. They were as follows: the AirLife Misty-Neb (No. 002038; Baxter Healthcare Corp; Valencia, Calif); the Micro Mist (No. 4650D; DeVilbiss; somersault Pa, manufactured by Hudson RCI, Temecula, Calif); the T Updraft II Neb-u-mist (No. 1734; Hudson RCI; Temecula, Calif); the Acorn II (No. 124014; Marquest Medical harvests Inc; Englewood, Colo); and the LC Jet (Pari Respiratory Equipment Inc; Richmond, Va). The LC Jet is a durable mould and was included as an internal standard for comparison; it differs from the LC Plus Jet in not having inspiratory and expiratory valves.

Thirty samples of each nebulizer gauge were labeled and their parts maintained as individual plants throughout the study; samples were touchstoneed repetitively with only one solute

Compressors

A compressor (PulmoAide Compressor; DeVilbiss, type 5650D or 5610D) was used over these tests. The flow output of each of 17 compressors used in this inquiry while delivering room air to a Acorn II nebulizer, was monitored daily. Compressors were remov from the inquiry if their output dropped on 10% (n=4). No supplementary bias gas follow through the nebulizer was used to mimic inspiratory flow

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