The Science Journal of the American Association for Respiratory Care

2004 OPEN FORUM Abstracts

A Bench Study to Compare the Performance of Compressor Nebulizers and the Effect on Nebulization Times



R. Diesem, G. Voss, V. Pertelle RRT, R. McCoy RRT

Background: Compressor nebulizers are the standard of care for nebulizing medications in home care. There are a variety of products to choose from when evaluating options for purchase. Home care providers often evaluate products based on manufacturer claims and marketing material. The assumption is that these products all perform the same so purchasing decisions are based on product reliability, warranty, features and price. The objective of this evaluation is to determine the performance capabilities of several commercially available nebulizers to compare performance and the impact performance might have on treatment times.

Methods:
The first test battery consisted of four different jet nebulizer cups driven for a ten minute simulated nebulizer treatment period by five different nebulizer compressors. Each nebulizer cup was driven by each compressor a total of three times. The pressure and flow of the system (nebulizer cup and compressor combination) was recorded after 5 minutes of use and at the end of the simulated treatment period. The combined flow rate and pressure output drop during the course of the treatment was calculated for each combination. The second test battery consisted of running a nebulizer cup to run out using the highest and lowest output compressors using the most restrictive and least restrictive nebulizer cups. The test used 3 ml of saline solution for the nebulized fluid. Each combination of nebulizer compressor and cup was run until sputtering started; the nebulizer cup was than tapped three times on the side and allowed to run until sputtering commenced again. The run out time was recorded for each nebulizer system.

Results:
Nebulizer system flow rates varied a total of 75% across the systems tested from a low of 3.9 lpm to a high of 6.88 lpm with an average flow of 5.6 lpm. Nebulizer system pressures varied a total of 167% across the systems tested from a low of 8.7 psi to a high of 23.2 psi with an average pressure of 14.5 psi. Nebulizer run out times ranged from a low of 5 minutes 15 seconds to a high of 15 minutes. Interestingly the most restrictive nebulizer cup (4.7 lpm average flow) nebulized the saline solution in half the time required by the least restrictive nebulizer cup (6.3 lpm average flow).

Conclusion
: Different compressor nebulizers have varying performance capabilities related to pressure generation, flow and the response to different resistances simulating different nebulizers’ cups. These performance differences can vary nebulization times and affect the amount of medication a patient receives in a fixed time period. Providers of nebulizers and therapy should know the performance capabilities of the compressor nebulizers to determine the optimal therapy time to deliver the prescribed medication.