Author ORCID Identifier

Date of Award


Degree Type


Degree Name

Master of Science (MS)


Respiratory Therapy

First Advisor

Dr. Douglas S. Gardenhire

Second Advisor

Dr. Chip Zimmerman

Third Advisor

Dr. Kyle Brandenberger


Background: Aerosol escaping to the environment during nebulization treatments is called fugitive aerosol. Placing a filter at the exhalation outlet is one way to prevent unintended inhalation of fugitive aerosol by healthcare providers. Aim: To determine the best exhalation filter in preventing fugitive aerosol from escaping to the environment. Methods: Three brands of exhalation filters were tested in our study, the Westmed filter, Airlife filter, and Microgard filter. They were attached at the exhalation outlet of the Circulaire II nebulizer with a collection filter sitting right after. Each filter was nebulized for three consecutive tests before being discarded. For each test, albuterol (2.5 mg/0.5 ml equivalent to 3 mg of albuterol sulfate) was nebulized to a simulated breathing adult patient (VT 500 ml, RR 15 BPM) by a flowmeter powered with 8 LPM for five minutes. After completion of each test, the collection filter was rinsed and gently stirred with 0.1N of HCl before being analyzed by a spectrophotometry device for the determination of fugitive dose. PROTECTION AGAINST FUGITIVE AEROSOL AMONG EXHALATION FILTERS vii Results: All types of exhalation filters allowed less than 0.4% of the nominal dose to escaped for each nebulization test. There were no differences in fugitive dose between each exhalation filter within the three nebulization tests (p >0.05), and the average of the three tests (p >0.05). There was also no difference in fugitive dose between each test for the same type of exhalation filter (p >0.05). Conclusion: Regardless of the exhalation filter tested, all offer similar protection against fugitive aerosol for the first three nebulization treatments.


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