Mitigating exhalation puffs during oxygen therapy for respiratory disease

Published on Aug 5, 2021in Physics of Fluids3.514
· DOI :10.1063/5.0057227
Arshad Kudrolli38
Estimated H-index: 38
(Clark University),
Brian Chang5
Estimated H-index: 5
(Clark University)
+ 5 AuthorsWilliam McGee18
Estimated H-index: 18
(UMMS: University of Massachusetts Medical School)
Sources
Abstract
We investigate the dispersal of exhalations corresponding to a patient experiencing shortness of breath while being treated for a respiratory disease with oxygen therapy. Respiration through a nasal cannula and a simple O2 mask is studied using a supine manikin equipped with a controllable mechanical lung by measuring aerosol density and flow with direct imaging. Exhalation puffs are observed to travel 0.35 ± 0.02 m upward while wearing a nasal cannula, and 0.29 ± 0.02 m laterally through a simple O2 mask, posing a higher direct exposure risk to caregivers. The aerosol-laden air flows were found to concentrate in narrow conical regions through both devices at several times their concentration level compared with a uniform spreading at the same distance. We test a mitigation strategy by placing a surgical mask loosely over the tested devices. The mask is demonstrated to alleviate exposure by deflecting the exhalations from being launched directly above a supine patient. The surgical mask is found to essentially eliminate the concentrated aerosol regions above the patient over the entire oxygenation rates used in treatment in both devices.
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