Abstract

Combination inhaled corticosteroids (ICs) are the primary treatment prescribed for patients with asthma; however, voice problems are also associated with ICs. In this study, 32 rabbits were assigned randomly to one of five experimental groups: baseline, induction, induction control, reversibility, and reversibility control. The baseline group received no treatment and larynges were obtained following quarantine. Rabbits belonging to experimental groups received IC treatment twice a day until trained raters noted visible vocal fold changes during endoscopy, which was performed every 2 weeks. When changes were observed, animals were euthanized, and the larynges were harvested from the experimental induction group and the corresponding control group. The remaining rabbits entered a withdrawal phase wherein ICs were discontinued, and endoscopy was performed every 2 weeks until visual-perceptual ratings indicated a return to baseline. Subsequently, all excised larynges underwent benchtop phonation trials to acquire aerodynamic data relating to vocal fold functioning at phonation onset. Analysis included 17 rabbits from the previous phase of the study and showed an increase in phonation threshold pressure (PTP) and phonation threshold flow (PTF) following IC use compared to the control groups. Rabbits in the experimental withdrawal group showed lower PTP and PTF compared to the induction group, but still greater values than the control groups. These results indicate IC-related adverse vocal effects may decrease after treatment is withdrawn but might not reverse completely. These findings indicate a trend toward recovery when ICs are withdrawn but lay critical groundwork for future studies involving asthma management and IC-driven voice disorders.

Degree

MS

College and Department

David O. McKay School of Education; Communication Disorders

Rights

https://lib.byu.edu/about/copyright/

Date Submitted

2024-05-29

Document Type

Thesis

Handle

http://hdl.lib.byu.edu/1877/etd13224

Keywords

asthma, inhaler, corticosteroid, phonation threshold pressure (PTP)

Language

english

Included in

Education Commons

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