Patients with upper airway obstruction (UAO) experience airflow limitations during respiration that cause a sensation of struggling during breathing referred to as dyspnea. Common causes of UAO include subglottic stenosis, bilateral recurrent laryngeal nerve injury, and vocal fold trauma or scarring. Surgical interventions are highly successful in establishing an adequate airway diameter in patients with UAO;however, a distinct group of patients remain with a degree of obstruction and flow limitation even after surgical intervention. This limitation contributes to the perception of dyspnea and diminishes participation in functionally important tasks such as exercising and speaking. An intervention strategy is needed in order to enhance respiratory function and reduce dyspnea in these patients. The main objective of this project is to examine the treatment effects of an inspiratory muscle strength training (IMST) program on children, adolescents, and young adults with UAO. The motivation behind this objective is the documented success of IMST programs in the reduction of perceived dyspnea in patients with lower airway disease. It is hypothesized that IMST will increase maximum inspiratory force generation, velocity of inspiratory muscle shortening, and inspiratory muscle endurance. These improvements in inspiratory muscle function should decrease the perception of dyspnea associated with physiologic tasks that require higher respiratory drive such as exercise and speaking. It is also hypothesized that removal of the training stimulus will initiate a return of the functional outcomes to baseline values, thereby supporting the need to examine maintenance programs in order to preserve the training effects. This study will examine the effect of a four-week IMST program on pre- and post-training measures of maximum inspiratory strength, peak inspiratory flow rates, perceived dyspnea ratings during exercise and speaking, and respiratory behaviors (kinematics). The training will be completed with a hand-held inspiratory pressure-threshold trainer. Secondary measures of interest will include ventilation patterns during exercise and pause/temporal speech patterns during speaking to further understand the mechanisms by which dyspnea may be reduced during these functional tasks. Once the post-training measures are obtained, the decline in functional gains will be observed at eight weeks following training in order to quantify detraining effects in this group of patients. The training program proposed in this study is home-based and requires little cognitive load for the patient. This project has the potential to provide a non-surgical treatment option to patients with UAO that may increase their ability to participate in social activities and provide increased occupational options. This treatment also has the potential to increase physical activity level, significantly impacting on current health status and reducing the risk of chronic disease associated with inactivity and obesity. Relevance: Individuals with obstructions to breathing in the upper portion of the respiratory tract often experience breathlessness particularly during exercise and speech. This project proposes the use of a home-based training program to specifically strength the muscles of inspiration in order to ease the sensation of breathlessness during exercise and speaking. This training program has the potential to reduce social, recreational, and occupation limitations faced by individuals who have obstructions of the respiratory tract.
Individuals with obstructions to breathing in the upper portion of the respiratory tract often experience breathlessness particularly during exercise and speech. This project proposes the use of a home-based training program to specifically strength the muscles of inspiration in order to ease the sensation of breathlessness during exercise and speaking. This training program has the potential to reduce social, recreational, and occupation limitations faced by individuals who have obstructions of the respiratory tract.
