Role of the Inspiratory Muscles on Functional Performance From Critical Care to Hospital Discharge and Beyond in Patients With COVID-19.

OBJECTIVE: The role of inspiratory muscle performance in functional performance in patients with coronavirus disease 2019 (COVID-19) is poorly understood. The purpose of this study was to perform a longitudinal examination of inspiratory and functional performance from intensive care unit (ICU) discharge (ICUD) to hospital discharge (HD) and symptoms at HD and 1 month after HD in patients with COVID-19. METHODS: Thirty patients (19 men, 11 women) with COVID-19 were included. Examination of inspiratory muscle performance at ICUD and HD was performed with an electronic manometer, which provided the maximal inspiratory pressure (MIP) and several other inspiratory measures. Examination of dyspnea and functional performance was performed at ICUD and HD with the Modified Borg Dyspnea Scale and the 1-minute sit-to-stand test (1MSST), respectively. RESULTS: The mean age was 71 (SD = 11) years, the mean length of ICU stay was 9 (SD = 6) days, and the mean length of hospital stay was 26 (SD = 16) days. Most of the patients were diagnosed with severe COVID-19 (76.7%) and had a mean Charlson Comorbidity Index of 4.4 (SD = 1.9), reflecting high comorbidity. The mean MIP of the entire cohort increased minimally from ICUD to HD (from 36 [SD = 21] to 40 [SD = 20] cm H2O), reflecting predicted values for men and women at ICUD and HD of 46 (25%) to 51 (23%) and 37 (24%) to 37 (20%), respectively. The 1MSTS score increased significantly from ICUD to HD (9.9 [SD = 7.1] vs 17.7 [SD = 11.1]) for the entire cohort but remained far below population-based reference values (2.5th percentile) for the majority of patients at ICUD and HD. At ICUD, MIP was found to be a significant predictor of a favorable change in 1MSTS performance (ß = 0.308; odds ratio = 1.36) at HD. CONCLUSION: A significant reduction in inspiratory and functional performance exists in patients with COVID-19 at both ICUD and HD, with a greater MIP at ICUD being a significant predictor of a greater 1MSTS score at HD. IMPACT: This study shows that inspiratory muscle training may be an important adjunct after COVID-19.

Novel versus Traditional Inspiratory Muscle Training Regimens as Home-Based, Stand-Alone Therapies in COPD: Protocol for a Randomized Controlled Trial.

Background: Subjects with COPD frequently develop considerable weakness and deconditioning of the inspiratory musculature, which can be corrected with inspiratory muscle training (IMT). While rehabilitation centers may be able to provide IMT as part of the rather complex management of COPD, there is currently a lack of rehabilitation services in the Czech Republic. Remote IMT may then benefit subjects with COPD who are unable to attend or do not have access to rehabilitation programs. We aim at evaluating the utility of the test of incremental respiratory endurance (TIRE) as an at-home IMT method in subjects with COPD, while comparing the effectiveness of this novel training approach to the outcomes of traditional, threshold loading IMT protocols. Methods/Design: This prospective, randomized controlled trial will comprise 8 weeks of at-home IMT sessions with remote supervision followed by 4 months of unsupervised, independent IMT. Eligible subjects will be randomly assigned to one of the following three distinct home-based IMT protocols: (1) TIRE, (2) Threshold loading, and (3) Sham training. Subjects allocated to the TIRE group will train once daily using an advanced IMT electronic system (PrO2), while the other two groups will receive threshold devices. Study outcomes will include measures of inspiratory muscle strength and endurance, pulmonary function, COPD-specific symptomatology, functional exercise capacity, surrogate markers of mortality risk, mental health status and health-related quality of life. Discussion: While we acknowledge the value of threshold loading IMT protocols, we believe that the TIRE training method has the potential to provide additional clinical benefits in COPD given its sophisticated remote tracking system and ability to modulate all aspects of muscular performance, including not only strength but also endurance, power and work capacity, allowing users to achieve considerably higher inspiratory pressures throughout the full range of inspiration when compared to other more traditionally used IMT methods.