Correlation of Maximal Respiratory Pressures with Pulmonary Function in Post-COVID-19 Patients

Abstract

Background: Post-COVID-19 patients frequently experience impaired respiratory muscle strength and reduced lung function, which may not be fully detected through spirometry alone. Objective: To investigate the correlation between maximal respiratory pressures specifically maximal inspiratory pressure (MIP) and maximal expiratory pressure (MEP) with pulmonary function parameters measured with spirometric parameters (FVC and FEV1) in individuals recovering from COVID-19 before and after pulmonary rehabilitation. Methods: This prospective cohort study included 25 post-COVID-19 patients who completed a structured pulmonary rehabilitation program. Respiratory muscle strength was assessed using MIP and MEP, while lung function was measured via spirometry (FVC and FEV1), both pre- and post-rehabilitation. Pearson correlation analysis was used to evaluate the associations between MIP-FVC and MEP-FEV1. Data collection followed ethical standards and statistical analysis was conducted using SPSS version 25. Results: Pre-rehabilitation, MIP and FVC were weakly correlated (r = 0.244, p = 0.239), and MEP and FEV1 showed no significant correlation (r = –0.175, p = 0.402). Post-rehabilitation, MIP correlated moderately with FVC (r = 0.553, p = 0.004), and MEP strongly with FEV1 (r = 0.697, p < 0.001), indicating substantial functional improvements. Conclusion: Pulmonary rehabilitation enhances respiratory muscle strength and its relationship with pulmonary function, supporting MIP and MEP as sensitive indicators of post-COVID-19 respiratory recovery.

Keywords: COVID-19, Forced Expiratory Volume, Muscle Strength, Pulmonary Function Tests, Pulmonary Rehabilitation, Pulmonary Ventilation, Respiratory Function Tests, Respiratory Muscle Training, Respiratory Muscles, Vital Capacity.