Activity and Fatigue of the Respiratory Muscles and Pulmonary Characteristics in Post-Polio Patients

Background: Early diagnosis of respiratory impairment in Post-Polio (PPS) patients may delay respiratory decline and future need of invasive respiratory aids. Objectives: To compare pulmonary function measures, maximal respiratory pressure and activity levels and fatigue of respiratory muscles between patients with PPS and healthy controls. Design: Cross-sectional study. Setting: Hadassah physical medicine and rehabilitation department, Jerusalem. Patients: Patients with PPS (N=12; 6 males; age 62.1±11.6 years) able to walk for 6 minutes without human assistance; age-matched healthy subjects (N=12; 4 males; age 62.2±6.5 years). Intervention: None. Measurements: A body plethysmograph was used to quantify forced expiratory volume in the first second of a forced expiratory maneuver, vital capacity, slow vital capacity, Residual Volume (RV), Total Lung Capacity (TLC), and Thoracic Gas Volume (TGV). Also, RV to TLC ratio is calculated. A manometer was used to measure Maximal Inspiratory Pressure (MIP) and Maximal Expiratory Pressure (MEP). A spirometer was used to measure Maximal Voluntary Ventilation (MVV). Surface electromyography (sEMG) recorded diaphragmatic muscle activity during rest and while performing MVV.