Acute Effects of Mechanical Insufflation-Exsufflation on Cough Peak Flow, Chest Wall Volumes, and Breathing Pattern of Patients With Amyotrophic Lateral Sclerosis

BACKGROUND: Mechanical insufflation-exsufflation (MI-E) consists of increasing expiratory air flow, thereby promoting an increase in cough peak flow (CPF) and secretion clearance. Respiratory impairment, characterized by reduced lung volumes and ineffective cough, is the major cause of morbidity and mortality in patients with amyotrophic lateral sclerosis (ALS). This study aimed to assess the acute effects of MI-E on CPF and chest wall compartmental and operational volumes in patients with ALS. METHODS: Ten ALS subjects (6 males) were studied by optoelectronic plethysmography (OEP) to assess the immediate effects of MI-E on CPF, chest wall volume variations and their distribution in the chest wall compartments, breathing pattern, and shortening velocity of the respiratory muscles before, during, and after the application of MI-E. RESULTS: No differences were observed in the CPF analysis between time points (pre, MI-E, post). A significant increase in CPF (P = .01) was obtained immediately after the application of MI-E in subjects with spinal-onset ALS (n = 7). No significant differences in total and compartmental lung volumes and chest wall operational volumes were observed between pre MI-E (quiet breathing), during MI-E (after coughs 1, 2, and 3), and post MI-E time points. CONCLUSIONS: The application of the MI-E technique may increase CPF in individuals with spinal ALS. However, no significant changes in total thoracic volumes, total and compartmental chest wall volumes, or changes in breathing patterns in the participants in our sample after the application of the technique were observed.