Respiratory function and the mechanism of cough in Duchenne Muscular Dystrophy

Abstract

bjective: To describe the relationship between the inefficiency of the mechanism of cough and the degradation of respiratory function in patients with Duchenne Muscular Dystrophy (DMD). Methods: A documentary study carried out from the following databases: Pubmed, Cochrane and Scielo. The terms “Duchenne muscular Dystrophy”, “Respiratory Function” and “Peak Cough Flow” were used as descriptors, individually or in association. Articles that addressed other types of muscular dystrophy or were not suitable for the aim of the study were excluded. Results: The search resulted in 294 articles and of these, 40 were selected. The findings were divided into four categories: “Normal mechanism of cough”; “Mechanism and peak cough flow in DMD”; “Pulmonary complications” and “Physiotherapy approach and treatment”. In patients with DMD, the efficiency of cough occur secondary to progressive muscle weakness, making them susceptible to respiratory tract infection. The production of effective cough is a predictor of pulmonary function in these patients. The goals of treatment should include the increase of both maximum insufflation capacity as the peak cough flow and the correction of hypopnea and hypercapnia. Conclusion: The efficiency of the mechanism of cough is associated with both vital capacity and maximum insufflation capacity as with the strength of respiratory muscles to produce peak cough flow. These are issues to be addressed in treatment of patients with DMD and constant evaluation during the course of illness should guide the intervention.