L'insufflation-exsufflation mécanique (Cough-Assist® et Pegaso®)Â : bases physiologiques, indications et recommandations pratiques

Patients affected by restrictive respiratory insufficiency typically present with cough impairment due to respiratory muscle weakness. Beside manual cough augmentation therapies such as hyperinflation and chest compression, mechanical devices such as Mechanical Insufflation-Exsufflation (MI-E) were developed to amplify peak cough flows (PCF) in these patients. MI-E applies air insufflation into the lungs by positive pressure followed by an abrupt suctioning of air out of the lungs by negative pressure. MI-E is suggested as an adequate option to enhance cough when patients are too weak or fatigued to reach effective cough with manual assisted cough therapies. By contrast with the Pegaso® (Dima, Bologna, Italy), the Cough-Assist® MI-E device (Respironics, Murrysville, USA) was widely studied. According to local experiences and patient groups, the positive pressures reported in the literature range from +20 to +40 cmH2O and negative pressures from -30 to -60 cmH2O. MI-E may be delivered via a non-invasive interface (nose-mouth mask) or an invasive interface (tube of tracheostomy or intubation) in paediatric and adult patients. In the absence of bronchospasm, MI-E is recommended in patients with very weak respiratory muscles and severe upper airway encumbrance. Compared with manual cough augmentation therapies alone, sessions of upper airway clearance in these patients are shorter, better tolerated and more effective when MI-E is included in the therapy. Impaired bulbar function and chronic obstructive pulmonary disease are limiting factors of effectiveness of MI-E devices. The current authors suggest herein several practical recommendations for effective clinical use.