Mucus Retention

Retention of airway secretions is a frequent complication in critically ill patients requiring invasive mechanical ventilation (MV).This complication is often due to excessive secretion production and ineffective secretion clearance. Mechanical insufflator-exsufflator (MI-E) is a respiratory physiotherapy technique that aims to assist or simulate a normal cough by using an electro-mechanical dedicated device. A positive airway pressure is delivered to the airways, in order to hyperinflate the lungs, followed by a rapid change to negative pressure that promotes a rapid exhalation and enhances peak expiratory flows. However, there is no consensus on the best MI-E settings to facilitate secretion clearance in these patients. Inspiratory and expiratory pressures of ±40 cmH2O and inspiratory-expiratory time of 3 and 2 seconds, respectively, are often used as a standard for MI-E programming in the daily routine practice, but recent laboratory studies have shown significant benefits when MI-E setting is optimized to promote an expiratory flow bias. The investigators designed this study to compare the effects of MI-E with an optimized setting versus a standard setting on the wet volume of suctioned sputum in intubated critically ill patients on invasive MV for more than 48 hours.