Efficacity and Safety of Mechanical Insufflation-exsufflation on ICU

Critically ill and intubated patients on mechanical ventilation (IMV) often present retention of respiratory secretions, increasing the risk of respiratory infections and associated morbidity. Endotracheal suctioning (ETS) is the main strategy to prevent mucus retention, but its effects are limited to the first bronchial bifurcation.

Mechanical in-exsufflation devices (MI-E) are a non-invasive chest physiotherapy (CPT) technique that aims to improve mucus clearance in proximal airways by generating high expiratory flows and simulating cough. Currently there are no studies that have specifically assessed the effects of MI-E in critically ill and intubated patients. Thus, the aims of this study are to evaluate efficacy and safety of MI-E to improve mucus clearance in critically ill and intubated patients.

Controlled randomized, cross-over, single blind trial conducted at University Hospital of Bordeaux (France).

Inclusion criteria: Patients (\>18 yo) intubated \[internal diameter (ID) 7 to 8\], sedated \[Richmond Agitation Sedation Scale (RASS) -3 to -5\], connected to IMV at least 48 h and expected IMV of at least 24h.

Exclusion criteria: Lung disease or pulmonary parenchyma damage, respiratory inspired fraction of oxygen (FiO2) \>60% and/or positive end-expiratory pressure (PEEP) \> 10 centimetres of water (cmH2O) and/or hemodynamic instability (mean arterial pressure (MAP) \< 65 millimetres of mercury (mmHg) although use of vasopressors\] , hemofiltered patients through a central jugular catheter, patients on strict dorsal decubitus by medical prescription, and high respiratory infectious risk.

Design: All patients will receive CPT followed by ETS twice daily. However, patients will randomly receive in one of the sessions an additional treatment of MI-E before ETS. MI-E treatment consists in 4 series of 5 in-expiratory cycles at +/- 40 cmH2O, 3 and 2 sec of inspiratory-expiratory time and 1 sec pause between cycles.

Variables: Mucus clearance will be assessed through wet volume of suctioned sputum through a suction catheter connected to a sterile collector container. Pulmonary mechanics will be measured before, after and 1 h post-intervention through a pneumotachograph (PNT). Peak expiratory flow (PEF) generated by MI-E will be continuously measured through a PNT. Hemodynamic measurements will be recorded before, after and 1 h post-intervention.

Eligibility Criteria:
Inclusion criteria :

* Patients over 18 years old.
* Patents endotracheally intubated (tubes between 7mm and 8mm of internal diameter).
* Invasive mechanical ventilation \> 48h
* Invasive mechanical ventilation expected \> 24h
* RASS between -3 and -5

Exclusion criteria :

* Lung disease with pulmonary parenchyma injury or diseases where mechanical insufflation-exsufflation use is not recommended (eg: emphysema, pneumothorax, pneumomediastinum, hemoptyses, airway instability, acute barotrauma).
* Hemofiltered patients through a central jugular catheter.
* Respiratory instability (FiO2) \>60% and/or (PEEP) \> 10cmH2O, and/or hemodynamic instability (MAP) \< 65mmHg although use of vasopressors)\] instability
* Patients on strict dorsal decubitus by medical prescription.
* High risk infection patients (eg: tuberculosis, H1N1) that cannot be disconnected from IMV.