Effect of Automated versus Conventional Ventilation on Mechanical Power of Ventilation – a randomized crossover clinical trial

International, multicenter, randomized crossover clinical trial in patients that were expected to need invasive ventilation > 24 hours. Patients were randomly assigned to start with a 3–hour period of automated ventilation or conventional ventilation after which the alternate ventilation mode was selected. The primary outcome was mechanical power in passive and active patients; secondary outcomes included key ventilator settings and ventilatory parameters that affect mechanical power.

data collection

Ventilation parameters were collected at baseline and at 12 consecutive time points: six time points per each ventilation mode. Inspiratory and expiratory holds were performed every 30 minutes in passively ventilated patients to measure the static ventilation pressures and to determine the absence of spontaneously breathing activity. Researchers were extensively trained and experienced in the performance of these holds and measurements [27]. At each time point, we collected the inspired and expired VT (VTi and VTe, mL), set and measured RR (breaths per minute), maximum airway pressure (Pmax, cm H2O), Pplat (cm H2O), set and total PEEP (cm H2O), set inspiratory pressure (Pinsp, cm H2O) and inspiratory time (Tinsp, sec). We also collected the rise time (Tslope, sec), inspiratory flow (L/min), FiO2 (%), etCO2 (kPa) and SpO2 (%). When each phase lasted >1 hour and patient was stable, an arterial blood gas analysis was performed. A follow–up was performed at day 28.