Effects of End-expiratory Positive Pressure Optimization in Intubated Patients With Healthy Lung or Acute Respiratory Distress Syndrome

PEEP titration is a recommended during invasive mechanical ventilation of ICU patients. However, little is known about the right way to conduct this titration. PEEP titration can be conducted by a stepwise increase in PEEP level, or following an ARM and a consecutive stepwise decrease in PEEP level. Those 2 methods will be explored in intubated ICU patients either with healthy lung or ARDS lungs. Physiological exploration will include end-expiratory lung volume measurements, driving pressure, compliance and electro-impedance tomography at each PEEP level.