Nursing is essential in critically ill patients care but with high risk of hypoxia, especially during mobilization. Full closed-loop control ventilation is well established for her safety in unselected ventilated critical care patients with different lung conditions compared to conventional ventilation.

The aim of this study is to assess the ability of a full closed-loop control ventilation (Intellivent-ASV, TM) to reduce hypoxia during mobilization period in unselected ventilated patients.

Prospective randomized cross over study including all consecutive ventilated patient with predicted duration of ventilation > 48 hours, inspired oxygen fraction < 60% and without neuromuscular blocking agent.

Patient were randomized to be ventilated with full closed-loop control or conventional ventilation 30 minutes before the first nursing period after inclusion. The ventilator was switched in the other mode (conventional or full closed-loop respectively), 30 minutes before the following nursing period. Between this two consecutive nursing periods, ventilation mode is choosed by the attending physician.

The primary outcome was the oxygenation measured by pulse oxymetry during the nursing periods.

Inclusion Criteria:

• Invasive mechanical ventilation for expected time >48h

Exclusion Criteria:

• Pregnancy
• Neuromuscular blocking agent (discontinuous or continuous) infusion
• Inspired oxygen fraction (FiO2) setting > or = 60%
• Mobilization contraindication (hemodynamic instability, unstable vertebral trauma, etc.)
• Neurological breathing (patients with brain injury)
• Pulse oxymetry monitoring unavailable
• Expected ventilation weaning <24h after randomization.
• Moribund patients