Weaning of mechanical ventilation is an important phase of ICU (Intensive Care Unit) patient hospitalization. Patients have to pass a spontaneous breathing trial, can have a phase of pause with mechanical ventilation before extubation and then can be weaned of invasive mechanical ventilation. Spontaneous breathing trial can be performed with a T-Tube or with Pressure support without PEEP (End Expiratory Positive Pressure) . Duration of spontaneous breathing trial range from 30 minutes to 120 minutes. Some clinicians performed an arterial blood gases at the end of the spontaneous breathing trial but this practice is not really defined and clearly explained in recommendations. Patients can benefit of ventilation support after extubation like non invasive pressure support or high flow nasal canulae. The procedure can be very different from a center to another, especially for arterial blood gases at the end of spontaneous breathing trial. Our aim is to observe in a multicenter study the daily practice of weaning of mechanical ventilation especially for arterial blood gases.

Inclusion Criteria:

• Older than 18 years
• first attempt of weaning of mechanical ventilation

Exclusion Criteria:

• withholding of life sustaining therapies
• spontaneous breathing trial unsuccessful

Patients hospitalized in intensive care unit with invasive mechanical ventilation, first attempt of weaning of mechnical ventilation