none participant included

The weaning of mechanical ventilation is difficult period. This period is particularly difficult for patient with obstructive chronic respiratory disease and a long mechanical ventilation is associated with an increased risk of infectious complication, cardiac dysfunction, muscular weakness or barotromatism. No guideline is available on the ventilator mode to use during the night. In weaning period, some studies have demonstrated that nocturnal control ventilation during the weaning period improved the quality and the quantity of sleep. The hypothesis is that use of nocturnal controlled mechanical ventilation could decrease the weaning period duration and the ventilation weaning failure because of a sleep improvement.

The main objective is to compare mechanical ventilation weaning period duration according to the nocturnal ventilator mode (pressure controlled ventilation versus pressure support ventilation) in patients with an obstructive respiratory disease. A secondary objective is to evaluate the rate of weaning failure after the first extubation according to the nocturnal ventilator mode and to evaluate the sleep during the weaning period according to the nocturnal ventilator mode.

All patients with weaning criteria, spontaneous breathing test will be done. If patient is able to have spontaneous ventilation with maximum of 16 cm of H2O of pressure support, he could be included in the study. The nocturnal ventilation mode will be randomised between pressure controlled ventilation and pressure support ventilation with the same pressure support than during the day. We will follow the quality and quantity of sleep with continue polysomnography. Indeed, patients in ICU could sleep during the night but too during the day. We will compare the duration of the weaning period between the two arms.

Inclusion criteria :

• Patient with invasive mechanical ventilation (with B840 ventilator)
• Patient with ventilation weaning criteria
• Patient able to support during the day pressure support ventilation with pressure support lower than 19 cm of H2O.
• Patient with all mechanical ventilation weaning criteria for the first trial of spontaneous ventilation.
• Age > 18 years

Exclusion criteria :

• Patient with central apnoea syndrome
• Patient with narcolepsy
• Patient with metabolic encephalopathy.