Pressure ulcers (PU) represent a major health issue because of their high incidence and of their important consequences. There is an important risk of pressure ulcer acquisition for ICU patient with acute organ failure.

Specific risk factors identified in ICU are immobility, which accentuates the effects of friction and shears, as well as mechanical ventilation and the use of vasopressors.

A repositioning schedule is a guideline for pressure ulcer prevention, but repositioning frequency remains unknown.

Adaptation of the repositioning schedule to pressure ulcer risk assessment using Braden scale should decrease emergence of pressure ulcer. This could limit their important consequences for ICU patients which add to their brittle clinical condition (infection, increased length of stay, mortality…).

This study will assess feasibility, efficacy and tolerance of a repositioning schedule applied to ICU adult patients. The repositioning schedule will be daily adapted to pressure ulcer risk of the patient assessed with Braden scale.

If results of this pilot study show improvement by the application of the repositioning schedule, they will argue the realization of a multicenter randomized clinical trial. This larger study will assess the expected decrease of pressure ulcers incidence due to the schedule and of its benefit-risk ratio.

This is a one-center prospective pilot study which includes two one-month consequential periods:

• During the first period, care will be delivered according usual practice. It is an observational phase.
• The second period will begin with medical and nurse staff training. Then, care will be delivered according the repositioning schedule. It's an interventional phase.

The procedure will be prescribed every day on patient's prescription by the doctor in charge (that will be filed with medical record).

- During the two periods: Every morning, inclusion and non-inclusion criteria will be sought for every patient intubated for at least 24 hours. This evaluation will be made by a nurse during daily medical staff meeting.

Eligible patients will be informed. Their consent will be collected and they will be included in the study. Patient characteristics (age, gender, BMI, simplified acute physiology score SAPS II, Sequential Organ Failure Assessment (SOFA) Score, length of mechanical ventilation, length of stay and mortality in ICU) will be taken from the PMSI. Those data are usually daily collected.

During the second period: data about Braden scale, positioning schedule, different positions applied, possible adverse events during positioning and presence of pressure ulcer will be collected by caregivers and nurses caring the patient.

Those data will be collected on the "daily positioning sheet" made available in patient's room. Skin condition will be evaluated on the 28th day, or when leaving ICU wall, or at death if it occurs before. Clinical research technician will control concordance between repositioning data and position applied by caregivers and nurses and those recommended by the schedule.

Inclusion Criteria:

• Expected duration of invasive ventilation: more than 24 hours at inclusion;
• No pressure ulcer at inclusion (using of a tool developed from the European Pressure Ulcer Advisory Panel);;
• Information of the patient, or if it is not possible information of his relatives, or emergency procedure if contacting relatives is not possible. Consent document will then be signed by the patient as soon as he is able to do.

Exclusion Criteria:

• Under than 18 years;
• Pregnant woman;
• protected adult as defined by the law;
• Person without any health insurance;
• patient recruited in any other interventional research studying mobilization or positioning of the patient and/or pressure ulcer prevention and/or being in exclusion period of any other research if concerned;
• patient admitted in ICU for the multiple trauma management;
• patient concerned by a medical decision to limit active therapies at the time of potential inclusion.

It is planned to share data to argue the realization of a multicenter trial on this theme. This data can be shared by different way including e-mail transfer.