The R2D2-ICU study will be a prospective, parallel-group, open label, multicenter (6 centers) randomized controlled trial. All consecutive eligible patients will be included. Patients will be randomly assigned (1/1 ratio) to either systematic PR use (systematic use group) or restrictive PR use (restrictive use group). Patients in the restrictive PR group will be subjected to PR only in case of severe agitation defined by a RASS ≥ +3. Physical restraint will consist of wrist straps. In both groups, patients will receive standardized management for analgesia, sedation, delirium detection, weaning and early mobilization according to current guidelines. Concealment will be obtained using a computer-generated randomization scheme of various-sized blocks stratified by center, age (< or ≥ 65 years) and coma at the beginning of invasive mechanical ventilation (D0)) through a centralized 24h/24h internet service. Investigation blinded to group assignment is not feasible. In both arms, patients' arousal will be evaluated twice a day until day 14 with the use of RASS. Patients with a RASS of -5 or -4 will be considered comatose (and will not be assessed for delirium). Patients with a RASS score ≥ -3 will be assessed for delirium with the use of the CAM-ICU scale twice a day.

Physical restraint (PR) is defined by the HAS (Haute Autorité de Santé française) as the use of any intervention that prevent or limit movements capability, to protect a person from an inappropriate or a dangerous behavior. In French intensive care units (ICUs), wrist straps (and sometimes ankle straps) are frequently used to prevent self-removal of medical devices in case of agitation, which can affect about 50% of patients. A survey conducted in 121 French ICUs showed that in 82 % of ICUs, PR is used at least once during mechanical ventilation (MV) in more than 50 % of patients. In 65 % of ICUs, when PR is used, it is applied for more than 50 % of MV duration. In 29 % of ICUs, PR is used in more than 50 % of cases in awake, calm and co-operative patients. PR is started without written medical prescription in more than 50 % of patients in 68 % of ICUs. Only 21 % of ICUs have a written local procedure for PR use. In the European PRICE study (566 patients, 34 ICUs, 9 countries), the frequency of PR use varied from 0% to 100%.

The benefit of PR is not clearly established and PR could also be deleterious in this context. First, PR may leave patients with moderate to extremely stressful memory. Second, there is no demonstrated relationship between the PR rates and self-removal of medical devices. Finally, there is a complex relationship between agitation, PR use and delirium. While PR is prescribed to avoid potential risks associated with agitation, it seems to favor delirium. Delirium is a serious event in ICU patients that is independently associated with adverse outcomes in patients receiving MV. Moreover, the number of days of ICU delirium is significantly associated with increased 1-year mortality and long-term cognitive impairment in survivors.

The R2D2-ICU study will be a prospective, parallel-group, open label, multicenter (6 centers) randomized controlled trial. All consecutive eligible patients will be included. Patients will be randomly assigned (1/1 ratio) to either systematic PR use (systematic use group) or restrictive PR use (restrictive use group). Patients in the restrictive PR group will be subjected to PR only in case of severe agitation defined by a RASS ≥ +3. Physical restraint will consist of wrist straps. In both groups, patients will receive standardized management for analgesia, sedation, delirium detection, weaning and early mobilization according to current guidelines. Concealment will be obtained using a computer-generated randomization scheme of various-sized blocks stratified by center, age (< or ≥ 65 years) and coma at the beginning of invasive mechanical ventilation (D0)) through a centralized 24h/24h internet service. Investigation blinded to group assignment is not feasible. In both arms, patients' arousal will be evaluated twice a day until day 14 with the use of RASS. Patients with a RASS of -5 or -4 will be considered comatose (and will not be assessed for delirium). Patients with a RASS score ≥ -3 will be assessed for delirium with the use of the CAM-ICU scale twice a day.

Inclusion criteria :

• Patients fulfilling all the following criteria will be eligible:
• Adults ≥ 18 years
• MV expected for at least ≥ 48 hours
• Invasive MV in the ICU for a duration inferior to 6 hours
• eligible to prescription for physical contention

Exclusion criteria :

Patients meeting one of the following criteria will not be considered for inclusion:

• Documented delirium prior to ICU admission according to the CAM-ICU
• History of dementia (Mini mental test < 24)
• Alcoholic withdrawal syndrome expected
• Admission for any neurological disease including post-cardiopulmonary resuscitation (including cardiac arrest, stroke, traumatic brain injury, meningoencephalitis, and status epilepticus)
• Serious auditory or visual disorders
• Unable to understand French
• Pregnant or lactating women
• SAPS II > 65 points at screening
• Do-not-resuscitate orders (advance directives)
• No affiliation to a social security regime (beneficiary or assignee)
• Patient or person of confidence (if present at the time of inclusion) opposing the patient's participation in research
• Patient already involved in another interventional clinical research whose main objective is related to delirium

AP-HP Data Sharing Policy Data are available upon reasonable request. The procedures carried out with the French data privacy authority (CNIL, Commission nationale de l'informatique et des libertés) and the european regulation (GDPR) do not provide for the transmission of the database, nor do the information and consent documents signed by the patients. Consultation by the editorial board or interested researchers of individual participant data that underlie the results reported in the article after deidentification may nevertheless be considered, subject to prior determination of the terms and conditions of such consultation and in respect for compliance with the applicable regulations.

For all inquiries, please contact the following : drc-secretariat-promotion@aphp.fr