The NUTRIREA-4 trial will test the hypothesis that an individually tailored rehabilitation program combining nutritional therapy, physiotherapy, and physical activity and started early in the ICU then continued uninterruptedly throughout the post-ICU stay and at home after hospital discharge improves the long-term outcomes of critical-illness survivors, compared to usual care.

From ICU admission to recovery at home, the trial patients will receive either usual care or the early extended rehabilitation program. Usual care will consist in nutritional support and physiotherapy according to usual local practice in each participating ICU. The early extended program will consist of nutritional therapy, physiotherapy, and physical activity according to a standardized protocol tailored to general- and muscle-health improvements achieved in each individual patient over time.

Inclusion Criteria:

• Invasive mechanical ventilation (MV) started in the ICU within the past 24 h, or started before ICU admission with ICU admission within the past 24 h, and expected to be required for at least 48 hours after randomization
• Treatment with a vasoactive agent for shock (adrenaline, dobutamine, or noradrenaline)
• Nutritional support expected to be started within 24 h after intubation (or within 24 h after ICU admission if intubation occurred before ICU admission)
• Age 18 or older
• Patient and/or next-of-kin informed about the trial and having consented to participation in the trial. If the patient is unable to receive information and no next-of-kin can be contacted during screening for the trial, trial inclusion will be completed as an emergency procedure by the ICU physician, in compliance with French law.
• Covered by the French public health-insurance system

Exclusion Criteria:

• MV started more than 24 hours earlier
• Specific nutritional needs, such as pre-existing long-term home enteral or parenteral nutrition for chronic bowel disease
• Dying patient, do-not-resuscitate order, or other treatment- limitation decision at ICU admission
• Social circumstances hindering follow-up and telephone/video consultations (no fixed address, non-European residence)
• Inability to provide a stable personal mobile phone number (temporary number or not in the owner's name)
• Communication difficulties via telephone or video consultation (pre-existing severe hearing or visual impairment)
• Pre-existing chronic illness with life expectancy <6 months
• Pre-existing cognitive impairment
• Pre-existing spinal injury
• Inability to walk before the critical illness
• Acute or chronic neuromuscular disease
• Brain injury, e.g., due to cardiac arrest, stroke, or severe trauma
• Pregnancy, recent delivery, or lactation
• Adult under guardianship
• Correctional facility inmate
• Institutionalized patient
• Prior inclusion in a randomized trial designed to compare rehabilitation programs delivered to patients during critical illness