Impact of Early Low-Calorie Low-Protein Versus Standard Feeding on Outcomes of Ventilated Adults With Shock

Among critically ill patients requiring mechanical ventilation and catecholamines for shock, nearly 40% to 50% die, and functional recovery is often delayed in survivors. International guidelines include early nutritional support (≤48 h after admission), 20-25 kcal/kg/d at the acute phase, and 1.2-2 g/kg/d protein. These targets are rarely achieved in patients with severe critically illnesses. Recent data challenge the wisdom of providing standard amounts of calories and protein during the acute phase of critical illness. Studies designed to improve enteral nutrition delivery showed no outcome benefits with higher intakes. Instead, adding parenteral nutrition to increase intakes was associated with longer ICU stays and more infectious complications. Studies suggest that higher protein intakes during the acute phase may be associated with greater muscle wasting and ICU-acquired weakness. The optimal calorie and protein supply at the acute phase of severe critical illness remains unknown. NUTRIREA-3 will be the first trial to compare standard calorie and protein feeding complying with guidelines to low-calorie low-protein feeding potentially associated with improved muscle preservation, translating into shorter mechanical ventilation and ICU-stay durations, lower ICU-acquired infection rates, lower mortality, and better long-term clinical outcomes. This multicentre, randomized, controlled, open trial will compare, in patients receiving mechanical ventilation and treated with vasoactive agent for shock two strategies for initiating nutritional support at the acute phase of ICU management (D0-D7): early calorie/protein restriction (6 kcal/kg/d/0.2-0.4 g/kg/d, Low group) or standard calorie/protein targets (25 kcal/kg/d/1.0-1.3 g/kg/d, Standard group). Patients in both groups will receive enteral or parenteral nutrition appropriate for their critical illness. Two alternative primary end-points will be evaluated: all-cause mortality by day 90 and time to discharge alive from the ICU. Second end-points will be calories and proteins delivered, nosocomial infections, gastro-intestinal complications, glucose control, liver dysfunctions, muscle function at the time of readiness for ICU discharge and quality of life at 3 months and 1 year after study inclusion.