Low versus standard calorie and protein feeding in ventilated adults with shock: a randomised, controlled, multicentre, open-label, parallel-group trial (NUTRIREA-3).

BACKGROUND:The optimal calorie and protein intakes at the acute phase of severe critical illness remain unknown. We hypothesised that early calorie and protein restriction improved outcomes in these patients, compared with standard calorie and protein targets. METHODS:The pragmatic, randomised, controlled, multicentre, open-label, parallel-group NUTRIREA-3 trial was performed in 61 French intensive care units (ICUs). Adults (≥18 years) receiving invasive mechanical ventilation and vasopressor support for shock were randomly assigned to early nutrition (started within 24 h after intubation) with either low or standard calorie and protein targets (6 kcal/kg per day and 0·2-0·4 g/kg per day protein vs 25 kcal/kg per day and 1·0-1·3 g/kg per day protein) during the first 7 ICU days. The two primary endpoints were time to readiness for ICU discharge and day 90 all-cause mortality. Key secondary outcomes included secondary infections, gastrointestinal events, and liver dysfunction. The trial is registered on ClinicalTrials.gov, NCT03573739, and is completed. FINDINGS:Of 3044 patients randomly assigned between July 5, 2018, and 8 Dec 8, 2020, eight withdrew consent to participation. By day 90, 628 (41·3%) of 1521 patients in the low group and 648 (42·8%) of 1515 patients in the standard group had died (absolute difference -1·5%, 95% CI -5·0 to 2·0; p=0·41). Median time to readiness for ICU discharge was 8·0 days (IQR 5·0-14·0) in the low group and 9·0 days (5·0-17·0) in the standard group (hazard ratio [HR] 1·12, 95% CI 1·02 to 1·22; p=0·015). Proportions of patients with secondary infections did not differ between the groups (HR 0·85, 0·71 to 1·01; p=0·06). The low group had lower proportions of patients with vomiting (HR 0·77, 0·67 to 0·89; p<0·001), diarrhoea (0·83, 0·73 to 0·94; p=0·004), bowel ischaemia (0·50, 0·26 to 0·95; p=0·030), and liver dysfunction (0·92, 0·86-0·99; p=0·032). INTERPRETATION:Compared with standard calorie and protein targets, early calorie and protein restriction did not decrease mortality but was associated with faster recovery and fewer complications. FUNDING:French Ministry of Health.