Data Safety and Monitoring Board 's request

To demonstrate that a strategy involving early first-line enteral nutrition is associated with improved preservation of gut mucosa integrity, as assessed based on the plasma citrulline level at H72, compared to a strategy involving early first-line parenteral nutrition

Published data suggest that enteral nutrition may be associated with improved preservation of the gut lymphoid tissues and gut immune function, as well as with decreased gut mucosa permeability, thereby diminishing the risk of organ failure. Citrulline is an amino acid produced from glutamine by small-bowel enterocytes. Plasma citrulline levels reflect functional enterocyte mass. Intestinal fatty acid-binding protein (I-FABP, also known as FABP2) is a small protein found in the cytosol of small-bowel enterocytes. Plasma I-FABP is normally undetectable and, when elevated, constitutes a reliable marker for enterocyte damage. The hypothesis underlying this ancillary study is that first-line enteral nutrition is associated with improved gut mucosa integrity and function compared to parenteral nutrition.

Inclusion Criteria:

• Invasive mechanical ventilation expected to be required more than 48 hours
• Nutrition started within 24 hours after initiation of endotracheal mechanical ventilation
• Treatment with vasoactive drug administered via a central venous catheter
• Age over 18 years
• Signed information

Exclusion Criteria:

• Abdominal surgery within 1 month before inclusion
• History of esophageal, gastric, duodenal or pancreatic surgery
• Bleeding from the esophagus, stomach or bowel
• enteral nutrition via gastrostomy or jejunostomy
• pregnancy
• Treatment-limitation decisions
• Current inclusion in a trial on comparison between enteral and parenteral nutrition