In intensive care, gastrointestinal dysfunction may occur in response to systemic insult. Acute gastrointestinal dysfunction (AGID) has been clinically defined by consensus and several grades of severity have been defined. Biomarkers of digestive distress have also been described in intensive care and can be measured directly in the plasma (lipopolysaccharide, intestinal fatty acid binding protein, citrulline, glucagon-like peptide-1).

Enteral nutrition is a frequent therapy in intensive care patients, and its administration is recommended. In general, nurtition is resumed early via a nasogastric tube in patients placed on mechanical ventilation. The resumption of nutrition can be seen as a "challenge" to the gastrointestinal tract, and may thus unmask underlying gastrointestinal dysfunction. Intolerance of enteral nutrition is a symptom of gastrointestinal dysfunction and is associated with poor clinical outcomes. Indeed, it is both a marker of severity by reflecting organ dysfunction and responsible for a reduction in caloric intake that can influence prognosis.

There is no consensus on the definition of intolerance to enteral nutrition. In practice, it is most often recognized because of regurgitation or vomiting, requiring reduction or discontinuation. In a recent review, the authors emphasize the need for digestive monitoring for early diagnosis of nutritional intolerance.

Gastric echography is a minimally invasive and reliable means of monitoring the gastric contents. In particular, the surface of the antrum has been validated as a way to diagnose a full stomach in intensive care. The measurement of echographic variations in gastric residue with the resumption of enteral nutrition could thus allow the early diagnosis of gastrointestinal dysfunction and food intolerance by preceding vomiting.

Our objective is to show the interest of echographic monitoring of the stomach during the resumption of enteral feeding for the diagnosis of nutritional intolerance. As nutritional intolerance is a symptom of gastrointestinal dysfunction, we will also study this phenomenon by measuring the associations between echographic data, clinical data and biomarkers of gastrointestinal dysfunction.

Inclusion Criteria:

• Next-of-kin/health care proxy has not objected to the inclusion of the patient
• Patient admitted to intensive care
• Predicted duration of MV > 48 hours
• Predicted start of enteral nutrition
• Time to the initiation of enteral nutrition and orotracheal intubation < 36 hours

Exclusion Criteria:

• Person subject to a measure of legal protection (curatorship, guardianship)
• Pregnant, parturient or breastfeeding women
• Minors
• Non echogenic patient or without an exploitable echographic window
• History of gastric or esophageal surgery
• Limitations of care

Patients admitted to the ICU for whom enteral nutrition is planned