It is currently recommended to start enteral nutrition early in intensive care unit children receiving invasive or non-invasive mechanical ventilation.

Gastrointestinal intolerance is the main complication related to early enteral feeding in intensive care unit patients, characterized by gastroparesis with delayed gastric emptying that may lead to regurgitations, vomiting, pulmonary aspiration, and potentially increased risk of ventilator-associated pneumonia (VAP).

Residual gastric volume (RGV) measurement had been recommended to monitor the tolerance to enteral nutrition in mechanically ventilated patients receiving early enteral feeding.

Nevertheless, several studies have challenged the usefulness of such RGV monitoring, showing that it led to reduced caloric intake without any benefits in terms of reducing the occurrence of vomiting and the incidence of VAP.

This lack of relationship between RGV monitored using gastric suctioning and the occurrence of regurgitation, aspiration and pneumonia may reflect the inaccuracy of the aspiration method used for the measurement of the RGV, as it has been reported in adult patients.

Gastric ultrasonography is a non-invasive and easy-to-use tool allowing accurate preoperative assessment of gastric contents, based on both qualitative examination of the gastric antrum and calculation of gastric content volume. Ultrasound examination of the antrum could therefore constitute an alternative to gastric suctioning for the monitoring of RGV in intensive care unit patients.

This prospective study aims to assess the reliability of the RGV monitoring based on gastric suctioning compared to ultrasound technique. Secondary endpoint is to assess whether increased gastric volume, aspirated or calculated by ultrasound, is an independent risk factor of regurgitation and / or vomiting.

Inclusion Criteria:

• Children hospitalized in intensive care unit, requiring invasive or non-invasive mechanical ventilation for a foreseeable duration > 48 hours.
• Enteral nutrition that has been started for more than 48 hours and less than 7 days.
• Age between 37 weeks of post conceptual age and 18 years.
• Parental consent or consent by the person having parental authority.

Exclusion Criteria:

• Abdominal surgery ≤ 1 year
• History of esophageal, gastric, duodenal, or pancreatic surgery
• Enteral nutrition via jejunostomy or gastrostomy.
• Any situation contraindicating the mobilization of the child in the right lateral decubitus position (uncontrolled hemodynamic instability, unstable neurological injury ...)

This study will be conducted in pediatric intensive care unit patients