Cardiac output measurement is one of the most frequently used haemodynamic parameter used for intensive care unit (ICU) patients. In pediatric ICU, it is often measured with echocardiography that is a non-invasive method but is operator dependant and can't provide continuous monitoring.

The goal of this clinical trial is to evaluate the feasibility of cardiac output measurement by Fick's method, non-invasive and allowing continuous monitoring, in comparison to echocardiography in pediatric intensive care unit.

Inclusion Criteria:

• Patient under 18 years old
• Patient over 10 kg
• Patient requiring intubation or intubated with a cuffed tube
• Patient requiring a central venous line in superior vena cava territory

Exclusion Criteria:

• Mechanical ventilation with leak
• Bad echogenicity preventing echocardiography
• Absence of written informed consent
• Patient not affiliated to French Health Insurance or not covered by public health insurance
• Patient with a legal protection