After major surgery, fluid overload is associated with an increase of morbidity and mortality.

Fluid administration should therefore be given wisely. However, there is a paucity of monitor to predict preload dependence in paediatric anaesthesia.

The aim of this study is to determine if VTI variation, measured through the suprasternal window, with a cardiac doppler probe, can predict preload dependence.

Indeed, cardiac probe are present in most operating room and suprasternal window is reachable in most surgical case, which should allow VTI monitoring for the vast majority of our patient.

Inclusion Criteria:

• Patient under 18 admitted to paediatric operating room for a surgical intervention, an endoscopy, an interventional radiology procedure or an imagery and needing a general anaesthesia.

Exclusion Criteria:

• Condition preventing a suprasternal ultrasound (tracheostomy, spinal immobilization, suprasternal bandage)
• Pathology disturbing respiratory variation of left ventricular stroke volume (PAH, constrictive pericarditis, pericardial effusion, right ventricular dysfunction, complex congenital heart disease, aortic coarctation, patent ductus arteriosus
• Every medical condition where Berry's rule of fasting compensation could be unsafe (anuric kidney failure, oedema, heart failure with reduce left ventricular ejection fraction, patient under vasoactive drugs
• Opposition to the participation in the study
• Pregnant women
• Patient with no security coverage
• Inability to determine baseline cardiac output

Patient under 18 admitted to paediatric operating room for a surgical intervention, an endoscopy, an interventional radiology procedure or an imagery and needing a general anaesthesia