Predicting Fluid Responsiveness During Shock in Newborns and Infants by End-expiratory Occlusion Test

Inclusion Criteria: * Newborn and infant \<2 years. * Born at or near term (\> 36 weeks of amenorrhea). * Hospitalized in pediatric and neonatal intensive care. * Requiring the use of invasive mechanical ventilation. * In a state of shock defined by a cardio-circulatory dysfunction associating arterial hypotension, an alteration in organ perfusion, one or more organ dysfunctions or vasopressor's requirement. Clinical signs retained: heart rate ≥ 90th percentile associated with at least one sign of peripheral hypoperfusion represented by a a capillary refill time ≥ 3sec, or the presence of mottling or coldness of the extremities or urine output ≤ 0.5ml / kg / h or disturbance of consciousness. * The practitioner in charge of the patient has decided to perform volume expansion. * Non-opposition expressed by the holders of parental authority. Exclusion Criteria: * Any serious and urgent clinical hemodynamic situation, the management of which would be delayed by inclusion in the protocol. * Patient with unoperated congenital heart disease. * Patient in spontaneous or non-invasive ventilation or with spontaneous ventilatory cycles in invasive ventilation. * Patient in prolonged cardiac arrest (\> 5min) or refractory. * Patient under venous-arterial extracorporeal membrane oxygenation. * Refusal of the holders of parental authority to exploit the collected data.