NAVA VentilationImpact of NAVA Ventilation on Brain Oxygenation and Perfusion in Children With Congenital Heart Disease

Positive intra-thoracic pressures induced by mechanical ventilation can negatively impact right heart hemodynamics by restricting systemic venous return and increasing right ventricular afterload. These consequences may be detrimental in patients with a restrictive right ventricular physiology and in patients with single ventricle physiology. NAVA (Neurally Adjusted Ventilatory Assist) ventilation decreases intra thoracic pressures compared to conventional ventilation modes. Brain perfusion is both a hemodynamic indicator and a prognostic factor in cardiac postoperative care. Diffuse Correlation Spectroscopy (DCS) coupled with Near Infrared Spectroscopy (NIRS) is a new technology that allows monitoring, in addition to brain tissue oxygenation, changes in brain blood flow.

This physiological study aims to evaluate the impact of NAVA mode ventilation on cerebral and systemic hemodynamics in post-operative cardiac surgery patients with preload dependant right ventricle or with passive venous return to the lungs . This prospective cross-over study will include 30 patients.

Once stabilized in intensive care, patients will undergo 2 periods of ventilation in NAVA mode and conventional mode separated by a 30-minute washout period, in a random order.

For each period the following information will be collected: changes in cerebral blood flow and cerebral oxygenation, hemodynamic parameters including cardiac output and oxygen transport and ventilatory parameters.