Mechanical Ventilation With Neurally-Adjusted Ventilatory Assist in Patients With ARDS

Neurally Adjusted ventilatory-Assist(NAVA) is an assisted ventilatory mode that captures the electrical activity of the diaphragm and uses it to initiate and terminate the inspiratory phase, offering inspiratory assistance in proportion to patient effort, cycle by cycle. Studies in animals and humans have shown that NAVA reduces the work of breathing and improves patient-ventilator interaction in comparison with traditional modes. Because it is an assisted mode, its use requires less sedation. The use of NAVA could contribute to the reduction of complications of prolonged mechanical ventilation in patients with Acute Respiratory Distress Syndrome (ARDS) submitted to protective ventilation with low tidal volumes and limited plateau pressure. However, there are no studies with NAVA in the acute phase of ARDS, in which assisted-controlled modes are generally used, allowing for adjustment of tidal volume and/or plateau pressure. With this project, the investigators intend to evaluate the behavior of NAVA mode in the acute phase of mechanical ventilation in ARDS patients, to assess whether this mode can be used to deliver an assisted lung protective ventilation strategy.