Respiratory variability in mechanically ventilated patients
Increased respiratory pattern variability is associated with improved oxygenation. Pressure support (PS) is a widely used partial assist mechanical ventilation (MV) mode, in which each breathing cycle is initiated by flow or pressure variation at the airway due to patient inspiratory effort. Neurally Adjusted Ventilatory Assist (NAVA) is relatively new and uses the electrical activity of the diaphragm (Eadi) to deliver ventilatory support proportional to the patient’s inspiratory demand. We hypothesize that respiratory variability should be greater with NAVA compared with PS.