Crossover study of assist control ventilation and neurally adjusted ventilatory assist

Some studies of infants with acute respiratory distress have demonstrated that neurally adjusted ventilator assist (NAVA) had better short-term results compared to non-triggered or other triggered models. We determined if very prematurely born infants with evolving or established bronchopulmonary dysplasia (BPD) had a lower oxygenation index (OI) on NAVA compared to assist control ventilation (ACV). Infants were studied for 1 h each on each mode. At the end of each hour, blood gas analysis was performed and the OI calculated. The inspired oxygen concentration (FiO₂), the peak inflation (PIP) and mean airway pressures (MAP) and compliance were averaged from the last 5 min on each mode. Nine infants, median gestational age of 25 (range 22-27) weeks, were studied at a median postnatal age of 20 (range 8-84) days. The mean OI after 1 h on NAVA was 7.9 compared to 11.1 on ACV (p = 0.0007). The FiO₂ (0.36 versus 0.45, p = 0.007), PIP (16.7 versus 20.1 cm H₂O, p = 0.017) and MAP (9.2 versus 10.5 cm H₂O, p = 0.004) were lower on NAVA. Compliance was higher on NAVA (0.62 versus 0.50 ml/cmH₂O/kg, p = 0.005).

NAVA compared to ACV improved oxygenation in prematurely born infants with evolving or established BPD. What is Known: • Neurally assist ventilator adjust (NAVA) uses the electrical activity of the diaphragm to servo control the applied pressure. • In infants with acute RDS, use of NAVA was associated with lower peak inflation pressures and higher tidal volumes. What is New: • This study uniquely reports infants with evolving or established BPD, and their results were compared on 1 h each of NAVA and assist controlled ventilation. • On NAVA, infants had superior (lower) oxygen indices, lower inspired oxygen concentrations and peak and mean airway pressures and higher compliance.