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 H2 O, p = 0.017) and MAP (9.2 versus 10.5 cm H2 O, p = 0.004) were lower on NAVA. Compliance was higher on NAVA (0.62 versus 0.50 ml/cmH2 O/kg, p = 0.005).

CONCLUSION: 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.