Randomised crossover trial of Neurally Adjusted Ventilatory Assist (NAVA) for Neonates with Congenital diaphragmatic hernias: the NAN-C study

Background Retrospective studies comparing NAVA to assist control ventilation (ACV) in neonates with congenital diaphragmatic hernia (CDH) have shown that ventilatory mode may improve respiratory parameters. Objectives To determine if infants with CDH studied post-operatively had a lower oxygenation index (OI) on NAVA compared to ACV. Methods This dual-centre randomised cross-over trial compared post-operative NAVA with ACV in infants with CDH. Infants were randomised to receive either NAVA or ACV first in a 1:1 ratio for a four hour period. At the end of each four hour period, blood gas analysis was performed and the OI calculated. The inspired oxygen concentration (FiO ₂ ), the peak inflation (PIP) and mean airway pressure (MAP) were averaged from the last five minutes on each mode. Results Eleven infants were randomised. Nine infants completed the trial. with median gestational age of 38 (range 34.6–39.3) weeks and median postnatal age of 7 (range 5–36) days. Eight had left sided CDH, six had patch repair and two had thoracoscopic repair. The mean OI after four hours on NAVA was 3.9 compared to 5.9 on ACV (p = 0.008). The Peak Edi (6.05 versus 9.86 µV, p = 0.028), PIP (17 versus 22 cm H ₂ O, p = 0.017) and MAP (8.7 versus 11.1 cm H ₂ O, p = 0.008), expiratory tidal volume (5.06 versus 9.86 mls/kg, p = 0.043) were lower on NAVA versus ACV. Two infants were randomised, but the trial was stopped due to a low Edi signal. Conclusion NAVA compared to ACV improved oxygenation postoperatively in infants with CDH. On NAVA, infants had superior (lower) oxygen indices, peak Edi, expiratory tidal volume and peak and mean airway pressures.