Randomised crossover trial of neurally adjusted ventilatory assist (NAVA) for neonates with congenital diaphragmatic hernias: the NAN-C study.

Abstract

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. The aim of this study is to determine if infants with CDH studied post-operatively had a lower oxygenation index (OI) on NAVA compared to ACV. 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 4-h period. At the end of each 4-h 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 5 min on each mode. 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 4 h on NAVA was 3.9 ± 1.8 compared to 5.9 ± 1.61 on ACV (p = 0.008). The peak Edi (6.05 ± 4.5 versus 9.86 ± 7.3 µV, p = 0.028), PIP (17 ± 6.3 versus 22 ± 5.3 cmH 2 O, p = 0.017), and MAP (8.7 ± 2.6 versus 11.1 ± 1.8 cmH 2 O, p = 0.008), expiratory tidal volume (5.06 ± 0.71 versus 9.86 ± 1.29 ml/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 lower oxygen indices, peak Edi, expiratory tidal volume and peak and mean airway pressures.