Ventilation and Spontaneous Breathing at Birth of Infants with Congenital Diaphragmatic Hernia

Objective

To describe the interaction of spontaneous breaths, manual ventilation, and tidal volumes (V_T) during stabilization of infants with congenital diaphragmatic hernia (CDH) in the delivery room.

Study design

We studied infants with CDH receiving respiratory support at birth. Airway pressure, flow, and volume were measured, and each breath or inflation was analyzed. Each V_T was classified as a manual inflation, a spontaneous breath, or a spontaneous breath coinciding with manual inflation on the basis of the timing of the pressure and flow waves.

Results

Twelve infants had 2957 breaths suitable for analysis, with spontaneous breathing in 11 infants (92%). The mean (±SD) proportion of manual inflations was 41% (±24%), spontaneous breaths 43% (±25%), spontaneous but coinciding with manual inflation 16% (±12%). V_T was significantly different for spontaneous breaths (3.8 ± 1.9 mL/kg), spontaneous breaths coinciding with manual inflation (4.7 ± 2.5 mL/kg), and manual inflations alone (2.6 ± 1.6 mL/kg).

Conclusions

Most infants with CDH breathed spontaneously, and manual ventilation was mostly asynchronous. We observed large differences in tidal volumes between spontaneous breaths, manual inflations, or where these coincided, with manual inflations having the lowest V_T. Monitoring the respiratory pattern of these infants could improve respiratory support.

Abbreviations: CDH, Congenital diaphragmatic hernia, CPAP, Continuous positive airway pressure, PEEP, Positive end-expiratory pressure, PIP, Peak inspiratory pressure, RWH, Royal Women's Hospital, V_T, Tidal volume