We investigated the inflating pressures (Pinfl, the difference between peak inspiratory pressure and positive end-expiratory pressure) in infants receiving volume targeted ventilation.

Data were collected and analysed from 195 infants. Median Pinfl was determined before each blood gas (n = 3425). Ventilator parameters and blood gases were compared between periods when Pinfl was <5 mbar and periods when it was higher.

1-hour periods when median Pinfl was <5 mbar occurred in 30% of the babies and were associated with similar tidal volumes and minutes ventilation as periods with higher Pinfl. Babies triggered more ventilator inflations, had more spontaneous breaths and lower oxygen requirement when Pinfl was low. There was no difference in blood gases when Pinfl was <5 mbar or when it was higher.

Episodes of low inflating pressure occur frequently in babies receiving volume targeted ventilation, but they do not lead to changes in blood gases.