To investigate whether using a respiratory function monitor (RFM) during mask resuscitation of preterm infants reduces face mask leak and improves tidal volume (V_T).

Infants receiving mask resuscitation were randomized to have the display of an RFM (airway pressure, flow, and V_T waves) either visible or masked.

Twenty-six infants had the RFM visible, and 23 had the RFM masked. The median mask leak was 37% (IQR, 21%-54%) in the visible RFM group and 54% (IQR, 37%-82%) in the masked RFM group (P = .01). Mask repositioning was done in 19 infants (73%) of the visible group and in 6 infants (26%) of the masked group (P = .001). The median expired V_T was similar in the 2 groups. Oxygen was provided to 61% of the visible RFM group and 87% of the RFM masked group (P = .044). Continuous positive airway pressure use was greater in the visible RFM group (73% vs 43%; P = .035). Intubation in the delivery room was done in 21% of the visible group and in 57% of the masked group (P = .035).

Using an RFM was associated with significantly less mask leak, more mask adjustments, and a lower rate of excessive V_T.