Objective The International Liaison Committee on Resuscitation has found that there is a need for high-quality randomised trials of training interventions that improve the effectiveness of resuscitation skills. The objective of this study was to determine whether using a respiratory function monitor (RFM) during mask ventilation training with a manikin reduces facemask leak.

Design Stratified, parallel-group, randomised controlled trial. Outcome assessors were blinded to group allocation.

Setting Thirteen hospitals in Australia, including non-tertiary sites.

Participants Consecutive sample of healthcare professionals attending a structured newborn resuscitation training course.

Interventions An RFM providing real-time, objective, leak, flow and volume information was attached to the facemask during 1.5 hours of newborn ventilation and simulation training using a manikin. Participants were randomised to have the RFM display visible (intervention) or masked (control), using a computer-generated randomisation sequence.

Main outcome measures The primary outcome was facemask leak measured after neonatal facemask ventilation training. Tidal volume was an important secondary outcome measure.

Results Participants were recruited from May 2016 to November 2017. Of 402 eligible participants, two refused consent. Four hundred were randomised, 200 to each group, of whom 194 in each group underwent analysis. The median (IQR) facemask leak was 23% (8%–41%) in the RFM visible group compared with 35% (14%–67%) in the masked group, p<0.0001, difference (95% CI) in medians 12 (4 to 22).

Conclusions The display of information from an RFM improved the effectiveness of newborn facemask ventilation training.

Trial registration number ACTRN12616000542493, pre-results.