Background European guidelines recommend 5 sustained inflations (SI) of 2–3 seconds duration for initial resuscitation of the depressed infant. Long inflations may assist a more efficient transition from liquid to air-filled lungs.

Objectives This study examines the ability of doctors of varying experience to manage a SI in two compliance settings (high versus low) and with an open or blocked pressure-relief valve (PRV), using a self-inflating bag.

Methods We investigated the number of ventilations needed to manage a successful SI (inflation time ≥5 s and volume ≥10 ml) in a manikin model with a newborn lung simulator, randomised to high or low compliance settings. Forty-three doctors participated at first study visit and thirty-four at retest after three months. We measured tidal volume (TV), inflation time, peak inflating pressure (PIP) and mean inflating pressure (MIP) during SI with an open or blocked PRV.

Results At first study visit 31/43 (72%) and at retest 21/34 (62%) (p = 0.169) doctors learned the SI technique within 3 ventilation attempts, irrespective of lung compliance setting and years of work experience. SI’s performed with a blocked versus open PRV had higher TV (27.8 vs. 22.6 ml, p₂O; p = 0.012) and MIP (28.1 vs. 22.8 cmH₂O; p < 0.001).

Conclusion Most participants managed to deliver a SI >5 s duration with a self-inflating bag in a newborn lung simulator and it was perceived easy. A blocked PRV resulted in longer SI time and higher TV and pressure when compared to an open PRV.