Leak during term neonatal CPAP stabilisation: does resuscitation device design affect delivered PEEP - a bench study.

Abstract

Background: Mask leak is common during newborn resuscitation, impacting delivered ventilation. Less is known about the effect of leak during assisted spontaneous breathing with continuous positive airway pressure (CPAP).

Aim: Compare CPAP performance in the presence of leak of two T-piece resuscitation devices, with differing design-imposed resistances: high resistance Neopuff and low resistance rPAP.

Methods: Devices were tested on a term dynamic lung model (compliance 1.0 mL/cmH₂O, tidal volume (VT) 23 mL) at three incremental leak levels and set positive end expiratory pressure (PEEP) 5 cmH₂O, 7 cmH₂O and 9 cmH₂O. Continuous leaks were generated by differing-length tubes open to atmosphere. Measured parameters were mean pressure, fluctuations around set pressure (∆P), VT and leak flow.

Results: 2437 breaths were analysed (1216 rPAP, 1221 Neopuff). Leak reduced PEEP, with the largest reduction at the highest leak and 9 cmH₂O set PEEP (Neopuff 2.6 cmH₂O vs rPAP 7.0 cmH₂O). Higher delivered PEEP was associated with higher leak flows (Neopuff 4.4 L/min vs rPAP 8.2 L/min, 9 cmH₂O set PEEP). VT reduced with Neopuff compared with rPAP (Neopuff 18 mL vs rPAP 23.2 mL, no leak, 9 cmH₂O set PEEP) and was affected by delivered PEEP.

Conclusion: The delivered support differed between devices in the presence of leaks. rPAP maintained pressures closer to the set PEEP value at all leak levels, and higher leak flows were seen with the maintained distending pressure. Neopuff's higher resistance led to reductions in VT that were more pronounced at low leak levels.