| Approximately 60% of very preterm infants (< 32 weeks of gestational age) require resuscitation at birth, at which time adequate ventilation is crucial. It is difficult to create adequate gas exchange in a surfactant deficient immature lung with impaired lung liquid clearance. Therefore, many preterm infants are intubated and mechanically ventilated at birth, potentially injuring the preterm lung. We have shown that using an initial sustained inflation (SI) and applying positive pressure at end expiration (PEEP) or continuous positive airway pressure (CPAP) during mask ventilation at birth reduces the need for intubation and improves outcome in very preterm infants. Using a novel technique, phase contrast X-ray imaging in preterm rabbits, we have shown that applying SI and PEEP at birth improves uniform lung aeration and lung gas volume, which are essential for adequate gas exchange immediately after birth. However, further research is necessary to determine the optimal duration and frequency of SIs and inflating pressures (peak pressure, PEEP/CPAP) to be used. The aim of this project is to identify the most effective and least injurious combination of SIs and inflating pressures at birth in a preterm rabbit model and to evaluate this strategy non-invasively in clinical setting. We will compare combinations of SIs and inflating pressures by measuring: 1) lung function and lung aeration using plethysmography and phase contrast X-ray imaging and 2) lung injury using early response genes. The most effective strategy identified in these studies will be compared with the current ventilation strategy in a randomized clinical trial. Primary outcome will be death or chronic lung injury. Both strategies will also be evaluated by measuring lung function and other physiological parameters at birth. |
