Determination of differential effects of 3 positions on lung function in preterm infants.

Preterm infants are moved throughout different positions while nursed in the neonatal nursery. The aim of this study is to determine the effects of 3 commonly used positions on lung function in those infants requiring ventilatory support. The positions to be used include prone (lying on the stomach), supine (lying on the back), and ¼ turn from prone (lying on stomach with one side up). By looking at the ventilation distribution during positioning, this study will give clinicians an idea of how to optimise ventilation non-invasively using positioning. Factors we are investigating that are important in making this decision are optimal lung aeration and oxygenation. This trial will use recently developed scientific technology including lung scanning (EIT) and a new form of breath washout (MBW using sulphur hexafluoride) to give us a better understanding of the effectiveness of positioning. Data on EIT and MBW will be downloaded directly onto a computer and the data analyst will be blinded to the positions.