Comparison of Automated Oxygen Control With and Without Automated Pressure Control in Preterm Ventilated Infants.

This is a volume-targeted mode of ventilation aimed at delivering the set tidal volume of gas by automatically adjusting the peak inspiratory pressure (PIP) on a breath-by-breath basis. Theoretically this should minimise variation in tidal volume delivery as lung compliance and the infant's condition changes. This function is achieved by an automated servo-controlled mechanism. The upper PIP limit can be set by the clinician as a safety mechanism.

Volume-Controlled ventilation (VCV) is a type of 'volume targeted' mode. It aims to target be supported the desired tidal volume by delivering a set volume (chosen by the clinician) irrespective of the underlying lung mechanics. The ventilator will generate whatever peak inspiratory pressure is necessary to deliver this volume. There is constant inspiratory flow pattern (a square flow waveform) and peak volume and inspiratory pressure delivery are achieved at the end of inspiration. During the 'control period' of 12 hours without VG, infants will using VCV A/C (assist control) as is our current clinical standard.