WHY USE VOLUME TARGETING?

Advances in neonatal care have led to significant improvement in the survival of preterm infants, but chronic lung disease (CLD) continues to be a major problem.1 Many factors have been linked to the development of CLD2 and a great deal of research has focused on those that are potentially amenable to intervention. Ventilator-induced lung injury (VILI) has been extensively studied. Initially, barotrauma was seen as being of major importance in the aetiology of VILI; however, increasing evidence has suggested that excessive volume, leading to overexpansion (volutrauma), and inadequate volume, leading to underexpansion/collapse, are more important aetiologically.3^–6

Time-cycled, pressure-limited ventilation (TCPL) has been the standard mode of ventilation for premature infants with respiratory distress syndrome (RDS) for many years. This mode became popular because of its simplicity and the benefits of being able to control time and pressure in the era before the availability of exogenous surfactant. But a major shortcoming has been the inability to deliver consistent tidal volumes; the tidal volume delivered being indirectly controlled by altering the peak inflating pressure and positive end expiratory pressure. However, the tidal volume delivery is not consistent because of variations in lung mechanics and the infant’s spontaneous breaths. Lung mechanics, in particular, change rapidly after the administration of surfactant and if the peak inflating pressure is not altered, excessive tidal volume delivery can lead to overexpansion and volutrauma.4 ,7 ,8

These concerns have led to the development of alternative ventilatory techniques and volume-targeted ventilation is one such technique which aims at minimising variation in the volume delivered to the infant. A range of new volume-targeted ventilators with microprocessor technology have been developed which allow the clinician to set the tidal volume directly.9 ,10 However, there are significant differences between the various approaches …