Update on patient-triggered ventilation.

Physiologic studies have demonstrated short-term benefits of triggered ventilation over conventional ventilation. The results of the randomized trials are disappointing. Meta-analysis has highlighted that the only significant difference in outcomes on PTV compared with conventional ventilation is a shorter duration of weaning. A few of the trials included infants with meconium aspiration syndrome and congenital pneumonia, but most infants randomized had RDS. In addition, a high proportion of the infants included in the meta-analysis were from two trials in which the SLE 2000 and airway pressure triggering system were mainly used. We cannot confidently conclude that in a population of infants with another respiratory disorder or even in those with RDS supported by an alternative triggering system, a different result might have been achieved. In addition, the benefits of PTV demonstrated in physiologic studies are largely related to achieving synchronized ventilation. In none of the randomized trials was any attempt made to determine if the infants were breathing synchronously with their ventilators. Before dismissing PTV for use in the management of infants with acute respiratory distress, an appropriately designed trial needs to take place. Essential, before any such trial, is identification of optimum method of PTV delivery, which may be disease specific.