A COMPARATIVE-EVALUATION OF PRESSURE-TRIGGERING AND FLOW-TRIGGERING IN PRESSURE SUPPORT VENTILATION (PSV) FOR NEONATES USING AN ANIMAL-MODEL

The triggering system in pressure support ven tilation needs to respon d rapidly, especially in neonates. The aim of this study was to compar e the effects of flow-triggered and pressure-triggered pressure suppor t ventilation on neonatal mechanical ventilation using an animal model . Respiratory flow, airway pressure, oesophageal pressure, and diaphra gmatic electromyogram were measured during pressure support ventilatio n in five anaesthetized rabbits. The animals were connected to a VIPBI RD (Bird, U.S.A.) (CPAP mode, pressure support ventilation, 5 cm H2O a nd PEEP 0 cm H2O). Flow-triggering sensitivity was set at 0.2l/min, 0. 5l/min, 1.01l/min, or 1.5l/min. Pressure-triggering sensitivity was se t at -1.0 cm H2O. Shorter trigger delay and longer pressure support ti me were observed in flow-triggering. There was also less diaphragmatic activity in flow-triggering as evidenced by the amplitude of integrat ed diaphragmatic electromyogram and negative deflection of oesophageal pressure. The findings suggest that flow-triggering will prove superi or to pressure-triggering in pressure support ventilation for neonates .