Patient triggered ventilation in chronically ventilator-dependent infants.

Patient triggered ventilation (PTV) has been assessed as a method of respiratory support in infants remaining ventilator-dependent beyond the 1st week of life. Sixteen preterm infants were studied who had a median gestational age of 26 weeks and postnatal age of 22 days. PTV was delivered using a ventilator incorporating an airway pressure trigger. PTV was only successfully maintained until extubation in 3 infants, failing to provide a satisfactory method of respiratory support in the remaining 13 infants after a median of 1 h (range 1-10). One of the 13 infants was persistently asynchronous at 1 h despite manipulation of inflation time. The other 12 infants, at failure of PTV, were making respiratory efforts which were inadequate to consistently trigger the ventilator. Infants in whom PTV was successful were older, more mature and of greater birth weight; the trigger delay at 1 h was significantly shorter in this group (P less than 0.05). A predictor of failure of PTV was asynchrony in the 1st h after commencing PTV (P less than 0.02). We conclude PTV incorporating an airway pressure trigger infrequently provides a useful method of respiratory support in infants who are chronically ventilator-dependent.