Objective: To compare conventional trigger modes (pressure and flow trigger) to neurally adjusted ventilatory assist (NAVA), a novel sensing technique, and to observe the patient-ventilator interactions during these modes.
Methods: In this prospective, crossover comparison study in tertiary care pediatric and neonatal intensive care unit, 18 patients (age from 30 weeks of postconceptional age to 16 years) needing mechanical ventilation were randomized. Three patients were excluded from the analysis because of problems in data collection. Patients were ventilated with three different trigger modes (pressure, flow, NAVA), for 10 min each. Patients were randomly allocated to six groups according to the order of trigger modes used.
Results: The primary end point was the time in asynchrony between the patient and the ventilator. Secondary end points were peak and mean airway pressures (MAP), breathing frequency, tidal volume (TV), and vital parameters during each trigger mode. The proportion of time in asynchrony was significantly shorter in the NAVA group (8.8%) than in the pressure (33.4%) and flow (30.8%) groups (P < 0.001 for both). In the NAVA group, the peak inspiratory pressure was 2 to 1.9 cmH(2) O lower than in the pressure and flow groups, respectively (P < 0.05 for both) and the breathing frequency was 10 breaths/min higher than in the pressure group (P = 0.001). There was a tendency toward a lower MAP (P = 0.047) but the mean TV was about the same (6.4-6.8 ml/kg) in all three groups (P = 0.55). There were no differences in oxygen saturation or vital parameters between the groups.
Conclusion: NAVA offers a novel way of sensing patients' spontaneous breathing and significantly improves short-term patient-ventilator synchrony in a pediatric population.
Copyright © 2011 Wiley Periodicals, Inc.