Comparison of pressure-, flow-, and NAVA-triggering in pediatric and neonatal ventilatory care.
ABSTRACT 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.
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.
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.
NAVA offers a novel way of sensing patients' spontaneous breathing and significantly improves short-term patient-ventilator synchrony in a pediatric population.
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ABSTRACT: PURPOSE OF REVIEW: Mechanical ventilation is one of the most important life support tools in the ICU, but it may also be harmful by causing ventilator-induced lung injury (VILI) and other deleterious effects. Advances in ventilator technology have allowed the introduction of numerous ventilator modes in an effort to improve gas exchange, reduce the risk of VILI, and finally improve outcome. In this review, we will summarize the studies evaluating some of the nonconventional ventilation techniques and discuss their possible use in clinical practice. RECENT FINDINGS: Proportional assist ventilation and neurally adjusted ventilator assist are able to improve patient-ventilator synchrony, possibly sleep, and may be better tolerated than pressure support ventilation; both integrate the physiological concept of respiratory variability like noisy ventilation. Experimental or short-term clinical studies have shown physiological benefits with the application of biphasic pressure modes. Some of the automated weaning algorithms may reduce time spent on ventilator and decrease ICU stay, especially in a busy environment. SUMMARY: Apart from the physiological and clinical attractiveness demonstrated in animals and small human studies, most of the nonconventional ventilator modes must prove their clinical benefits in large prospective trials before being applied in daily clinical practice.Current opinion in critical care 12/2012; · 2.67 Impact Factor