Physiologic Comparison Between NIV-NAVA and PS in Preterm Infants

Physiologic Comparison Between Noninvasive Neurally Adjusted Ventilatory Assist (NAVA) and Pressure Support (PS) in Preterm Infants

Neurally adjusted ventilatory assist (NAVA) has been shown to improve patient- ventilator interaction and reduce asynchronies. This is a short-term physiologic comparison between PSV (pressure support ventilation) and NAVA in delivering noninvasive ventilation through a nasal cannula, in premature infants postextubation. Patients will undergo a 30-min crossover trial of noninvasive PSV and NAVA, 15 minutes each. Diaphragm electrical activity (EAdi)and airway pressure (Paw) are recorded to derive neural and mechanical respiratory rate and timing, inspiratory trigger delays time of synchrony between diaphragm contraction and ventilator assistance, and the asynchrony index (AI).

Inclusion Criteria:

• preterm infants less than 32 weeks of gestational age
• intubated more than 48 hours after birth
• subjected to extubation with minimal ventilator setting (mean airway pressure < 7cmH2O + peak inspiratory pressure < 13 cmH2O + FiO2 < 0.4 + respiratory rate < 35/min)
• with informed consent from parents

Exclusion Criteria:

• with major congenital anomalies
• use of sedative or anesthetic drugs
• hemodynamic instability
• grade 3 or higher intraventricular hemorrhage
• phrenic nerve palsy