Comparison of Primary Extubation Failure Between NIPPV and NI-NAVA

Overview

Extubation failure is a significant problem in preterm neonates and prolonged intubation is a well-documented risk factor for development of chronic lung disease. Out of the respiratory modalities available to extubate a preterm neonate; high flow nasal canula, nasal continuous positive airway pressure (nCPAP) and noninvasive positive pressure ventilation (NIPPV) are the most commonly used. A recent Cochrane meta-analysis concluded that NIPPV has lower extubation failure as compared to nCPAP (30% vs. 40%) NAVA (neurally adjusted ventilatory assist), a relatively new mode of mechanical ventilation in which the diaphragmatic electrical activity initiates a ventilator breath and adjustment of a preset gain (NAVA level) determines the peak inspiratory pressure. It has been reported to improve patient - ventilator synchrony and minimize mean airway pressure and ability to wean an infant from a ventilator. However till date there has been no head to head comparison of extubation failure in infants managed on NAVA with conventional ventilator strategies. In this study the investigators aim to compare primary extubation failure rates in infants/participants managed by NIPPV vs. NI-NAVA (non invasive NAVA). Eligible infants/participants will be randomized to be extubated to predefined NIPPV or NI-NAVA ventilator settings and will be assessed for primary extubation failure (defined as reintubation within 5 days after an elective extubation).

Mechanical ventilation is needed for most preterm infants to maintain adequate oxygenation and ventilation. However the coexistence of lung immaturity, weak respiratory drive, excessively compliant chest wall, and surfactant deficiency often contribute to dependency on mechanical ventilation during the first days or weeks after birth. Prolonged mechanical ventilation is associated with high mortality and morbidities including ventilator-associated pneumonia, pneumothorax, and bronchopulmonary dysplasia (BPD). Each additional week of mechanical ventilation is reported to be associated with an increase in the risk of neurodevelopmental impairment. Reduction in the need and duration of invasive mechanical ventilation may potentially improve outcome of preterm infants. Extubation failure has been independently associated with increased mortality, longer hospitalization, and more days on oxygen and ventilatory support. It is critical, therefore, to attempt extubation early and at a time when successful extubation is likely. A recent Cochrane review compared the use of nasal intermittent positive pressure ventilation (NIPPV) with nasal continuous positive airway pressure (nCPAP) in preterm infants after extubation and found that NIPPV may be more effective than nCPAP at decreasing extubation failure. The feasibility of NAVA use has been described in neonatal and pediatric patients. Several studies cite a decrease in peak inspiratory pressures, improved synchrony in triggering, and more appropriate termination of positive pressure support. Some studies have reported lower work of breathing, PaO2/FiO2 ratios (partial pressure of oxygen/ fractional inspired oxygen)and MAP. In addition, NAVA has been used for patients who "fight the ventilator," and the synchrony improves the ability to wean. The use of NIV-NAVA in neonates has promise as a primary mode of ventilation to aid in the prevention of intubation and also maintaining successful extubation. Early extubation may be enhanced with NIV-NAVA of those neonates requiring intubation for numerous reasons. The ability to provide synchronous NIV allows clinicians the opportunity to extubate infants earlier with increased confidence than with previous post extubation support. However there is lack of scientific evidence on extubation failure rates on NI-NAVA. Trials comparing NAVA to conventional ventilators with regard to ventilator associated lung injury, ventilator associated pneumonia and decreasing duration of time on the ventilator have not yet been reported.