Neurally Adjusted Ventilatory Assist for Neonates With Congenital Diaphragmatic Hernias

Overview

Congenital Diaphragmatic Hernias (CDH) are typically repaired surgically in the first few days of a neonate's life. Following surgical repair, infants usually require ventilatory support to ensure adequate oxygenation. Traditionally assist control ventilation (ACV) has been used to support neonates with CDH. Due to delivering a fixed pressure of oxygen, ACV has been associated with barotrauma and long-term lung damage. A more recent approach to ventilation is non-invasive neurally adjusted ventilatory assist (NIV-NAVA). NIV-NAVA uses electrical signals of the diaphragm to deliver a proportional pressure of oxygen. Our dual-centre randomised cross-over trial aims to investigate the efficacy of NIV-NAVA compared to ACV for supporting neonates with CDH.

Background: Congenital Diaphragmatic Hernias (CDH) are typically repaired surgically in the first few days of a neonate's life. Following surgical repair, infants usually require ventilatory support to ensure adequate oxygenation. Traditionally assist control ventilation (ACV) has been used to support neonates with CDH. Due to delivering a fixed pressure of oxygen, ACV has been associated with barotrauma and long-term lung damage. A more recent approach to ventilation is non-invasive neurally adjusted ventilatory assist (NIV-NAVA). NIV-NAVA uses electrical signals of the diaphragm to deliver a proportional pressure of oxygen. Evidence suggests that NAVA may reduce physiological parameters associated with lung pressure and hence reduce the risk of iatrogenic lung injury. Aims: Our aim is to compare the oxygenation index (OI) of neonates with CDH, ventilated with ACV and NIV-NAVA. The OI is calculated as the fractured of inspired oxygen x mean airway pressure x partial pressure of oxygen/100. The oxygenation index is used as a marker of hypoxic respiratory failure in infants with CDH and forms the basis of the criteria to administer nitric oxide. Methods: Our investigation is a dual-centre randomised cross-over trial. Infants will be identified and parents counselled in the first few days following delivery. Neonates that meet inclusion criteria will be randomised to receive either NIV-NAVA or ACV first, followed by the other method of ventilation. Infants will be stabilised on ACV one-hour prior to entering the trial. On entry into the trial, they will receive 4-hours of each ventilatory method with a 20-minute stabilisation break in between.