Editorial
Copyright ©The Author(s) 2015. Published by Baishideng Publishing Group Inc. All rights reserved.
World J Methodol. Jun 26, 2015; 5(2): 62-67
Published online Jun 26, 2015. doi: 10.5662/wjm.v5.i2.62
Neurally adjusted ventilator assist in very low birth weight infants: Current status
Hassib Narchi, Fares Chedid
Hassib Narchi, Department of Pediatrics, College of Medicine and Health Sciences, United Arab Emirates University, Al Ain PO Box 17666, United Arab Emirates
Fares Chedid, Department of Pediatrics, Al Jalila Hospital, Dubai Health Authority, Dubai PO Box 4545, United Arab Emirates
Author contributions: Both Narchi H and Chedid F had made substantial contributions to conception and design of the editorial, drafting the article or making critical revisions related to important intellectual content of the manuscript and final approval of the version of the article to be published.
Conflict-of-interest: The authors have no commercial, personal, political, intellectual, or religious conflict-of-interest to report in relation to this work.
Open-Access: This article is an open-access article which was selected by an in-house editor and fully peer-reviewed by external reviewers. It is distributed in accordance with the Creative Commons Attribution Non Commercial (CC BY-NC 4.0) license, which permits others to distribute, remix, adapt, build upon this work non-commercially, and license their derivative works on different terms, provided the original work is properly cited and the use is non-commercial. See: http://creativecommons.org/licenses/by-nc/4.0/
Correspondence to: Fares Chedid, MD, Department of Pediatrics, Al Jalila Hospital, Dubai Health Authority, Dubai PO Box 4545, United Arab Emirates. fareschedid@hotmail.com
Telephone: +971-50-4474661
Received: December 25, 2014
Peer-review started: December 30, 2014
First decision: February 7, 2015
Revised: March 7, 2015
Accepted: April 10, 2015
Article in press: April 14, 2015
Published online: June 26, 2015
Processing time: 194 Days and 4.5 Hours
Abstract

Continuous improvements in perinatal care have resulted in increased survival of premature infants. Their immature lungs are prone to injury with mechanical ventilation and this may develop into chronic lung disease (CLD) or bronchopulmonary dysplasia. Strategies to minimize the risk of lung injury have been developed and include improved antenatal management (education, regionalization, steroids, and antibiotics), exogenous surfactant administration and reduction of barotrauma by using exclusive or early noninvasive ventilatory support. The most frequently used mode of assisted ventilation is pressure support ventilation that may lead to patient-ventilator asynchrony that is associated with poor outcome. Ventilator-induced diaphragmatic dysfunction or disuse atrophy of diaphragm fibers may also occur. This has led to the development of new ventilation modes including neurally adjusted ventilatory assist (NAVA). This ventilation mode is controlled by electrodes embedded within a nasogastric catheter which detect the electrical diaphragmatic activity (Edi) and transmit it to trigger the ventilator in synchrony with the patient’s own respiratory efforts. This permits the patient to control peak inspiratory pressure, mean airway pressure and tidal volume. Back up pressure control (PC) is provided when there is no Edi signal and no pneumatic trigger. Compared with standard conventional ventilation, NAVA improves blood gas regulation with lower peak inspiratory pressure and oxygen requirements in preterm infants. NAVA is safe mode of ventilation. The majority of studies have shown no significant adverse events in neonates ventilated with NAVA nor a difference in the rate of intraventricular hemorrhage, pneumothorax, or necrotizing enterocolitis when compared to conventional ventilation. Future large size randomized controlled trials should be established to compare NAVA with volume targeted and pressure controlled ventilation in newborns with mature respiratory drive. Most previous studies and trials were not sufficiently large and did not include long-term patient oriented outcomes. Multicenter, randomized, outcome trials are needed to determine whether NAVA is effective in avoiding intubation, facilitating extubation, decreasing time of ventilation, reducing the incidence of CLD, decreasing length of stay, and improving long-term outcomes such as the duration of ventilation, length of hospital stay, rate of pneumothorax, CLD and other major complications of prematurity. In order to prevent barotrauma, next generations of NAVA equipment for neonatal use should enable automatic setting of ventilator parameters in the backup PC mode based on the values generated by NAVA. They should also include an upper limit to the inspiratory time as in conventional ventilation. The manufacturers of Edi catheters should produce smaller sizes available for extreme low birth weight infants. Newly developed ventilators should also include leak compensation and high frequency ventilation. A peripheral flow sensor is also essential to the proper delivery of all modes of conventional ventilation as well as NAVA.

Keywords: Interactive ventilatory support; Positive-pressure respiration; Diaphragm; Premature; Very low birth weight; Respiratory distress syndrome; Electrical diaphragmatic activity; Synchrony; Neural triggering

Core tip: Neurally adjusted ventilator assist (NAVA) ventilation utilizes the patient’s neural respiratory drive to synchronize ventilatory support on a breath-by-breath basis based on the infant’s ongoing needs. It appears to work well in neonates but evidence that it makes a difference in outcomes in this population has not been established so far. The majority of studies have shown no significant adverse events in neonates ventilated with NAVA nor a difference in the rate of intraventricular hemorrhage, pneumothorax, or necrotizing enterocolitis when compared to conventional ventilation. The challenge for neonatal health care providers remains the steep and prolonged learning curve for the application of NAVA.