Submitted by Desmond Chan, SRT, Harry Kanathasan, SRT, Sherry Said, SRT, Tanvi Patel, SRT
Neurally Adjusted Ventilatory Assist (NAVA) is used as an additional adjunct to assist in improving ventilation in pediatric patients and is a useful continuous respiratory effort measurement tool. It improves synchrony between patient effort and the ventilator by using the electrical activity of the diaphragm (Edi) to deliver a breath (Lee, Shin, Jung, Kim & Kim, 2019). To do so, NAVA delivers a breath based on the amplitude of the ventilatory signal from the patient, therefore allowing the patient to govern their own respiratory support. There are multiple benefits of NAVA outlined for treating the neonatal and pediatric population. Below are five studies that demonstrated the strengths of NAVA, which include the vast age range of usefulness for NAVA, the various conditions it can be used for, improved patient-ventilator synchrony and a reduction in harmful ventilation settings.
In a study completed by Beck, Reilly, Grasselli, Mirabella, Slutsky, Dunn & Sinderby (2009), conventional ventilation and NAVA (both invasive and non-invasive) were compared in infants of 36 weeks gestational age and younger. The infants that were intubated were supported by either conventional non-invasive ventilation or non-invasive NAVA upon extubation. Beck et al. (2009) found that NAVA improved patient-ventilator interactions in low birth weight infants regardless of underlying respiratory illness.
In another prospective randomized cross-over study conducted by Vignaux, Grazioli, Piquilloud, Bochaton, Karam, Levy-Jamet, Jaecklin, Tourneux, Jolliet & Rimensberger (2013), researchers explored the asynchrony during non-invasive ventilation compared to the asynchrony in patients receiving non-invasive NAVA. They studied six children and found that the trigger delay was a lot less in NAVA compared to the non-invasive conventional ventilation levels. This study concluded that NAVA led to superior patient-ventilator synchrony by reducing the trigger delays and the number of asynchronous events (Vignaux et al., 2013).
Gibu, Cheng, Ward, Castro & Heldt (2017) conducted a randomized, controlled observational crossover study in which 11 preterm infants on heated high flow nasal cannula (HHFNC) or nasal intermittent mandatory ventilation (NIMV) were placed on non-invasive (NIV)-NAVA. These infants ranged from 840 to 2,200 grams. They were placed on NIV-NAVA for 2-4 hours over 1-5 days. During this time, PIP, FiO2, Edi, oxygen saturations, transcutaneous PCO2 and infants’ movement were recorded. The patients’ oxygen saturation was shown to be maintained at a consistently higher level with NAVA. Gibu et al. (2017) also found that NAVA was more flexible at responding to decreases in saturation as well as frequency and length of apneic periods compared to other two modes of ventilation, and also reported that infants seemed to be more comfortable on NAVA. The study concluded that NAVA minimized PIP and FiO2, provided effective ventilation, and allowed infants to truly get their desired ventilation and assistance as required (Gibu et al., 2017).
Additionally, Crulli, Khebir, Toledano, Vobecky, Poirier & Emeriaud (2018) retrospectively studied the use of NAVA in pediatric cardiac patients, postoperatively. NAVA was used invasively on these patients and demonstrated a significant reduction in PIP and mean airway pressure (MAP). The breathing rates, arterial blood gas results and oxygenation were maintained appropriately with the use of NAVA (Crulli et al., 2018).
Lastly, in a retrospective study done by Lee, Shin, Jung, Kim & Kim (2019), a total of 115 children with a gestational age of 30 weeks or less that had survived for 72 hours were examined and studied. These children were further split into Period 1 (64 infants) and Period 2 (51 infants). Some of them have been excluded in this trial due to syndromes, malformations, or other deficiencies that they had, which were anomalies in the greater group. Infants that were intubated for greater than 6 weeks, died prior to discharge, were never extubated, or were weaned to other forms of respiratory support such as heated high flow nasal cannula (HHFNC) or NCPAP, were also excluded. In total, 16 infants in Period 1 were placed on NCPAP and 14 infants in Period 2 were placed on NIV-NAVA. The researchers found that extubation failure within 72 hours occurred with 1 infant in the NIV-NAVA group and 6 infants in the NCPAP group. This study demonstrated that NIV-NAVA helped infants tolerate extubation better than NCPAP (Lee et al., 2019).
Based on the evidence shown in the above studies, NAVA is demonstrated to be a great clinical tool in various contexts. From preterm infants to pediatric populations requiring surgical interventions, studies have demonstrated that as long as there is diaphragmatic electrical activity present, NAVA is able to improve ventilation while optimizing patient comfort and synchrony. The research regarding NAVA and its clinical use continues to grow; future research should further explore the implementation of NAVA as a potential tool for weaning pediatric and neonatal patients. Due to NAVA’s ability to synchronize with patient breathing patterns and facilitate accurate tidal volume delivery, it may help in accelerating the lung recovery of mechanically ventilated patients. Therefore, research can be conducted to compare the efficacy between NAVA and other modes of ventilation on improving weaning outcomes and patient’s lung function.
Beck, J., Reilly, M., Grasselli, G., Mirabella, L., Slutsky, A. S., Dunn, M. S., & Sinderby, C. (2009).
Patient-Ventilator Interaction During Neurally Adjusted Ventilatory Assist in Low Birth Weight Infants. Pediatric Research, 65(6), 663–668.
Crulli, B., Khebir, M., Toledano, B., Vobecky, S., Poirier, N., & Emeriaud,G. (2018).
Neurally Adjusted Ventilatory Assist After Pediatric Cardiac Surgery: Clinical Experience and Impact on Ventilation Pressures. Respiratory Care, 63(2), 208–214.
Gibu, C. K., Cheng, P. Y., Ward, R. J., Castro, B., & Heldt, G. P. (2017).
Feasibility and physiological effects of noninvasive neurally adjusted ventilatory assist in preterm infants. Pediatric Research, 82(4), 650–657.
Lee, B. K., Shin, S. H., Jung, Y. H., Kim, E.-K., & Kim , H.-S. (2019).
Comparison of NIV-NAVA and NCPAP in facilitating extubation for very preterm infants. BMC Pediatrics, 19(1), 298.
Vignaux, L., Grazioli, S., Piquilloud, L., Bochaton, N., Karam, O., Levy-Jamet, Y., Jaecklin, T., Tourneux, P., Jolliet, P., & Rimensberger, P. C. (2013).
Patient–Ventilator Asynchrony During Noninvasive Pressure Support Ventilation and Neurally Adjusted Ventilatory Assist in Infants and Children: Pediatric Critical Care Medicine, 14(8), e357–e364.