Neurally adjusted ventilatory assist (NAVA) improves patient–ventilator interaction during non-invasive ventilation delivered by face mask

Abstract

Purpose: To determine if, compared to pressure support (PS), neurally adjusted ventilatory assist (NAVA) reduces patient-ventilator asynchrony in intensive care patients undergoing noninvasive ventilation with an oronasal face mask. Methods: In this prospective interventional study we compared patient-ventilator synchrony between PS (with ventilator settings determined by the clinician) and NAVA (with the level set so as to obtain the same maximal airway pressure as in PS). Two 20-min recordings of airway pressure, flow and electrical activity of the diaphragm during PS and NAVA were acquired in a randomized order. Trigger delay (T d ), the patient's neural inspiratory time (T in ), ventilator pressurization duration (T iv ), inspiratory time in excess (T iex ), number of asynchrony events per minute and asynchrony index (AI) were determined. Results: The study included 13 patients, six with COPD, and two with mixed pulmonary disease. T d was reduced with NAVA: median 35 ms (IQR 31-53 ms) versus 181 ms (122-208 ms); p = 0.0002. NAVA reduced both premature and delayed cyclings in the majority of patients, but not the median T iex value. The total number of asynchrony events tended to be reduced with NAVA: 1.0 events/min (0.5-3.1 events/min) versus 4.4 events/min (0.9-12.1 events/min); p = 0.08. AI was lower with NAVA: 4.9 % (2.5-10.5 %) versus 15.8 % (5.5-49.6 %); p = 0.03. During NAVA, there were no ineffective efforts, or late or premature cyclings. PaO 2 and PaCO 2 were not different between ventilatory modes. Conclusion: Compared to PS, NAVA improved patient ventilator synchrony during noninvasive ventilation by reducing T d and AI. Moreover, with NAVA, ineffective efforts, and late and premature cyclings were absent.

Neonatal and Adult ICU Ventilators to Provide Ventilation in Neonates, Infants, and Children: A Bench Model Study

“…A maximum trigger delay of 100 ms, 13,14 corresponding to ϳ12.5% of the mean T I of 800 ms, 4,[15][16][17] is usually considered as acceptable in adult patients. In this study, inspiratory times of 400, 500, and 600 ms to simulate a preterm neonate, a full-term neonate, and a child were used, respectively (hereafter referred to as patient type).…”

Current concepts in acute respiratory support for neonates and children

“…NAVA has also been described in NIPPV. [20][21][22] Summary The goal of positive pressure ventilation is to provide respiratory support, while decreasing the potential for harm. Approaches such as volume ventilation, NAVA, and noninvasive ventilation techniques help achieve adequate gas exchange while possibly optimizing patient-ventilator interaction.…”

Feasibility Study on Neurally Adjusted Ventilatory Assist in Noninvasive Ventilation After Cardiac Surgery in Infants

“…2 Adult and pediatric studies showed that NAVA increases breath-to-breath variability and improves patient-ventilator synchrony and patient comfort. [3][4][5][6][7][8][9] This last improvement is also effective in NIV in adult and pediatric subjects 10,11 and in very low birthweight infants, even in the presence of large leaks. 12 To our knowledge, no previous study was designed to evaluate this ventilation mode exclusively in the postoperative period after cardiac surgery in newborns.…”