Non-invasive neurally adjusted ventilatory assist in preterm infants with RDS: effect of changing NAVA levels

Abstract

We aimed to examine the effect of changing levels of support (NAVA level) during non-invasive neurally adjusted ventilatory assist (NIV-NAVA) in preterm infants with respiratory distress syndrome (RDS) on electrical diaphragm activity. This is a prospective, single-centre, interventional, exploratory study in a convenience sample. Clinically stable preterm infants supported with NIV-NAVA for RDS were eligible. Patients were recruited in the first 24 h after the start of NIV-NAVA. Following a predefined titration protocol, NAVA levels were progressively increased starting from a level of 0.5 cmH 2 O/µV and with increments of 0.5 cmH 2 O/µV every 3 min, up to a maximum level of 4.0 cmH 2 O/µV. We measured the evolution of peak inspiratory pressure and the electrical signal of the diaphragm (Edi) during NAVA level titration. Twelve infants with a mean (SD) gestational age at birth of 30.6 (3.5) weeks and birth weight of 1454 (667) g were enrolled. For all patients a breakpoint could be identified during the titration study. The breakpoint was on average (SD) at a level of 2.33 (0.58) cmH 2 O/µV. With increasing NAVA levels, the respiratory rate decreased significantly. No severe complications occurred.Conclusions: Preterm neonates with RDS supported with NIV-NAVA display a biphasic response to changing NAVA levels with an identifiable breakpoint. This breakpoint was at a higher NAVA level than commonly used in this clinical situation. Immature neural feedback mechanisms warrant careful monitoring of preterm infants when supported with NIV-NAVA.Trial registration: clinicaltrials.gov NCT03780842. Date of registration December 12, 2018. What is Known:• Non-invasive neurally adjusted ventilatory assist (NIV-NAVA) is a safe, feasible and effective way to support respiration in preterm infants.• Intact neural feedback mechanisms are needed to protect the lung from overdistension in neurally adjusted ventilatory assist. What is New:• Preterm infants with acute RDS have a similar pattern of respiratory unloading as previously described.• Neural feedback mechanisms seem to be immature with the risk of insufficient support and lung injury due to overdistension of the lung.

Neurally adjusted ventilatory assist in preterm infants: A systematic review and meta‐analysis

“…Nevertheless, several clinical studies demonstrated that the point of optimal unloading, the breakpoint, could be found in preterm infants by titrating the NAVA level and monitoring changes in PIP and Edi. 23,24 This breakpoint could be used to set the ideal level of support for each infant. In only one of the included trials a titration procedure was used to set the NAVA level.…”

Is neurally adjusted ventilatory assist feasible and safe in the extremely preterm infant?

“…2 Results of the NIV-NAVA patients were published earlier. 5 Nine preterm infants with RDS on invasive NAVA underwent the titration procedure. Mean (SD) gestational age at birth was 28.6 (2, 4) weeks and mean (SD) birth weight was 1214 (761) grams.…”

“…As a consequence, a breakpoint can be observed where increasing NAVA levels no longer result in increasing peak inspiratory pressures, described as the point of optimal NAVA support 1,2 . Although several clinical studies have shown that NAVA can be used in preterm and even very preterm infants, uncertainty remains about the maturity and functioning of these neural feedback mechanisms in the most immature infants 3–5 . Also, in clinical practice, the use of NAVA in extremely preterm infants remains challenging.…”

“…After inclusion, patients underwent a titration procedure similar to what was done in previous studies on the same topic and as described in detail in the study protocol (http://clinicaltrials.gov NCT03780842) 2 . Results of the NIV‐NAVA patients were published earlier 5 …”

“…1,2 Although several clinical studies have shown that NAVA can be used in preterm and even very preterm infants, uncertainty remains about the maturity and functioning of these neural feedback mechanisms in the most immature infants. [3][4][5] Also, in clinical practice, the use of NAVA in extremely preterm infants remains challenging.…”