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

To compare the effects of neurally adjusted ventilatory assist (NAVA) with other forms of synchronized artificial ventilation in preterm infants. A systematic review of randomized and quasi-randomized controlled trials with individual group allocation, both parallel-group trials as well as crossover trials, that included preterm infants born at less than 37 weeks gestational age and compared NAVA with any other form of synchronized mechanical ventilation with or without volume guarantee. Primary outcomes were death or bronchopulmonary dysplasia (BPD) at 36 weeks, total duration of respiratory support and neurodevelopmental outcome at 2 years. Secondary outcomes consisted of important procedural and clinical outcomes. Seven studies with a total of 191 infants were included, five randomized crossover trials and two parallel group randomized trials. No significant difference in the primary outcome of death or BPD (RR: 1.08, 95% CI: 0.33-3.55) was found. Peak inspiratory pressures were significantly lower with NAVA than with other forms of ventilation (MD -1.83 cmH2O [95% CI: -2.95 to -0.71]). No difference in any other clinical or ventilatory outcome was detected. Although associated with lower peak inspiratory pressures, the use of NAVA does not result in a reduced risk of death or BPD as compared to other forms of synchronized ventilation in preterm infants. However, the certainty of evidence is low due to imprecision of the effect estimate. Larger studies are needed to detect possible short- and long-term differences between ventilation modes.

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

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 cmH2O/µV and with increments of 0.5 cmH2O/µV every 3 min, up to a maximum level of 4.0 cmH2O/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) cmH2O/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.

Weaning strategies for the withdrawal of non-invasive respiratory support applying continuous positive airway pressure in preterm infants: a systematic review and meta-analysis.

BACKGROUND: The optimal method to wean preterm infants from non-invasive respiratory support (NIVRS) with nasal continuous positive airway pressure (CPAP) or high-flow nasal cannula is still unclear, and methods used vary considerably between neonatal units. OBJECTIVE: Perform a systematic review and meta-analysis to determine the most effective strategy for weaning preterm infants born before 37 weeks' gestation from NIVRS. METHOD: EMBASE, MEDLINE, CINAHL, Google and Cochrane Central Register of Controlled Trials were searched for randomised controlled trials comparing different weaning strategies of NIVRS in infants born before 37 weeks' gestation. RESULTS: Fifteen trials (1.547 infants) were included. With gradual pressure wean, the relative risk of successful weaning at the first attempt was 1.30 (95% CI 0.93 to 1.83), as compared with sudden discontinuation. Infants were weaned at a later postmenstrual age (PMA) (median difference (MD) 0.93 weeks (95% CI 0.19 to 1.67)). A stepdown strategy to nasal cannula resulted in an almost 3-week reduction in the PMA at successful weaning (MD -2.70 (95% CI -3.87 to -1.52)) but was associated with a significantly longer duration of oxygen supplementation (MD 7.80 days (95% CI 5.31 to 10.28)). A strategy using interval training had no clinical benefits. None of the strategies had any effect on the risk of chronic lung disease or the duration of hospital stay. CONCLUSION: A strategy of gradual weaning of airway pressure might increase the chances of successful weaning. Stepdown strategy from CPAP to nasal cannula is a useful alternative resulting in an earlier weaning, but the focus should remain on continued weaning in order to avoid prolonged oxygen supplementation. Interval training should probably not be used.