Assessment of triggered ventilation - NAVA Versus ACV
Research type
Research Study
Full title
Randomised crossover studies of Neurally Adjusted Ventilator Assist (NAVA) versus assist control ventilation (ACV)
IRAS ID
188303
Contact name
Anne Greenough
Contact email
Sponsor organisation
King’s College Hospital NHS Foundation Trust
Duration of Study in the UK
1 years, 0 months, 0 days
Research summary
Despite improvements in survival rates of extremely preterm born infants, the incidence of bronchopulmonary dysplasia (BPD) remains unchanged over the last two decades. [1] As invasive ventilation is frequently necessary and indeed life saving, numerous ventilator strategies have been developed to reduce damage to the developing lung. Synchronisation of mechanical breaths with the patient’s respiratory effort offers the theoretical benefit of improving oxygenation and ventilation, requiring lower ventilator pressures, fewer air leaks and increased patient comfort with less sedation requirements.
A Cochrane review compared methods of improving synchronisation using patient triggered ventilation [either assist control ventilation (ACV) or synchronous intermittent mandatory ventilation (SIMV)] with conventional ventilation (CMV). [2] The meta-analysis demonstrated that ACV and SIMV were associated with a shorter duration of ventilation compared to CMV, but there was no significant reduction in BPD.
During ACV and SIMV, triggering is via either pressure or flow sensors which determine the initiation of inflation. In the neonatal population, with small tidal volumes, high respiratory rates and often-significant leak from uncuffed endotracheal tubes, sensitive triggering can be challenging and hence, some of the benefits of triggered ventilation may not materialise.
Neurally adjusted ventilatory assist (NAVA) utilises the electrical activity of the diaphragm to trigger the ventilator. A modified nasogastric feeding tube with a series of electrodes allows monitoring of the diaphragmatic electromyogram (Edi). The waveform of the Edi is used to trigger and control ventilator support. This technique has been successfully used in very low birth weight infants weighing as little as 640g. [3]
NAVA, however, has not been assessed in infants with evolving/established BPD, hence our study is to assess whether it has any advantages over ACV.
References
1. Costeloe K L, Hennessy E M, Haider S, Stacey F, Marlow N, Draper E S. Short term outcomes after extreme preterm birth in England: comparison of two birth cohorts in 1995 and 2006 (the EPICure studies). BMJ 2012;345:e7976.
2. Greenough A, Dimitriou G, Prendergast M, Milner A D. Synchronized mechanical ventilation for respiratory support in newborn infants. Cochrane Database of Systematic Reviews 2008:CD000456.
3. Beck J, Reilly M, Grasselli G, Mirabella L, Slutsky A S, Dunn M S, et al. Patient-ventilator interaction during neurally adjusted ventilatory assist in low birth weight infants. Pediatr Res 2009;65:663-8.REC name
West Midlands - Solihull Research Ethics Committee
REC reference
15/WM/0330
Date of REC Opinion
30 Sep 2015
REC opinion
Further Information Favourable Opinion