Clinical outcome in neurally adjusted ventilatory assist: a review

Background: Neurally adjusted ventilatory assist (NAVA) is a support mode of mechanical ventilation in which the ventilator is triggered by an electrical signal from the diaphragm (EAdi). Beneficial effects on physiological parameters are unequivocal. However, the effect of NAVA on clinical endpoints is unclear. The aim of this review was to assess the effect of NAVA on clinical endpoints. Methods: A systematic review was performed using PubMed. Inclusion criteria were: adult intensive care population, comparison between NAVA and other modes of ventilation and clinical outcome parameters or patient-related outcome measures (PROMs). Exclusion criteria were: animal studies, paediatric studies and language other than English, German or Dutch. Results: 538 articles were screened and six articles remained. Three used clinical outcome measures and three reported PROMs. No difference in mortality or other primary endpoints could be shown, but beneficial effects in secondary endpoints were seen. In one study positive effects of NAVA seemed to be more associated with measurement of EAdi than with NAVA mode itself. This effect might have biased the results of the other included studies. Regarding PROMs, no clinically relevant increase in comfort could be shown. One study revealed an increase in quality and quantity of sleep. Conclusions: Studies regarding clinical outcome with NAVA are sparse. No robust advantage of NAVA on primary endpoints was shown. The presented advantages were possibly attributed to asynchrony detection, instead of NAVA mode itself. Future research should aim to differentiate between recognition of asynchrony and the effects of NAVA mode itself.