Neurally Adjusted Ventilatory Assist in Acute Respiratory Failure-A Narrative Review

Maintaining spontaneous breathing has both potentially beneficial and deleterious consequences in patients with acute respiratory failure, depending on the balance that can be obtained between the protecting and damaging effects on the lungs and the diaphragm. Neurally adjusted ventilatory assist (NAVA) is an assist mode, which supplies the respiratory system with a pressure proportional to the integral of the electrical activity of the diaphragm. This proportional mode of ventilation has the theoretical potential to deliver lung- and respiratory-muscle-protective ventilation by preserving the physiologic defense mechanisms against both lung overdistention and ventilator overassistance, as well as reducing the incidence of diaphragm disuse atrophy while maintaining patient-ventilator synchrony. This narrative review presents an overview of NAVA technology, its basic principles, the different methods to set the assist level and the findings of experimental and clinical studies which focused on lung and diaphragm protection, machine-patient interaction and preservation of breathing pattern variability. A summary of the findings of the available clinical trials which investigate the use of NAVA in acute respiratory failure will also be presented and discussed.

Automated summary

Maintaining spontaneous breathing in patients with acute respiratory failure can have both positive and negative effects on the lungs and diaphragm. Neurally adjusted ventilatory assist (NAVA) is an assist mode that provides proportional pressure to the respiratory system based on diaphragm activity. This ventilation mode has the potential to protect the lungs and respiratory muscles, reduce diaphragm disuse atrophy, and maintain patient-ventilator synchrony. This review summarizes the principles of NAVA technology, methods for setting the assist level, and findings from studies focused on lung and diaphragm protection, machine-patient interaction, and preservation of breathing pattern variability. The review also discusses the findings of clinical trials investigating the use of NAVA in acute respiratory failure.