Neural pressure support ventilation as a novel strategy to improve patient–ventilator synchrony in adult respiratory distress syndrome

Editor—Several assisted ventilatory modes are available for invasive mechanical ventilation. Pressure support ventilation (PSV) is one of the most frequently used, 1 Yoshida T. Fujino Y. Amato M.B.P. Kavanagh B.P. Fifty years of research in ARDS. Spontaneous breathing during mechanical ventilation. Risks, mechanisms, and management. Am J Respir Crit Care Med. 2017; 195: 985-992 Crossref PubMed Scopus (202) Google Scholar in which inspiration is triggered by a pneumatic signal (i.e. flow or pressure), 2 Mauri T. Bellani G. Grasselli G. et al. Patient-ventilator interaction in ARDS patients with extremely low compliance undergoing ECMO: a novel approach based on diaphragm electrical activity. Intensive Care Med. 2013; 39: 282-291 Crossref PubMed Scopus (81) Google Scholar while expiration is cycled when the inspiratory flow decreases to a predetermined fraction of peak inspiratory flow. 3 MacIntyre N.R. Clinically available new strategies for mechanical ventilatory support. Chest. 1993; 104: 560-565 Abstract Full Text Full Text PDF PubMed Scopus (26) Google Scholar Neurally adjusted ventilatory assist (NAVA) ventilation is a partial ventilatory mode using a specialised nasogastric probe that measures diaphragmatic electrical activity, which in turn is used to trigger inspiration, cycle expiration, and provide proportional ventilatory assistance. 4 Kacmarek R.M. Proportional assist ventilation and neurally adjusted ventilatory assist. Respir Care. 2011; 56: 140-152 Crossref PubMed Scopus (67) Google Scholar NAVA is particularly efficient in patients with triggering issues such as late acute respiratory distress syndrome (ARDS) with low respiratory system compliance. 2 Mauri T. Bellani G. Grasselli G. et al. Patient-ventilator interaction in ARDS patients with extremely low compliance undergoing ECMO: a novel approach based on diaphragm electrical activity. Intensive Care Med. 2013; 39: 282-291 Crossref PubMed Scopus (81) Google Scholar However, despite its theoretical benefits, setting up NAVA is not straightforward, given that the ventilator's level of assistance is not immediately interpretable. 5 Grasselli G. Castagna L. Abbruzzese C. et al. Assessment of airway driving pressure and respiratory system mechanics during neurally adjusted ventilatory assist. Am J Respir Crit Care Med. 2019; 200: 785-788 Crossref PubMed Scopus (8) Google Scholar Neural pressure support (NPS) is an innovative ventilatory mode during which diaphragmatic electrical activity triggers inspiration and expiration as in NAVA, but a constant assistance level chosen by the operator is delivered. We present a case illustrating patient–ventilator interactions under PSV, NAVA, and NPS in a patient with low respiratory system compliance ARDS.