RT Journal Article SR Electronic T1 Patient–ventilator interaction during noninvasive ventilation: practical assessment and theoretical basis JF Breathe JO breathe FD European Respiratory Society SP 322 OP 333 DO 10.1183/18106838.0504.322 VO 5 IS 4 A1 S. Nava A1 A. Carlucci A1 P. Ceriana YR 2009 UL http://breathe.ersjournals.com/content/5/4/322.abstract AB Summary Synchrony refers to the agreement between the patient's own (neural) and the ventilator's (mechanical) inspiratory and expiratory time. Noninvasive ventilation (NIV) is a semi-open system, which means air leaks are common. This greatly affects patient synchrony. In addition to air leaks, there are other factors that affect patient–ventilator mismatching. This review will focus on NIV and on the main forms of asynchrony and mismatching, their causes and methods to eventually identify these problems from the flow and pressure signals.