TY - JOUR T1 - Non-Interventional Monitoring of Expiratory Flow Limitation during Experimental Mechanical Ventilation JF - ERJ Open Research JO - erjor DO - 10.1183/23120541.00264-2020 SP - 00264-2020 AU - Giorgos Marinakis AU - Michael Paraschos AU - Maria Patrani AU - Theodoros Tsoutsouras AU - Miltos Vassiliou Y1 - 2020/01/01 UR - http://openres.ersjournals.com/content/early/2020/10/01/23120541.00264-2020.abstract N2 - Background Εxpiratory flow limitation (EFL) is common among ICU patients under mechanical ventilation (MV) and may have significant clinical consequences. In the present study, we examine the possibility of non-interventional detection of EFL during experimental MV.Methods Eight artificially ventilated New Zealand rabbits were included in the experiments. EFL was induced during MV by application of negative expiratory pressure (−5, −8 and −10 hPa) and detected by the negative expiratory pressure (NEP) technique. Airway pressure (Paw) and flow (Vʹ) were digitally recorded and processed off-line for the evaluation of respiratory mechanics. The method is based on the computation and monitoring of instantaneous respiratory resistance Rrs(t). The resistive pressure (Paw,res(t)) is calculated by subtracting from Paw its elastic component and the end expiratory pressure (EEP), as assessed by linear regression. Then, Rrs(t) is computed as the instant ratio Paw,res(t)/Vʹ(t).Results Two completely different patterns of expiratory Rrs(t) separate the cases with EFL from those without EFL. Small and random fluctuations are noticed when EFL is absent, whereas the onset of EFL is accompanied by an abrupt and continuous rise in Rrs(t), towards the end of expiration. Thus, EFL is not only detected but may also be quantified from the volume still to be expired at the time EFL occurs.Conclusion The proposed technique is a simple, accurate and non-interventional tool for the EFL monitoring during MV.FootnotesThis manuscript has recently been accepted for publication in the ERJ Open Research. It is published here in its accepted form prior to copyediting and typesetting by our production team. After these production processes are complete and the authors have approved the resulting proofs, the article will move to the latest issue of the ERJOR online. Please open or download the PDF to view this article.Conflict of interest: Dr. Marinakis has nothing to disclose.Conflict of interest: Dr. Paraschos has nothing to disclose.Conflict of interest: Dr. Patrani has nothing to disclose.Conflict of interest: Dr. Tsoutsouras has nothing to disclose.Conflict of interest: Dr. Vassiliou has nothing to disclose. ER -