TY - JOUR T1 - Decreased breathing variability is associated with poorer outcome in mechanically ventilated patients JF - ERJ Open Research JO - erjor DO - 10.1183/23120541.00544-2022 SP - 00544-2022 AU - Camille Rolland-Debord AU - Tymothee Poitou AU - Come Bureau AU - Isabelle Rivals AU - Thomas Similowski AU - Alexandre Demoule Y1 - 2023/01/01 UR - http://openres.ersjournals.com/content/early/2023/02/16/23120541.00544-2022.abstract N2 - Rationale: Breathing is a cyclic activity that is by nature variable. Breathing variability is modified in mechanically ventilated (MV) patients.Objectives: We aimed to evaluate whether decreased variability on the day of transition from assist-control ventilation to a partial mode of assistance was associated with a poorer outcome.Methods: This was an ancillary study of a multicenter, randomized, controlled trial comparing neurally adjusted ventilatory assist to pressure support ventilation. Flow and the electrical activity of the diaphragm (EAdi) were recorded within 48 h of switching from controlled ventilation to a partial mode of ventilatory assistance.Measurements: Variability of flow and EAdi-related variables were quantified by the coefficient of variation, the amplitude ratio of the spectrum's first harmonic to its zero-frequency component (H1/DC) and two surrogates of complexity,.Main Results: Ninety-eight patients ventilated for a median duration of 5 days were included. H1/DC of inspiratory flow and EAdi were lower in survivors than in non-survivors, suggesting a higher breathing variability in this population (for flow, 37% versus 45%, p=0.041; for EAdi, 42% versus 52%, p=0.002). By multivariate analysis, H1/DC of inspiratory EAdi was independently associated with day-28 mortality (odds ratio 1.10, p=0.002). H1/DC of inspiratory EAdi was lower in patients with a duration of MV<8 days (41% versus 45%, p=0.022). Noise limit and the largest Lyapunov exponent suggested a lower complexity in patients with a duration of MV<8 days.Conclusion: Higher breathing variability and lower complexity are associated with higher survival and lower duration of 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: Alexandre Demoule reports grants or contracts from Philips, Fisher & Paykel, French Ministry of Health, Respinor, and Lungpacer, outside the submitted work; consulting fees from Lungpacer, and Respinor, outside the submitted work; payment or honoraria from Fisher & Paykel, Getinge, Lungpacer, Gilead, Lowenstein, and Astra, outside the submitted work; support for attending meetings and/or travel from Lungpacer, outside the submitted work.Conflict of interest: Thomas Similowski reports grants or contracts from Chiesi France, and Air Liquide Medical Systems, outside the submitted work; consulting fees from AstraZeneca France, Boerhinger Ingelheim France, Novartis France, TEVA France, Chiesi France, Lungpacer Inc., and ADEP Assistance, outside the submitted work; payment or honoraria from AstraZeneca France, Boerhinger Ingelheim France, Novartis France, TEVA France, Chiesi France, Lungpacer Inc., and ADEP Assistance, outside the submitted work.Conflict of interest: The remaining authors have nothing to disclose. ER -