Endeman, Rik

Gommers, Diederik

Somhorst, Peter

van der Zee, Philip

English

EUR Research Repository

20. Bhat TA, Kalathil SG, Bogner PN, Blount BC, Goniewicz ML, ThanavalaYM. An animal model of inhaled vitamin E acetate and EVALI-likelung injury. N Engl J Med 2020;382:1175–1177.Copyright © 2020 by the American Thoracic SocietyIn Patients with ARDS, Optimal PEEP Should Not BeDetermined Using the Intersection of Relative Collapseand Relative OverdistentionTo the Editor:With great interest, we read the article by van der Zee and colleaguessuggesting an individualized approach for setting the correctamount of positive end-expiratory pressure (PEEP) in ventilatedpatients with coronavirus disease (COVID-19) (1). In theircohort of 15 mechanically ventilated patients with COVID-19,they used electrical impedance tomography to study the relativeoverdistention and relative collapse curves. The authors state thatoptimal PEEP for these patients is at the intersection of thesecurves and close to the values suggested in the high PEEP/FIO2table. This intersection has indeed been used to set optimal PEEPbut only for mechanical ventilation during surgery (2).Using the intersection of relative collapse and relativeoverdistention suggests that both phenomena are equallyharmful for patients with acute respiratory distress syndrome.Unfortunately, there is no evidence in the literature that supportsthis assumption. In fact, several studies and reviews suggest theopposite: overdistention may be more harmful (3–5).We fully agree with the authors that an individualized approachfor mechanical ventilation for patients with COVID-19 (or any formof acute respiratory distress syndrome for that matter) is veryimportant. But instead of recruitment of the lung with high PEEP,prone positioning with lower PEEP levels could be considered toimprove oxygenation and to recruit parts of the lung. In 14 patientsadmitted to our ICU, we have shown that using more PEEP oftenleads to reduction in lung compliance and increase in dead spaceventilation, which suggests overdistention of alveoli (6).In conclusion, although atelectrauma decreases with higherlevels of PEEP, hyperinflation increases, which is potentially evenmore harmful. Therefore, using the intersection of the relativeoverdistention and relative collapse with electrical impedancetomography in patients with COVID-19 is not the technique todetermine optimal PEEP for the individual patient. What vander Zee and colleagues do very elegantly show us with theirresearch, however, is that there is always a tradeoff with higher levelsof PEEP. nAuthor disclosures are available with the text of this letter atwww.atsjournals.org.Maarten van den Berg, M.D.*Hans van der Hoeven, M.D., Ph.D.Radboud University Medical CentreNijmegen, the Netherlands*Corresponding author (e-mail: maarten.vandenberg@radboudumc.nl).References1. van der Zee P, Somhorst P, Endeman H, Gommers D. Electricalimpedance tomography for positive end-expiratory pressure titrationin COVID-19–related acute respiratory distress syndrome [letter]. Am JRespir Crit Care Med 2020;202:280–284.2. Pereira SM, Tucci MR, Morais CCA, Simões CM, Tonelotto BFF,Pompeo MS, et al. Individual positive end-expiratory pressuresettings optimize intraoperative mechanical ventilation andreduce postoperative atelectasis. Anesthesiology 2018;129:1070–1081.3. Bellani G, Guerra L, Musch G, Zanella A, Patroniti N, Mauri T, et al. Lungregional metabolic activity and gas volume changes induced by tidalventilation in patients with acute lung injury. Am J Respir Crit CareMed 2011;183:1193–1199.4. Gattinoni L, Quintel M, Marini JJ. Volutrauma and atelectrauma: which isworse? Crit Care 2018;22:264.5. Chiumello D, Carlesso E, Cadringher P, Caironi P, Valenza F, Polli F,et al. Lung stress and strain during mechanical ventilation for acuterespiratory distress syndrome. Am J Respir Crit Care Med 2008;178:346–355.6. Roesthuis L, van den Berg M, van der Hoeven H. Advanced respiratorymonitoring in COVID-19 patients: use less PEEP!Crit Care 2020;24:230.Copyright © 2020 by the American Thoracic SocietyReply to van den Berg and van der HoevenFrom the Authors:We thank van den Berg and van der Hoeven for the opportunity tofurther discuss our research letter in which positive end-expiratorypressure (PEEP) was titrated at the level of lowest relative alveolaroverdistention and collapse based on electrical impedancetomography (EIT) (1). In their comment, the authors argue thatPEEP should not be set at the minimum level of both alveolaroverdistention and collapse, as alveolar overdistention is potentiallymore harmful.This article is open access and distributed under the terms of the CreativeCommons Attribution Non-Commercial No Derivatives License 4.0 (http://creativecommons.org/licenses/by-nc-nd/4.0/). For commercial usage andreprints, please contact Diane Gern (dgern@thoracic.org).Originally Published in Press as DOI: 10.1164/rccm.202006-2175LE onAugust 5, 2020This article is open access and distributed under the terms of the CreativeCommons Attribution Non-Commercial No Derivatives License 4.0 (http://creativecommons.org/licenses/by-nc-nd/4.0/). For commercial usage andreprints, please contact Diane Gern (dgern@thoracic.org).Author Contributions: Conception of the work: P.v.d.Z., P.S., H.E., and D.G.Data acquisition and analysis: P.v.d.Z. and P.S. Drafting the manuscript:P.v.d.Z. Revising the manuscript: P.S., H.E., and D.G. Final approval of theversion: P.v.d.Z., P.S., H.E., and D.G. All authors had full access to all thedata and take responsibility for the integrity of the data and accuracy of dataanalysis.Originally Published in Press as DOI: 10.1164/rccm.202006-2460LE onAugust 5, 2020CORRESPONDENCECorrespondence 1189 We fully agree that alveolar overdistention is harmful toour patients. The Alveolar Recruitment Trial showed us thatsystematically performed recruitment maneuvers, known to causealveolar overdistention, increased mortality rate in patients with acuterespiratory distress syndrome (ARDS) (2). However, the amount ofalveolar overdistention or collapse prior to the application of highairway pressures was unknown. Determining alveolar overdistentionand collapse is crucial, as PEEP titration approaches are based on theassumption that there is an optimal compromise between alveolarrecruitment (i.e., limit the amount of collapse) and minimizingalveolar overdistention.Numerous bedside PEEP titration approaches have beendescribed, but none have shown to improve patient survival in largerandomized controlled trials. In addition, correlation betweendifferent approaches is poor. The explanation is that most bedsidePEEP titration approaches have at least one of the following threelimitations: 1) the approach does not quantify alveolar recruitment;2) the respiratory system is assessed as a whole, and local lunginhomogeneities remain undetected; and 3) alveolar overdistentionis not quantified.EIT is a functional imaging tool that continuously assessesregional ventilation and lung volume changes at the bedside. As such,EIT is a bedside PEEP titration approach that quantifies both alveolarrecruitment and alveolar overdistention and is able to detect local lunginhomogeneities. However, the amount of studies that used EIT totitrate PEEP in critically ill patients with ARDS is limited. In addition,there is no consensus on how to interpret EIT data.Blankman and colleagues (3) compared several EIT-derivedPEEP titration approaches in patients after cardiac surgery andproposed the intratidal gas distribution index to identifyalveolar overdistention in the nondependent lung regions and totitrate PEEP. In a case series, Yoshida and colleagues (4) used aventral-dorsal ventilation distribution of 50–50% to reachhomogeneous ventilation and limit alveolar overdistention. Incontrast, Franchineau and colleagues (5) aimed to limit the amount ofrelative collapse to 15% while maintaining the lowest percentage ofoverdistention in patients with extracorporeal membrane oxygenation.Alternatively, we could have aimed for the greatest amount ofventilated pixels or calculate the global inhomogeneity index. Wechose to titrate PEEP at the lowest level of relative alveolaroverdistention and collapse, as it is a simple and intuitive approachthat has proven to be beneficial in mechanically ventilated patientsduring surgery (6). This approach resulted in low driving pressuresand low transpulmonary pressures in all our patients.We share the concerns of van den Berg and van der Hoeven thatalveolar overdistention is harmful to the lungs. Therefore, wequantified the amount of alveolar overdistention before applyinghigher PEEP in our patients with coronavirus disease (COVID-19)–related ARDS. The Pleural Pressure Working Group’s plannedRECRUIT (Recruitment Assessed by Electrical ImpedanceTomography: Feasibility, Correlation with Clinical Outcomes andPilot Data on Personalised PEEP Selection) project (https://www.plugwgroup.org/), which aims to compare the resultsof different bedside methods to titrate PEEP based on EIT,might provide us with some answers on how to titrate PEEP usingEIT data. In the meantime, we agree with our colleagues to limit theamount of alveolar overdistention in patients with COVID-19–related ARDS by applying prone positioning and quantifying theamount of alveolar overdistention during a PEEP trial. nAuthor disclosures are available with the text of this letter atwww.atsjournals.org.Philip van der Zee, M.D.*Peter Somhorst, M.Sc.Henrik Endeman, M.D., Ph.D.Diederik Gommers, M.D., Ph.D.Erasmus Medical CenterRotterdam, the NetherlandsORCID ID: 0000-0002-5577-6848 (P.v.d.Z.).*Corresponding author (e-mail: p.vanderzee@erasmusmc.nl).References1. van der Zee P, Somhorst P, Endeman H, Gommers D. Electricalimpedance tomography for positive end-expiratory pressure titrationin COVID-19–related acute respiratory distress syndrome [letter]. Am JRespir Crit Care Med 2020;202:280–284.2. Writing Group for the Alveolar Recruitment for Acute Respiratory DistressSyndrome Trial (ART) Investigators; Cavalcanti AB, Suzumura EA,Laranjeira LN, Paisani DM, Damiani LP, Guimaraes HP, et al. Effect oflung recruitment and titrated positive end-expiratory pressure (PEEP) vslow PEEP on mortality in patients with acute respiratory distresssyndrome: a randomized clinical trial. JAMA 2017;318:1335–1345.3. Blankman P, Hasan D, Erik G, Gommers D. Detection of ‘best’ positiveend-expiratory pressure derived from electrical impedancetomography parameters during a decremental positive end-expiratorypressure trial. Crit Care 2014;18:R95.4. Yoshida T, Piraino T, Lima CAS, Kavanagh BP, Amato MBP,Brochard L. Regional ventilation displayed by electrical impedancetomography as an incentive to decrease positive end-expiratory pressure.Am J Respir Crit Care Med 2019;200:933–937.5. Franchineau G, Bréchot N, Lebreton G, Hekimian G, Nieszkowska A,Trouillet JL, et al. Bedside contribution of electrical impedancetomography to setting positive end-expiratory pressure for extracorporealmembrane oxygenation-treated patients with severe acute respiratorydistress syndrome. Am J Respir Crit Care Med 2017;196:447–457.6. Pereira SM, Tucci MR, Morais CCA, Simões CM, Tonelotto BFF,Pompeo MS, et al. Individual positive end-expiratory pressuresettings optimize intraoperative mechanical ventilation and reducepostoperative atelectasis. Anesthesiology 2018;129:1070–1081.Copyright © 2020 by the American Thoracic SocietyAn Expanded COVID-19 Telemedicine IntermediateCare Model Using Repurposed Hotel RoomsTo the Editor:We read with great interest the recent article fromBruni and colleagues (1) describing a hotel-based cohortThis article is open access and distributed under the terms of the CreativeCommons Attribution Non-Commercial No Derivatives License 4.0(http://creativecommons.org/licenses/by-nc-nd/4.0/). For commercial usageand reprints, please contact Diane Gern (dgern@thoracic.org).Author Contributions: All authors were involved in preparation and review ofthe content. In addition, all authors were involved in the planning of the caremodel described in the letter.Originally Published in Press as DOI: 10.1164/rccm.202007-2902LE onAugust 13, 2020CORRESPONDENCE1190 American Journal of Respiratory and Critical Care Medicine Volume 202 Number 8 | October 15 2020 

In Patients with ARDS, Optimal PEEP Should Not Be Determined Using the Intersection of Relative Collapse and Relative Overdistention Reply

https://pure.eur.nl/files/48382281/Repub_131468_O-A.pdf

In Patients with ARDS, Optimal PEEP Should Not Be Determined Using the Intersection of Relative Collapse and Relative Overdistention Reply

Abstract

Similar works

Full text

Available Versions

EUR Research Repository