Skip to main content

The ARDSnet protocol may be detrimental in COVID-19

To the Editor,

Intensive care units are overwhelmed with COVID-19 ARDS patients during the last months, and increased mortality has been reported [1]. The Surviving Sepsis Campaign-COVID-19 guidelines and, recently, the American Thoracic Society (ATS) proposed to treat COVID-19 per ARDSnet protocol [2, 3]. However, there are a few issues we would like to address concerning the ventilatory strategy and fluid administration. Heart-lung interactions may play a crucial role, especially in the management of COVID-19 patients.

In the largest series of almost 1600 COVID-19 ICU patients, the median PaO2/FiO2 was 160 and the median PEEP used was 14 cmH2O [1]. It seems that PEEP was set according to predefined criteria (ARDSnet, SSC-COVID-19 guidelines, ATS statement) [2, 3]. However, COVID-19 ARDS does not seem to be “typical” [4]. In patients from our unit, the median static compliance was 52 ml/cmH2O, and this seems to be the case in most intubated patients in Greece (compliance of 50–65 ml/cmH2O, anecdotal reports) and other countries [4]. Ιn our patients, the mean PaO2/FiO2 value was 89. If we had followed the suggested protocols, we should have applied a PEEP of 18 cmH2O. Contrary, a median PEEP of 8 cmH2O was the “best” PEEP, evaluated combining respiratory variables (compliance, FRC, PaCO2) and hemodynamics through echocardiography (RV function, SPAP through tricuspid regurgitation). Trials of increased PEEP worsened hemodynamics and increased vasopressors. In most cases, fluid administration was decided considering inferior vena cava distensibility index and pulse pressure variation (tidal volume set at 8 ml/kg).

It is well-known that when lung compliance is relatively normal, even more than 50% of the alveolar pressure is transmitted to the pleural pressure. Relatively high PEEP (in a non-recruitable lung) may have a detrimental impact on hemodynamics, deteriorating venous return. Moreover, application of high PEEP when not-needed unnecessarily increases transpulmonary pressure forcing West’s zone 3 lung regions to zones 2 and 1, leading to dead space ventilation and increasing pulmonary vascular resistance [5]. Both effects are exacerbated in hypovolemic patients. Therefore, fluid restriction may not be so applicable in SARS-COV-2 ARDS. Hypovolemia and hemodynamic compromise in hypertensive patients might contribute to the observed increased mortality in those patients receiving diuretics as standard treatment, as hemodynamic instability leads to organ hypoperfusion and ultimately fatal multiorgan failure [1].

It seems that in most SARS-CoV-2 patients, we have to abandon the ARDSnet protocol (high-PEEP, low-Vt). Point-of-care echocardiography may guide decisions.

Availability of data and materials

Not applicable


  1. Grasseli G, Zangrillo A, Zanella A, Antonelli M, Cabrini L, Castelli A, et al. Baseline charecteristics and outcomes of 1591 patients infected with SARS-CoV-2 admitted to ICUs of the Lombardy Region, Italy. JAMA 2020 doi:

  2. Alhazzani W, Møller M, Arabi Y, Loeb M, Gong MN, Fan E, et al. Surviving Sepsis Campaign: guidelines on the management of critically ill. Intensive Care Med Mar. 2020;28:1–34.

    Article  CAS  Google Scholar 

  3. Jamil S, Mark N, Carlos G, Dela Cruz C, Gross J, Pasnick S. Diagnosis and management of COVID-19 disease. AJRCCM. 2020.

  4. Gattinoni L, Coppola S, Cressoni M, Busana M, Rossi S, Chiumello D. COVID-19 does not lead to a “typical” acute respiratory distress syndrome. Am J Resp Crit Care Med. 2020.

  5. Gattinoni L, Chiumello D, Rossi S. COVID-19 pneumonia: ARDS or not? Crit Care. 2020;24:154.

    Article  PubMed  PubMed Central  Google Scholar 

Download references





Author information

Authors and Affiliations



The authors equally contributed to the concept of the manuscript based on observations on the management of COVID-19 mechanically ventilated ARDS patients. The author(s) read and approved the final manuscript.

Corresponding author

Correspondence to Vasiliki Tsolaki.

Ethics declarations

Ethics approval and consent to participate

Not applicable

Consent for publication

Not applicable

Competing interests

Not applicable

Additional information

Publisher’s Note

Springer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations.

Rights and permissions

Open Access This article is licensed under a Creative Commons Attribution 4.0 International License, which permits use, sharing, adaptation, distribution and reproduction in any medium or format, as long as you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons licence, and indicate if changes were made. The images or other third party material in this article are included in the article's Creative Commons licence, unless indicated otherwise in a credit line to the material. If material is not included in the article's Creative Commons licence and your intended use is not permitted by statutory regulation or exceeds the permitted use, you will need to obtain permission directly from the copyright holder. To view a copy of this licence, visit The Creative Commons Public Domain Dedication waiver ( applies to the data made available in this article, unless otherwise stated in a credit line to the data.

Reprints and permissions

About this article

Check for updates. Verify currency and authenticity via CrossMark

Cite this article

Tsolaki, V., Zakynthinos, G.E. & Makris, D. The ARDSnet protocol may be detrimental in COVID-19. Crit Care 24, 351 (2020).

Download citation

  • Received:

  • Accepted:

  • Published:

  • DOI: