Near real-time observation reveals increased prevalence of young patients in the ICU during the emerging third SARS-CoV-2 wave in Switzerland

Matthias Peter Hilty, André Moser, Sascha David, Pedro David Wendel Garcia, Giuliana Capaldo, Stefanie Keiser, Thierry Fumeaux, Philippe Guerci, Jonathan Montomoli, Thomas P. Van Boeckel, Marie Madlen Jeitziner, Yok Ai Que, Stefan Jakob, Reto Andreas Schüpbach, Investigators For Switzerland Risc-Icu Investigators For Switzerland

Research output: Contribution to journalComment/Letter to the editorPopular

3 Citations (Scopus)


AIMS OF THE STUDY: During the ongoing COVID-19 pandemic, the launch of a large-scale vaccination campaign and virus mutations have hinted at possible changes in transmissibility and the virulence affecting disease progression up to critical illness, and carry potential for future vaccination failure. To monitor disease development over time with respect to critically ill COVID-19 patients, we report near real-time prospective observational data from the RISC-19-ICU registry that indicate changed characteristics of critically ill patients admitted to Swiss intensive care units (ICUs) at the onset of a third pandemic wave. METHODS: 1829 of 3344 critically ill COVID-19 patients enrolled in the international RISC-19-ICU registry as of 31 May 2021 were treated in Switzerland and were included in the present study. Of these, 1690 patients were admitted to the ICU before 1 February 2021 and were compared with 139 patients admitted during the emerging third pandemic wave RESULTS: Third wave patients were a mean of 5.2 years (95% confidence interval [CI] 3.2-7.1) younger (median 66.0 years, interquartile range [IQR] 57.0-73.0 vs 62.0 years, IQR 54.5-68.0; p <0.0001) and had a higher body mass index than patients admitted in the previous pandemic period. They presented with lower SAPS II and APACHE II scores, less need for circulatory support and lower white blood cell counts at ICU admission. P/F ratio was similar, but a 14% increase in ventilatory ratio was observed over time (p = 0.03) CONCLUSION: Near real-time registry data show that the latest COVID-19 patients admitted to ICUs in Switzerland at the onset of the third wave were on average 5 years younger, had a higher body mass index, and presented with lower physiological risk scores but a trend towards more severe lung failure. These differences may primarily be related to the ongoing nationwide vaccination campaign, but the possibility that changes in virus-host interactions may be a co-factor in the age shift and change in disease characteristics is cause for concern, and should be taken into account in the public health and vaccination strategy during the ongoing pandemic.

Original languageEnglish
Article numberw20553
Pages (from-to)w20553
JournalSwiss Medical Weekly
Issue number29-30
Publication statusPublished - 19 Jul 2021

Bibliographical note

Funding Information:
This work is funded and endorsed by the Swiss Society of Intensive Care Medicine and unrestricted research grants by the Institute of Intensive Care Medicine at the University Hospital of Zurich and Cy-toSorbents Europe GmbH, Berlin, Germany. The funders had no role in the design and conduct of the study; collection, management, analysis, and interpretation of the data; preparation, review, or approval of the manuscript; and decision to submit the manuscript for publication.

Publisher Copyright:
© 2021 EMH Swiss Medical Publishers Ltd.. All rights reserved.


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