Skip to main content
  • Letter to the Editor
  • Open access
  • Published:

Intensive care unit-to-unit capacity transfers are associated with increased mortality: no hasty conclusions in the event of a crisis

A Letter to the Editor to this article was published on 09 July 2022

A Letter to the Editor to this article was published on 09 July 2022

The Original Article was published on 04 April 2022

Dear Editor,

We read with great interest the study of Parenmark et al., a large retrospective study, including 15,588 ICU-to-ICU interhospital transfers in Sweden over a 2-year period [1].

The authors describe three types of interhospital transfers: clinical transfer (need for specialised care not available in the admitting hospital), capacity transfer (making room for patients with more urgent need for intensive care when all ICU beds are occupied) and repatriation (return to the home ICU following initial treatment at another unit) the last one being labelled as reference. Their main result indicates an increase mortality within 30 days following discharge from the referring ICU in the subgroups of clinical and capacity transfers, with adjusted odds ratio of 1.17 (95% CI 1.02–1.36) and 1.25 (95% CI 1.06–1.49), respectively.

As the authors notice, the main result is somewhat surprising as higher mortality has not been reported in recent literature [2, 3]. Reasons could be explained as follow: first, the authors specify that 20% of capacity transfers occurred at night, involving severe critically ill patients with acute lung injury, sepsis, and cardiogenic shock. In light of these results, one could wonder whether it is safe or not for the patient to undergo a night ICU-to-ICU transfer compared to withholding the interhospital transport for a few hours until the sun rises, since night-shift patient’s discharge has been associated with a higher mortality [4].

Second, the authors pointed out that Sweden has a low number of ICU bed which could play a role in the higher mortality rate found following interhospital capacity and clinical transfers [5].

Solutions to tackle this higher mortality related to interhospital transfer would be to build up local resources for critical care: increasing ICU beds, recruiting ICU highly trained staff and Intensivist doctors to avoid transfers of critically ill patients at nights with severe unstable pathologies (especially during wintertime when respiratory sepsis and acute respiratory distress occur more frequently [6]).

Furthermore, the authors’ message must be balanced when facing crisis, such as the COVID-19 pandemic. Assuming that interhospital transfers are unsafe and choosing a strategy of implementation of new ICU beds to face surge of critically ill patients could lead to a higher mortality [7]. During the first months of the COVID-19 crisis, countries planned and organized large-scale interhospital transfers either for clinical or capacity reasons and demonstrated that transferred patients did not have a higher mortality rate [2, 3, 8]. However, we agree with the authors and acknowledge that “understanding the impact of ICU-to-ICU transfer on patient outcome is complex and must consider a couple of important aspects” such as identifying appropriate control patients.

Finally, as mentioned by the authors, robust prospective studies including before departure, ongoing transport and arrival data are needed to determine the timing of the transfer, the safest medical condition allowing for transfer, and whether transport impacts ICU mortality.

Availability of data and materials

Not applicable.



Intensive care unit


  1. Parenmark F, Walther SM. Intensive care unit to unit capacity transfers are associated with increased mortality: an observational cohort study on patient transfers in the swedish intensive care register. Ann Intensive Care. 2022;12:31.

    Article  Google Scholar 

  2. Sanchez M-A, Vuagnat A, Grimaud O, Leray E, Philippe J-M, Lescure F-X, et al. Impact of ICU transfers on the mortality rate of patients with COVID-19: insights from comprehensive national database in France. Ann Intensive Care. 2021;11:151.

    Article  Google Scholar 

  3. Chen E, Longcoy J, McGowan SK, Lange-Maia BS, Avery EF, Lynch EB, et al. interhospital transfer outcomes for critically Ill patients with coronavirus disease 2019 requiring mechanical ventilation. Crit Care Explor. 2021;3: e0559.

    Article  Google Scholar 

  4. Duke GJ, Green JV, Briedis JH. Night-shift discharge from intensive care unit increases the mortality-risk of ICU survivors. Anaesth Intensive Care. 2004;32:697–701.

    Article  CAS  Google Scholar 

  5. Bauer J, Brüggmann D, Klingelhöfer D, Maier W, Schwettmann L, Weiss DJ, et al. Access to intensive care in 14 european countries: a spatial analysis of intensive care need and capacity in the light of COVID-19. Intensive Care Med. 2020;46:2026–34.

    Article  CAS  Google Scholar 

  6. Danai PA, Sinha S, Moss M, Haber MJ, Martin GS. Seasonal variation in the epidemiology of sepsis. Crit Care Med. 2007;35:410–5.

    Article  Google Scholar 

  7. Taccone FS, Vangoethem N, Depauw R, Wittebole X, Blot K, Vanoyen H, et al. The role of organizational characteristics on the outcome of COVID-19 patients admitted to the ICU in Belgium. Lancet Reg Health Europe. 2020;2:100019.

    Article  Google Scholar 

  8. Painvin B, Messet H, Rodriguez M, Lebouvier T, Chatellier D, Soulat L, et al. Inter-hospital transport of critically ill patients to manage the intensive care unit surge during the COVID-19 pandemic in France. Ann Intensive Care. 2021;11:54.

    Article  CAS  Google Scholar 

Download references




This study did not receive any funding.

Author information

Authors and Affiliations



BP and JMT conceived the letter; BP wrote the manuscript and SE, AWT and JMT revised it. The authors read and approved the final manuscript.

Corresponding authors

Correspondence to Benoit Painvin or Jean-Marc Tadié.

Ethics declarations

Ethics approval and consent to participate

Not applicable.

Consent for publication

Not applicable.

Competing interests

The authors declare that they have no competing interests.

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

Reprints and permissions

About this article

Check for updates. Verify currency and authenticity via CrossMark

Cite this article

Painvin, B., Ehrmann, S., Thille, A.W. et al. Intensive care unit-to-unit capacity transfers are associated with increased mortality: no hasty conclusions in the event of a crisis. Ann. Intensive Care 12, 60 (2022).

Download citation

  • Received:

  • Accepted:

  • Published:

  • DOI: