Skip to main content
  • Matters Arising
  • Open access
  • Published:

ECMO in resuscitated drowning patients: a propensity score matched sub-analysis—a response to Jouffroy et al.

The Original Article was published on 25 August 2023

The Original Article was published on 20 July 2023

To the Editor,

We express our gratitude to Romain Jouffroy and Benoît Vivien for their valuable commentary on our manuscript titled "Results from 237 extracorporeal membrane oxygenation runs with drowned patients: a nationwide retrospective study" [1, 2]. These colleagues suggest an analysis of drowned patients managed solely by cardiopulmonary resuscitation (CPR) alone versus those with the combination of CPR and extracorporeal membrane oxygenation (ECMO). Needless to say, that this approach can be an important and insightful sub-analysis of our data set.

The primary objective of our manuscript was to examine the variance among all hospitalized drowning cases, focusing on the comparison of outcomes between those treated with ECMO and those without. Pursuant to this objective, and in light of the sub-analysis proposed by Jouffroy et al., we examined all patients subjected to in-hospital (OPS 8–77*) and out-of-hospital (ICD U69.13!) CPR following drowning events between 2018 and 2020. Due to a change in coding for in-hospital resuscitation and out-of-hospital resuscitation, this short timeframe had to be selected. Using propensity score matching based on age and Elixhauser Score, each patient of the ECMO group was matched with a patient of the non-ECMO group with similar characteristics (Table 1), hence of 122 drowned patients 50% (n = 61) received CPR only and 50% (61) received CPR and ECMO [3]. Mortality was 86.9% (n = 53) for the ECMO group and 55.7% (n = 34) for the non-ECMO group. Logistic regression analysis showed a significant association of increased hospital mortality with V-A ECMO (OR 22.907, CI: 3.652–143.695) and a protective effect for hypertension (OR 0.086, CI: 0.013–0.59) (Fig. 1). Notably, this sub-analysis demonstrated a significantly elevated mortality in the ECMO group compared to the non-ECMO patients. Both groups, after propensity score matching, showed no significant difference in disease severity, measured via the Elixhauser Score (ECMO n = 13, IQR: 8–19; Non-ECMO n = 11, IQR: 5–20; p = 0.66). The potential differences that could have been revealed by clinically established scores, such as SOFA or SAPS II, remain a limitation of our data set [4, 5].

Table 1 Patient characteristics for resuscitated drowned patients
Fig. 1
figure 1

Odds ratio for resuscitated drowned patients with mortality as outcome. V-V: venovenous; V-A: venoarterial; ECMO: extracorporeal membrane oxygenation; CPR: cardiopulmonary resuscitation

To address another important point made by Jouffroy et al. regarding the use of out-of-hospital cardiac arrest (OHCA) predictors, we acknowledge that the database's constraints limit further analysis [2, 6]. It is indeed surprising, both clinically and in the context of the literature, how a better survival with a stroke is associated in drowned patients. Smaller sample size may contribute, and outcomes might be a product of the sample at hand, potentially reversing in other scenarios and relying on secondary data can introduce inherent biases. Strokes might be under-diagnosed in non-survivors due to early fatalities, whereas survivors receive more comprehensive diagnostics. However, our sub-analysis of resuscitated drowned patients did not reproduce this finding.

Regarding the comment about potential censors in the multivariate logistic regression, such as chronic pulmonary disease, it is imperative to clarify that our logistic model, which was processed on the servers of the Federal Statistical Office, contained uncensored data. The censorship of our published results is solely for privacy and data protection reasons, and therefore, a censored value may be 1 or 2.

In conclusion, our sub-analysis vividly illustrates an extremely high mortality rate of more than 86% for resuscitated patients on ECMO, with a significantly increased in-hospital mortality associated with V-A ECMO. As previously emphasized, further studies are urgently required to evaluate the tangible benefits of ECMO therapy for resuscitated drowning victims.

Availability of data and materials

The Federal Statistical Office of Germany provided all data used. According to §21KHEntgG, reimbursement data are free for scientific use, but its availability is restricted and not publicly available. Upon reasonable request and with permission of the Federal Statistical Office of Germany, data are available from the authors.

References

  1. Jasny T, Kloka J, Old O, et al. Results from 237 extracorporeal membrane oxygenation runs with drowned patients: a nationwide retrospective study. Crit Care. 2023;27(1):293. https://doi.org/10.1186/s13054-023-04580-w.

    Article  PubMed  PubMed Central  Google Scholar 

  2. Jouffroy R, Vivien B. Comment on: Results from 237 extracorporeal membrane oxygenation runs with drowned patients. Crit Care. 2023;27(1):326. https://doi.org/10.1186/s13054-023-04624-1.

    Article  PubMed  PubMed Central  Google Scholar 

  3. van Walraven C, Austin PC, Jennings A, Quan H, Forster AJ. A modification of the Elixhauser comorbidity measures into a point system for hospital death using administrative data. Med Care. 2009;47(6):626–33. https://doi.org/10.1097/MLR.0b013e31819432e5.

    Article  PubMed  Google Scholar 

  4. Le Gall JR, Lemeshow S, Saulnier F. A new simplified acute physiology score (SAPS II) based on a European/North American multicenter study. JAMA. 1993;270(24):2957–63. https://doi.org/10.1001/jama.270.24.2957.

    Article  PubMed  Google Scholar 

  5. Vincent JL, Moreno R, Takala J, et al. The SOFA (Sepsis-related Organ Failure Assessment) score to describe organ dysfunction/failure. On behalf of the working group on sepsis-related problems of the European society of intensive care medicine. Intensive Care Med. 1996;22(7):707–10. https://doi.org/10.1007/BF01709751.

    Article  CAS  PubMed  Google Scholar 

  6. Vanat A, Lee JW, Elkhider H, et al. Multimodal prediction of favorable outcome after cardiac arrest: a cohort study. Crit Care Med. 2023;51(6):706–16. https://doi.org/10.1097/CCM.0000000000005841.

    Article  PubMed  PubMed Central  Google Scholar 

Download references

Acknowledgements

We would like to thank the Federal Statistical Office of Germany for their support and provision of data.

Funding

The Internal Institutional Research Funds from the Department of Anaesthesiology, Intensive Care and Pain Therapy, University Hospital Frankfurt, Goethe University, Frankfurt, Germany, supported this study.

Author information

Authors and Affiliations

Authors

Contributions

All authors contributed to the manuscript. BF formulated the idea; BF and TJ drafted the manuscript. JK, GL, OO, FP and KZ provided feedback and improved the manuscript. BF coordinated the study and publication. TJ and BF conceptualized the data query. OO conducted statistical consultation. All co-authors read and had the opportunity to revise the manuscript.

Corresponding author

Correspondence to Benjamin Friedrichson.

Ethics declarations

Ethics approval and consent to participate

The Federal Statistical Office provided all data used. Due to institutional anonymisation, no conclusions about individual patients can be drawn. According to §21KHEntgG, reimbursement data are free for scientific use. The Ethics Committee of the University Hospital Frankfurt waived the need for ethical committee approval for this study (Ref: 2022–766). All data processing was performed according to the Declaration of Helsinki.

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 http://creativecommons.org/licenses/by/4.0/. The Creative Commons Public Domain Dedication waiver (http://creativecommons.org/publicdomain/zero/1.0/) 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

Jasny, T., Kloka, J., Old, O. et al. ECMO in resuscitated drowning patients: a propensity score matched sub-analysis—a response to Jouffroy et al.. Crit Care 27, 409 (2023). https://doi.org/10.1186/s13054-023-04705-1

Download citation

  • Received:

  • Accepted:

  • Published:

  • DOI: https://doi.org/10.1186/s13054-023-04705-1