Letter to the Editor in regard to the “Effects of COVID-19 on in-hospital cardiac arrest: incidence, causes, and outcome” by Roedl et al.”

Dear Editor,

We have read the retrospective article entitled "Effects of COVID-19 on in-hospital cardiac arrest: incidence, causes, and outcome" by Roedl et al. published in the Scandinavian Journal of Trauma, Resuscitation and Emergency Medicine (2021; 29(30)). We want to commend the authors for this informative study and make some contributions.

In the study results, sustained return of spontaneous circulation (ROSC) was defined as stable circulation for at least 20 min. Moreover, the rates of sustained ROSC were comparable across the two study periods (2019 Non-COVID-19 period: 77% vs. 2020 COVID-19 period: 83%) [1]. These rates hint at similar outcomes across the study periods; however, the survival rates to discharge from hospital during the Non-COVID-19 period and COVID-19 period, particularly the rates of the survival of the COVID-19 positive subcohort, would provide valuable clinical data. A study collecting retrospective data from a public New York hospital during similar time periods (Non-COVID-19 period: March 1st, 2019 to May 15th, 2019; COVID-19 period: March 1st, 2020 to May 15th, 2020) reported a lower ROSC during the COVID-19 period compared to the Non-COVID-19 period (36% vs. 56%) [2]. This outcome correlated to a significantly lower survival to hospital discharge during the COVID-19 period (3% vs. 13%). Additionally, survival among COVID-19 patients experiencing IHCA was even lower (2%).

As we finalize and prepare to publish our analysis of the impact of the COVID-19 pandemic on cardiac arrest survival rates within our institution, we believe that data on the survival to discharge from Roedl’s cohort would be invaluable for both comparative reasons as well as to better characterize the effect of sars-cov2 on overall resuscitation success. To this end, we respectfully request that both survival to discharge and 30-day survival from the Roedl study be published as an addendum or otherwise be made available.

Response—Letter to the Editor in regard to the “Effects of COVID-19 on in-hospital cardiac arrest: incidence, causes, and outcome" by Roedl et al.”

• Kevin Roedl 

1. Department of Intensive Care Medicine, University Medical Centre Hamburg-Eppendorf, Martinistraße 52, 20246, Hamburg, Germany

   Kevin Roedl

To the Editor,

We thank Krieg et al. for the interest in our study and for their valuable comments. We agree with Krieg et al. that both study periods provided an almost similar rate of return of spontaneous circulation (ROSC) (2019: 77% vs. 2020: 83%, p = 0.237) [3]. In our cohort 40/84 (48%) and 34/93 (37%) were discharged alive from hospital in the 2019 and 2020 period (p = 0.551), respectively. Furthermore 26/40 (65%) and 27/34 (79%) had a favourable neurological outcome at ICU discharge in the 2019 and 2020 period, respectively. According the small sub-cohort of twelve patients with COVID-19 we can report that 6/12 (50%) of patients survived to hospital discharge, 5/6 had favourable neurological outcome. Due to the retrospective nature of our study, we are only able to report on patient survival till hospital discharge.

Although, ROSC rates hint a similar outcome we observed differences in rates to hospital discharge across the two study periods. This may be attributable to the location of cardiac arrest which shifted more towards the ICU in the 2020 period. Cardiac arrest occurring in the ICU shows clinically important differences compared to cardiac arrest occurring in a general ward [4, 5]. Due to this significant shift in location of cardiac arrest within the two study periods conclusion regarding outcome should be drawn cautious and ROSC may not present the most reliable indicator for survival to hospital discharge.