key: cord-0745268-lcqqk2mu authors: Baldi, Enrico; Luce Caputo, Maria; Vanetta, Chiara; Cresta, Ruggero; Benvenuti, Claudio; Auricchio, Angelo title: A quantitative assessment of the contribution of “citizen First Responder” in the adult out-of-hospital chain of survival during COVID-19 pandemic date: 2021-07-25 journal: Resuscitation DOI: 10.1016/j.resuscitation.2021.07.024 sha: d070bf0457f6739769a67541c5bab2a36d8f7bb7 doc_id: 745268 cord_uid: lcqqk2mu nan A decrease in out-of-hospital cardiac arrest (OHCA) bystander response was observed worldwide during the COVID-19 pandemic 1 . Therefore, the importance of first responders (FRs) in initiating cardiopulmonary resuscitation (CPR) and automatic external defibrillator (AED) use has increased. FRs are police officers, firefighters (named as "professional FRs"), or off-duty medical personnel and trained laypersons (named "citizen FRs"); they are alerted if a patient experiences OHCA within close vicinity 2 . During pandemic, scientific societies stressed the importance of donning personal protective equipment (PPE) before intervening 3 ; furthermore some FRs system were temporarily suspended or limited to "professional FRs" 2 . Also in Swiss Canton Ticino only the activation "professional FRs" activity was maintained. This situation provides the unique opportunity to quantitatively assess the contribution of "citizen FRs" in OHCA resuscitation including AED use before EMS arrival. Using data from a prospective Utstein-based registry 4,5 , we compared the clinical characteristics and key resuscitation parameters of OHCAs occurred when the "citizen FRs" activation was halted (03/03/2020-26/06/2020; COVID-period) to those OHCAs occurring during the three months immediately after (27/06/2020-30/09/2020; Post-COVID period), and finally to those occurring in an historical period before COVID-19 pandemic (03/03-26/06 of years 2016-2019; Historical periods). The OHCAs characteristics are presented in Table 1 . The FRs system's activation remained unchanged during the COVID-period (73%) compared to post-COVID (81%, p=0.28) or to the historical period (61%, p=0.051). A trend toward longer FR arrival time was observed in COVIDperiod compared to historical period. A net reduction in CPR initiated by FRs before EMS arrival was observed during the COVID-period compared to the post-COVID (p<0.01) and to the historical period (p=0.02). These results remained unchanged even after considering OHCAs in whom a CPR was started by EMS. There was no significant reduction in AED use before EMS arrival in the COVID-period compared to historical period, both when considering all the confirmed OHCAs (16% vs 24%, p=0.09) and those in whom a CPR was then initiated by EMS (20% vs 28%, p=0.15). For the first time, the contribution of "citizen FRs" in OHCA management has been quantified. During COVID-19 pandemic, when only "professional FRs" system was maintained, we noticed a significant decrease in the CPR initiated by FRs before EMS arrival and an increase in FR arrival time despite an unchanged activation of the FR system. The increase in FR arrival time is an indirect indicator (and measurement) of temporary removal of the "citizen FRs" from the chain-ofsurvival; however, also the time needed to wear PPE could have played a role. We observed that the AED use before EMS arrival during the pandemic was numerically lower but statistically not significant. This contrasts other studies which reported a net reduction in AED use 1 . A possible reason for this could reside that in our region AED is most frequently deployed by "professional FRs" rather than by "citizens FR". This highlights the advantage of a three-tier system composed by "professional FRs", "citizen FRs" and ambulance. Summarizing, "citizen FRs" represent an important element in OHCA management accounting for about 15% of CPR initiated before EMS arrival. Nothing to disclose The present study received no funding. Dr Baldi's salary was partially funded by grant 733381 from the European Union Horizon 2020 Research and Innovation Program of ESCAPE-NET Out-of-hospital cardiac arrest during the COVID-19 outbreak in Italy Management of first responder programmes for out-ofhospital cardiac arrest during the COVID-19 pandemic in Interim Guidance for Basic and Advanced Life Support in Adults, Children, and Neonates with Suspected or Confirmed COVID-19: From the Emergency Cardiovascular Care Committee and Get with the Guidelines-Resuscitation Adult and Pediatric Task Forces of the Better management of out-of-hospital cardiac arrest increases survival rate and improves neurological outcome in the Swiss Canton Ticino Out-of-hospital cardiac arrests and mortality in Swiss Cantons with high and low COVID-19 incidence: A nationwide analysis Age, years (median, IQR) Cardiopulmonary Resuscitation (CPR) We confirm that the manuscript has been read and approved by all named authors and that there are no other persons who satisfied the criteria for authorship but are not listed. We further confirm that the order of authors listed in the manuscript has been approved by all of us.We confirm that we have given due consideration to the protection of intellectual property associated with this work and that there are no impediments to publication, including the timing of publication, with respect to intellectual property. In so doing we confirm that we have followed the regulations of our institutions concerning intellectual property.We understand that the Corresponding Author is the sole contact for the Editorial process (including Editorial Manager and direct communications with the office). He is responsible for communicating with the other authors about progress, submissions of revisions and final approval of proofs.Signed by the corresponding author on the behalf of all authors:Angelo Auricchio, MD PhD We wish to confirm that there are no known conflicts of interest associated with this publication and there has been no significant financial support for this work that could have influenced its outcome.