A Study on the Impact of a New Canton-Wide First Responder System in Zug, Switzerland, on Survival After Adult Cardiac Arrest-Examining Early Life-Saving Organized Help, Fast Defibrillation, and Improved Outcomes for Out of Hospital Cardiac Arrest

NCT07323667 | Enrolling By Invitation

• 1 other identifier: 2025-01169
• Study Type: observational
• Target: 250
• Locations: 1 country
• Sites: 1

Brief Summary

REVIVE Zug: Improving Emergency Response for Out-of-Hospital Cardiac Arrest Out-of-hospital cardiac arrest (OHCA) represents one of the most time-critical medical emergencies, where rapid recognition and immediate intervention are decisive for survival and neurological outcome. Early activation of emergency services, prompt initiation of cardiopulmonary resuscitation, and rapid defibrillation using automated external defibrillators (AEDs) are key components of the chain of survival. In many regions, organized First Responder systems-such as fire services, police forces, and trained lay responders supported by dispatcher-assisted instructions-arrive at the scene before emergency medical services (EMS) and initiate life-saving measures. Evidence from multiple EMS systems indicates that the early involvement of First Responders is associated with higher rates of return of spontaneous circulation (ROSC) and improved survival to hospital discharge with favorable neurological outcomes. Regions with well-established First Responder networks consistently report better OHCA outcomes compared with regions without such systems. In the canton of Zug, a comprehensive First Responder system has recently been implemented alongside an established hybrid EMS response model. In this system, resuscitation efforts are led either by an Emergency Physician (EP) or by a highly trained Critical Care Paramedic (CCP), depending on operational availability. Both roles operate within clearly defined competencies and provide the full scope of advanced prehospital care. This hybrid leadership model offers a unique opportunity to examine whether the professional background of the team leader influences resuscitation outcomes in real-world clinical practice. The REVIVE Zug study aims to evaluate the impact of the canton-wide First Responder system on outcomes following OHCA. Key outcomes of interest include ROSC rates, hospital admission after cardiac arrest, the occurrence of shockable rhythms at EMS arrival, and outcomes achieved before EMS arrival. In addition, the study explores whether team leadership by an EP or a CCP is associated with differences in resuscitation outcomes. Further analyses focus on time intervals within the chain of survival, such as time from cardiac arrest to arrival of organized help and time to first defibrillation, as well as on event timing and basic demographic characteristics. The study is based on anonymized data from established EMS quality registries and the national Swiss Reca database. By comparing OHCA cases before and after implementation of the comprehensive First Responder system, the project seeks to provide robust, practice-oriented evidence to inform future development of prehospital emergency care systems in Switzerland and comparable settings.

Conditions

Cardiac Arrest With Successful Resuscitation; Cardiac Arrest (CA); Resuscitation; Emergency Medical Services; First Aid; Defibrillators; Cardiopulmonary Resuscitation (CPR); Bystander Effect; Survival Rate; Critical Care Medicine; Paramedical Professionals

Keywords

OHCA; Resuscitation; First responder; AED; Automated external Defibrillator; Return of spontaneous circulation; ROSC; Critical care paramedic; Emergency physician; Prehsopital care; Paramedic-led care; Physician-led care; Switzerland

Outcome Measures

Primary Outcomes (3)

• Return of Spontaneous Circulation (ROSC) prior to arrival of EMS.

  Definition: Number and proportion of out-of-hospital cardiac arrest (OHCA) patients achieving ROSC prior to arrival of EMS.

  Time Frame: From cardiac arrest onset (as recorded by bystander/witness or dispatch log) until EMS arrival on scene (time-stamped in EMS run sheet); assessed up to 60 minutes.

• Hospital admission after OHCA

  Definition: Number and proportion of OHCA patients who are admitted to the hospital (survived to hand-over at the emergency department or ICU).

  From cardiac arrest onset until documented handover at the ED or ICU (time-stamped in EMS/hospital record); assessed up to 24 hours.

• Occurrence of shockable rhythm at EMS arrival

  Definition: Number and proportion of patients presenting with a shockable cardiac rhythm (ventricular fibrillation/pulseless ventricular tachycardia) upon first EMS assessment.

  Baseline (initial rhythm documented at EMS arrival on scene).

Secondary Outcomes (7)

• Prehospital resuscitation outcome by EMS team leadership (Emergency Physician vs Critical Care Paramedic)

  From EMS arrival on scene until hospital handover (ED/ICU) while in ROSC or death pronounced on scene; assessed up to 6 hours.

• Time from Cardiac Arrest to Arrival of Organized Help

  Baseline (index OHCA event; prehospital interval, measured once).

• Time to First Defibrillation

  From estimated cardiac arrest onset (witness/dispatch record) until first defibrillation (defibrillator time-stamp/EMS record); assessed up to 60 minutes.

• Event Timing

  At cardiac arrest onset (baseline).

• Demographics (Age, Gender)

  Baseline (at cardiac arrest onset)

Study Arms (2)

Cohort 1: Patients with OHCA before the implementation of First Responder system (retropersp.)

Cohort 1: Pre-Implementation Group Patients who experienced out-of-hospital cardiac arrest (OHCA) in the canton of Zug before the introduction of the comprehensive First Responder system (retrospective cohort).

Cohort 1: Patients with OHCA after the implementation of First Responder system (propersp.)

Cohort 2: Post-Implementation Group Patients who experienced out-of-hospital cardiac arrest (OHCA) in the canton of Zug after the introduction of the comprehensive First Responder system (prospective cohort).

Eligibility Criteria

• Age: 18 Years+
• Sex: all
• Healthy Volunteers: No
• Age Groups: Adult (18-64), Older Adult (65+)
• Sampling Method: Non-Probability Sample

Study Population

The study population will consist of individuals who experienced out-of-hospital cardiac arrest (OHCA) within the canton of Zug, Switzerland. Participants will be identified based on entries in local emergency medical services (EMS) registries and the national Swiss Reca registry. The population reflects all eligible OHCA cases attended by the Zug EMS, including both pre- and post-implementation periods of the First Responder system.

You may qualify if:

• Adults (18 years or older) who experienced out-of-hospital cardiac arrest (OHCA) in the canton of Zug.

You may not qualify if:

• Patients younger than 18 years (pediatric cases).
• Patients with a documented refusal (written or verbal) to use data for research purposes.

Sponsors & Collaborators

• Felix Brinkmann: lead

Study Sites (1)

Rettungsdienst des Kantons Zug // Emergency Medical Service of the Canton Zug

Zug, Canton of Zug, 6300, Switzerland

Location

Related Publications (10)

• Bjornsson HM, Bjornsdottir GG, Olafsdottir H, Mogensen BA, Mogensen B, Thorgeirsson G. Effect of replacing ambulance physicians with paramedics on outcome of resuscitation for prehospital cardiac arrest. Eur J Emerg Med. 2021 Jun 1;28(3):227-232. doi: 10.1097/MEJ.0000000000000786.

  PMID: 33709992 BACKGROUND

• Bujak K, Nadolny K, Trzeciak P, Galazkowski R, Ladny JR, Gasior M. Does the presence of physician-staffed emergency medical services improve the prognosis in out-of-hospital cardiac arrest? A propensity score matching analysis. Kardiol Pol. 2022;80(6):685-692. doi: 10.33963/KP.a2022.0109. Epub 2022 Apr 21.

  PMID: 35445741 BACKGROUND

• Kern M, Jansen G, Strickmann B, Kerner T. Advancements in Public First Responder Programs for Out-of-Hospital Cardiac Arrest: An Updated Literature Review. Rev Cardiovasc Med. 2025 Jan 22;26(1):26140. doi: 10.31083/RCM26140. eCollection 2025 Jan.

  PMID: 39867188 BACKGROUND

• Schwaiger D, Krosbacher A, Eckhardt C, Schausberger L, Baubin M, Rajsic S. Out-of-hospital cardiac arrest: A 10-year analysis of survival and neurological outcomes. Heart Lung. 2025 Sep-Oct;73:1-8. doi: 10.1016/j.hrtlng.2025.04.003. Epub 2025 Apr 18.

  PMID: 40250261 BACKGROUND

• Oosterveer DM, de Visser M, Heringhaus C. Improved ROSC rates in out-of-hospital cardiac arrest patients after introduction of a text message alert system for trained volunteers. Neth Heart J. 2023 Jan;31(1):36-41. doi: 10.1007/s12471-021-01656-6. Epub 2022 Jan 6.

  PMID: 34993887 BACKGROUND

• Oving I, de Graaf C, Masterson S, Koster RW, Zwinderman AH, Stieglis R, AliHodzic H, Baldi E, Betz S, Cimpoesu D, Folke F, Rupp D, Semeraro F, Truhlar A, Tan HL, Blom MT; ESCAPE-NET Investigators. European first responder systems and differences in return of spontaneous circulation and survival after out-of-hospital cardiac arrest: A study of registry cohorts. Lancet Reg Health Eur. 2020 Nov 20;1:100004. doi: 10.1016/j.lanepe.2020.100004. eCollection 2021 Feb.

  PMID: 35104306 BACKGROUND

• Nehme Z, Andrew E, Bernard S, Haskins B, Smith K. Trends in survival from out-of-hospital cardiac arrests defibrillated by paramedics, first responders and bystanders. Resuscitation. 2019 Oct;143:85-91. doi: 10.1016/j.resuscitation.2019.08.018. Epub 2019 Aug 17.

  PMID: 31430512 BACKGROUND

• Krammel M, Lobmeyr E, Sulzgruber P, Winnisch M, Weidenauer D, Poppe M, Datler P, Zeiner S, Keferboeck M, Eichelter J, Hamp T, Uray T, Schnaubelt S, Nuernberger A. The impact of a high-quality basic life support police-based first responder system on outcome after out-of-hospital cardiac arrest. PLoS One. 2020 Jun 2;15(6):e0233966. doi: 10.1371/journal.pone.0233966. eCollection 2020.

  PMID: 32484818 BACKGROUND

• Siman-Tov M, Strugo R, Podolsky T, Rosenblat I, Blushtein O. Impact of dispatcher assisted CPR on ROSC rates: A National Cohort Study. Am J Emerg Med. 2021 Jun;44:333-338. doi: 10.1016/j.ajem.2020.04.037. Epub 2020 Apr 15.

  PMID: 32336582 BACKGROUND

• Salhi RA, Hammond S, Lehrich JL, O'leary M, Kamdar N, Brent C, Mendes de Leon CF, Mendel P, Nelson C, Forbush B, Neumar R, Nallamothu BK, Abir M; CARES Surveillance Group. The association of fire or police first responder initiated interventions with out of hospital cardiac arrest survival. Resuscitation. 2022 May;174:9-15. doi: 10.1016/j.resuscitation.2022.02.026. Epub 2022 Mar 4.

  PMID: 35257834 BACKGROUND

MeSH Terms

Conditions

Heart Arrest

Condition Hierarchy (Ancestors)

Heart Diseases; Cardiovascular Diseases

Study Design

• Study Type: observational
• Observational Model: COHORT
• Time Perspective: OTHER
• Target Duration: 14 Days
• Sponsor Type: OTHER GOV
• Responsible Party: SPONSOR INVESTIGATOR
• PI Title: Principal Investigator

Study Record Dates

• First Submitted: June 25, 2025
• First Posted: January 7, 2026
• Study Start: July 25, 2025
• Primary Completion (Estimated): June 30, 2027
• Study Completion (Estimated): August 31, 2027
• Last Updated: January 7, 2026

Record last verified: 2025-06

Data Sharing

• IPD Sharing: Will not share

Locations

CH (1)