[Implementation of a smartphone-based first-responder alerting system]

Out-of-ospital cardiac arrest & Smartphonespndr trial ( Trial): Methodology and study protocol of a pre-post-design trial of the effect of implementing a smartphone alerting system on survival in out-of-hospital cardiac arrest

Background

Since 2021, international guidelines for cardiopulmonary resuscitation recommend the implementation of so-called "life-saving systems". These systems include smartphone alerting systems (SAS), which enable dispatch centres to alert first responders via smartphone applications, who are in proximity of a suspected out-of-hospital cardiac arrest (OHCA). However, the effect of SAS on survival remains unknown.

Aim

The aim is to assess the rate of survival to hospital discharge in adult patients with OHCA not witnessed by emergency medical services (EMS): before and after SAS implementation.

Design

Multicentre, prospective, observational, intention-to-treat, pre-post design clinical trial.

Population

Adults (aged ≥ 18 years), OHCA not witnessed by EMS, no traumatic cause for cardiac arrest, cardiopulmonary resuscitation initiated or continued by EMS.

Setting

Dispatch-centre-based.

Outcomes

Primary: survival to hospital discharge. Secondary: time to first compression, rate of basic life support measures before EMS arrival, rate of patients with shockable rhythm at EMS arrival, Cerebral Performance Category at hospital discharge, and duration of hospital stay.

Sample size

Assuming an absolute difference in survival rates to hospital discharge of 4% in the two groups (11% before implementation of the SAS versus 15% after) and 80% power, and a type 1 error rate of 0.05, the required sample size is N = 1,109 patients per group (at least N = 2,218 evaluated patients in total).

Conclusions

The HEROES trial will investigate the effects of a SAS on the survival rate after OHCA.

Trial registration

German Clinical Trials Register (DRKS, ID: DRKS00032920).

Automated and app-based activation of first responders for prehospital cardiac arrest: an analysis of 16.500 activations of the KATRETTER system in Berlin

BACKGROUND

Bystander CPR is one of the main independent factors contributing to better survival after out-of-hospital cardiac arrest. Simultaneously, the rate of bystander CPR in Germany is below the European average. First responder applications (apps) contribute to reducing the time period without CPR (no-flow time) until professional help can arrive on-scene.

METHODS

The KATRETTER app was introduced in Berlin as one of the first apps in Europe which do not require any medical qualifications to register as a first responder. The activation of volunteer first responders for suspected cardiac arrest cases through the Berlin Emergency Medical Services integrated control center was evaluated based on data collected between 16 Oct 2020 and 16 Oct 2022. Our descriptive analysis includes the number of registered first responders, number of activations, the number and percentages of accepted activations, as well as all reports where first responders arrived at the scene.

RESULTS

As of 15 Oct 2022, a total of 10,102 first responders were registered in the state of Berlin. During this specified period, there were 16.505 activations of the system for suspected out-of-hospital cardiac arrest. In 38.4% of the accepted cases, first responders documented patient contact, and in 34.6% of cases with patient contact, CPR was performed. Only 2% of registered first responders did not have any medical qualifications.

CONCLUSIONS

Smartphone-based first responder applications should not be understood as a means of alerting professional help, but rather like a digitally amplified "call for help" in the vicinity of an emergency location. A large number of first responders can be recruited within 24 months, without large-scale public relations work necessary. No qualifications were required to become a first responder, contributing to a low-threshold registration process with the effect of a more widespread distribution of the app and cost reduction during implementation.

[The new 2021 resuscitation guidelines and the importance of lay resuscitation]

Lay resuscitation is one of the most important measures to increase the survival rate of patients after out-of-hospital cardiac arrest. While European countries, and especially Scandinavian countries, achieve lay resuscitation rates of over 80%, the rate in Germany is only around 40%. The 2021 Resuscitation Guidelines updated by the European Resuscitation Council give special weight to Systems Saving Lives and focus on resuscitation by laypersons. The Systems Saving Lives emphasize the interplay between all actors involved in the chain of survival and thereby specify the link between the emergency service and the general population.Based on the BIG FIVE survival strategies after cardiac arrest, five key strategies are outlined that can achieve the greatest improvement in survival. These are (1) increasing lay resuscitation rates through campaigns and KIDS SAVE LIVES school-based resuscitation training, (2) implementing telephone resuscitation in dispatch centers, (3) first responder systems, (4) advanced life support, and (5) specialized cardiac arrest centers.