Lay responders can save lives in out-of-hospital cardiac arrest

Dispatching the public via an app as lay responders has shown to be accompanied by a 28% higher survival in patients with out-of-hospital cardiac arrest.

If lay responders are near a cardiac arrest location, the app gives instructions for CPR or AED

Dispatching the public via an app as lay responders has shown to be accompanied by a 28% higher survival in patients with out-of-hospital cardiac arrest. This survival benefit can be explained by a higher cardiopulmonary resuscitation and defibrillator use1,2.

Lay-responder systems (e.g. dispatch of the public to a cardiac arrest) are increasingly implemented around Europe, in particular in indications where time is of key importance. Previously, studies have found an association between these systems and survival after out-of-hospital cardiac arrest. A Swedish study including 8,513 cardiac arrests at 4 different study sites (i.e. 2 in Sweden, 1 in the Netherlands, and 1 in Switzerland) supported the usefulness of this approach. “Our study suggests that when emergency medical services incorporate members of the public into their systems, cardiac arrest victims are more likely to survive,” said study author Dr Martin Jonsson (Karolinska Institute, Sweden). 

The study included all out-of-hospital cardiac arrests occurring in 2016 through 2019 in 4 areas. Data from the 2 most populous regions in Sweden (i.e. Stockholm, Västra Götaland) were collected from the Swedish cardiopulmonary resuscitation (CPR) register. Information from North Holland, the Netherlands, was obtained from the ARREST database, and the Ticino Cardiac Arrest Registry was used for Ticino, Switzerland.

The system for dispatch of lay responders worked as follows: the public could sign up as lay responders via a mobile phone app/internet. They were then registered in a database and the system tracks their location. When the dispatch centre receives a call about a cardiac arrest, the dispatcher can activate the system. If lay responders are near the cardiac arrest location, they receive a notification from the app with instructions to run and perform CPR or find an automated external defibrillator (AED). 

When lay responders were dispatched, there was a 28% higher chance of CPR

Activation of lay-responders was compared with a control group regarding the use of CPR, use of AEDs, and 30-day survival following a cardiac arrest in the community. The analyses were adjusted for age, sex, location, witnessed status, emergency medical services response time, and time of day.

In 3,410 of a total of 8,513 cases, lay responders were dispatched to the victim using a smartphone application, while a lay responder was not dispatched in 5,103 cases. When lay responders were dispatched, there was a 28% higher chance of CPR (risk ratio [RR] 1.28; 95% CI 1.12–1.45; P=0.0002), and a 56% higher chance of AED use (RR 1.56; 95% CI 1.02–2.39; P=0.0390). “Most importantly, we saw a 28% higher likelihood of being alive at 30 days,” Dr Jonsson said during the presentation (95% CI 1.10–1.48; P=0.0012).

“Our study demonstrates the benefits of including the general public in the emergency response to a suspected cardiac arrest. Every second counts in these situations and lives can be saved with rapid use of AEDs and CPR,” Dr Jonsson concluded.

Notes:
1. Jonsson M. Dispatch of lay-responders is associated with bystander cardiopulmonary resuscitation, bystander defibrillation and 30-day survival following an out-of-hospital cardiac arrest. ESC Congress 2021, 27–30 August.
2. Jonsson M. Dispatch of lay-responders is associated with bystander cardiopulmonary resuscitation, bystander defibrillation and 30-day survival following an out-of-hospital cardiac arrest. Press conference, ESC Congress 2021, 27–30 August.