What should be the first action taken by someone witnessing a cardiac arrest?

In the event of witnessing a cardiac arrest, the first action should be to call for emergency medical services. This step is critical because it ensures that professional help is on the way as quickly as possible. Time is of the essence in a cardiac arrest situation, and the chances of survival decrease significantly with each passing minute without intervention.

Calling for emergency medical services allows for the prompt arrival of advanced medical providers who can deliver definitive care, including medications and advanced airway management, that cannot be administered by bystanders. This action also can make use of a speakerphone or other communication devices to ensure that help is on the way while further actions are taken.

While checking for a pulse, administering rescue breaths, and performing chest compressions are important components of the response to cardiac arrest, these actions should occur after emergency services have been alerted. In many modern protocols, especially in cases of adult cardiac arrest, initiating high-quality chest compressions should begin quickly, but notifying emergency medical services must remain the initial priority to facilitate a timely and coordinated emergency response.