How exactly does an AED work?

An Automated External Defibrillator (AED) is a life-saving device used in the event of cardiac arrest. Many people are familiar with the device, but don't know exactly what it does or how it works. In this blog post, we explain step by step how an AED can save lives.

What is an AED?

An AED is a portable device that can deliver an electric shock (defibrillation) to the heart of someone experiencing cardiac arrest. This shock can essentially "reset" the heart and restore it to a normal rhythm. An AED is designed for laypeople, so even people without a medical background can use it in emergency situations.

When do you use an AED?

An AED is used in the event of cardiac arrest , usually caused by ventricular fibrillation : a chaotic heart rhythm that prevents the heart from pumping blood. The first few minutes after a cardiac arrest are crucial. Every minute without help reduces the chance of survival by 7 to 10 percent. Therefore, acting quickly is vital.

Step by step: how does an AED work?

1. Turn on the device

Once you have an AED near the victim, turn it on. You can do this by pressing the on/off button or by opening the lid (depending on the model). The AED will then immediately begin speaking instructions and guide you step by step.

2. Apply electrodes

The AED includes a set of adhesive electrodes with illustrations showing where to place them: one on the upper right side of the chest, the other on the lower left side of the chest. This ensures the AED can accurately measure the heart rhythm.

3. Analysis of the heart rhythm

Once the electrodes are in place, the AED begins analyzing the heart rhythm. The device checks whether a shock is necessary. No one should touch the victim during this analysis.

4. Administer any shock

• With a semi-automatic AED : if a shock is necessary, the AED will indicate this and ask you to press a button.

• With a fully automatic AED : the AED administers the shock fully automatically, without any intervention from the rescuer.

During the shock, no one should touch the victim.

5. Resume CPR

After the shock, or if no shock is needed, the AED prompts you to resume CPR (chest compressions and breaths). Many AEDs also provide feedback on the depth and rate of chest compressions.

6. The cycle repeats itself

The AED continues to analyze the heart rhythm and guide you as long as it's connected. Continue until professional help arrives or the victim shows signs of life.

What makes an AED so special?

• Fully automatic or semi-automatic : depending on the type.

• Guidance with spoken instructions : no experience necessary.

• Some models provide feedback : for better resuscitation performance.

• Safe for use by lay people : an AED never delivers a shock unless it is necessary.

Finally

An AED is simple and effective. Thanks to its clear instructions and automatic analysis, everyone can play a crucial role in saving a life. Know where the nearest AED is located and, if possible, take a CPR course—because every second counts.

Want to learn more about different types of AEDs or training courses? Feel free to contact us or browse our offerings .