Automated External Defibrillator

What is an AED?

An automated external defibrillator works by using a built-in computer that checks a victim’s heart rhythm through adhesive electrodes. The computer calculates whether defibrillation is needed.

If it is, a recorded voice prompts the rescuer to press the shock button on the AED. This shock momentarily stuns the heart and stops all activity. It gives the heart the chance to resume beating effectively. Audible prompts guide the user through the process. AEDs advise a shock only for ventricular fibrillation or another life-threatening condition called pulseless ventricular tachycardia.

Important Points for AED Use

  • Do not wait to get the victim medical attention. Studies have shown that if defibrillated within the first minute of collapse, the victim’s chances for survival are close to 90 percent. For every minute that defibrillation is delayed, survival decreases by 7 percent to 10 percent. If it is delayed by more than 10 minutes, the chance of survival in adults is less than 5 percent.
  • Because of their ease of use anybody can use an AED. That being said, someone with training should be the one to use the AED on a victim if present.
  • Documented regular inspections of AEDs are critical. AEDs have indicator lights that either show green or red. A red light or flashing red light indicates some problem with the AED. Dead batteries are also another common problem with AEDs. Check the manufacturer’s literature as to how often the batteries need replaced. Batteries in AEDs commonly need replaced between every two and four years.


Most people are familiar with what an AED is and probably have them in their place of work, but may not understand how they function. It is critical that everyone is at least familiar with how they work and in what situations they should be used. AEDs are often the only chance that a victim of sudden cardiac arrest will survive.

Discussion Points

  • Where is the closest AED in your work area?

Do you have any apprehension using an AED? Why?