How to Use an AED

AEDs (Automatic External Defibrillators), have been shown to dramatically increase the survival rate of people suffering from cardiac arrest, when used swiftly in the first 3 to 5 minutes of the person collapsing. An AED will automatically determine the heart rhythm of a victim without a pulse, and if the victim is in ventricular fibrillation, shock the victim’s heart in an attempt to restore its rhythm to normal. AEDs are found in many public areas including most malls, stadiums and airports. Since time is the most crucial factor in a cardiac emergency, it is important for the general public to understand how to use an AED.

You will need

  • AED
  • Assistance


  1. When a person collapses, call 911 immediately and get medics en route. If there are other people around, choose someone specific and instruct them to call emergency and explain the situation.
  2. Determine whether the collapsed victim is breathing or not. If the victim is breathing, they have a pulse. If the victim is not breathing, begin rescue breathing and chest compression.
  3. Ask a bystander to take over CPR while you apply the AED to the victim. Uninterrupted CPR is an important factor in increasing the recovery rate of cardiac arrest patients. Always ensure that someone is providing CPR for the victim unless the AED machine is actively analysing or shocking the victim.
  4. 4. Ensure that the adhesive pads are attached to a cable which is plugged into the AED machine.
  5. Bare the victim’s chest and attach the adhesive pads in the appropriate locations. The AED should include a diagram indicating where each pad goes; always follow the instructions on the AED.
  6. Turn on the AED.
  7. Stop CPR and say, “CLEAR!” ensuring that nobody is touching the victim; push the Analyse button on the AED machine. The AED will not be able to analyse the victim’s heart rhythm accurately during CPR.
  8. The AED will automatically analyse the heart rhythm of the victim and inform the rescuer, whether shocks are indicated. A shock is indicated only if the victim’s heart is in ventricular fibrillation. If a “no shock” message is received it can mean one of three things: the victim that was thought to have no plus, does have one; the victim has regained a pulse; or the victim is without a pulse but is not in a ‘shockable’ rhythm. In the these cases continue to step 12.
  9. If the AED indicates that a shock is required, ensure that everyone is clear of the victim then apply the shock by pressing the shock button on the AED machine. Immediately following the shock, begin CPR for approximately 2 minutes.
  10. Do not remove the AED pads while giving the CPR.
  11. Check the victim’s rhythm with the AED after 2 minutes of CPR. Revert to step 8. If indicated by the AED, provide the victim with another shock.
  12. If the machine gives a “no shock” message after analysis, check the victim’s pulse and breathing. If a pulse is present, monitor the victim’s airway and provide rescue breathing as needed.


  • Remember that the guidelines given are not a substitute for AED training.
  • Note that CPR should not be interrupted while the adhesive pads are being applied.

Do Not

  • Use an AED on a trauma patient.
  • Use an AED on a child under 1 year of age.
  • Use an AED on a victim with a pulse.