AED Simulation

Understanding Automated External Defibrillators (AEDs)

Defibrillation is the definitive treatment for sudden cardiac arrest commonly caused by ventricular fibrillation.  This in turn arises from a heart attack, drowning, electric shock or other problems.   It is important that defibrillation be done soon and automated external defibrillators (AED) are made to be readily available and easy to use.  They are designed to be less expensive than traditional defibrillators and have voice guided prompting to encourage their use by non-medical personnel.  AEDs work by analyzing the patients’ electrocardiogram which is sensed through the adhesive defibrillator pads and prompting the operator through the necessary steps from applying the pads to performing CPR if needed.  AEDs look for ventricular fibrillation and rapid ventricular tachycardia associated with a pulse-less unresponsive patient.  Biphasic defibrillation waveforms are most commonly administered by most AEDs.  Some models make a distinction between being automatic and semi-automatic. Semi-automatic in this instance refers to the user having to manually push the shock button.  Truly automatic units will administer the shock without needing an operator.  Some units will feature a monitor that will display the electrocardiogram.  Units will vary in the amount of coaching and prompting they provide for the user through the CPR process.  Those AEDs which feature more prompting may be more suitable for so-called “Public Access Defibrillation” where users untrained in life support would be using them.

Adult Cardiopulmonary Resuscitation (CPR) with AED:

Be sure to check with the American Heart Association for the latest CPR guidelines

Adult CPR is for victims aged 8 and older.  CPR basically involves giving chest compressions and breaths to the victim.  When an AED is available, the rescuer will usually be guided through this process by the AED.  The AED will instruct on CPR application and will also analyze and advise on shocking the patient when appropriate.  Currently, the recommendation for adults is to give 2 breaths followed by 30 compressions.  The compression rate is 100 per minute with a chest compression depth of 1.5 to 2 inches.

The entire CPR process with an AED comprises several steps in a specific sequence which most AEDs will prompt you through:

1. Securing the area.
2. Checking for patient responsiveness. 
3. Calling for help if the patient is non-responsive or in trouble.
4. Check breathing.  (Tilt back head to open the airway and watch for signs of breathing).
5. Give 2 breaths if the victim is not breathing.
6. Give 30 chest compressions.
7. Repeat these last 2 steps until an AED is connected or the victim starts to move. 
8. Apply adhesive defibrillation pads. 
9. Wait for the AED to analyze the electrocardiogram.
10. Shock the patient if the AED indicates to do so.
11. Perform 2 minutes of CPR.
12. After 2 minutes, stop CPR and allow the AED to analyze the electrocardiogram again.
13. Repeat step number 10 and 11 or if no shock advised, start CPR if appropriate.