Semi-Automatic and Automatic AEDs: What's the Difference?

The popularity of Automated External Defibrillators (AED's) in airports, schools, sports arenas, office buildings, and retail stores means that people who experience sudden cardiac arrest have a better chance of survival than ever before. Yet there are some key differences in the types of AED's available where people gather that may prove to be important in the event of an emergency.

Semi-Automatic AED's

HeartSine samaritan PAD 350P AED An example of a semi-automatic AED
Semi-automatic AEDs have the ability to read the underlying heart rhythm of the victim of sudden cardiac arrest and determine whether the heart rhythm would benefit from an electrical shock. They are generally equipped with two buttons - an on/off button and a button that actually administers the shock. Once the electrodes are placed on the victim's body, the AED will read the heart rhythm and prompt the rescuer to push the shock button at the appropriate time. It will then notify the rescuer when it is safe to resume CPR. During compressions, the AED rereads the person's heart rhythm, makes adjustments to the level of electrical shock it administers and prompts the rescuer to once again push the shock button. The entire process is designed for the lay person bystander to place the electrode pads and administer shocks without the assistance of a medical professional, but interface from a user is required for the AED to work.

Automatic AED's

AED Physio Control Lifepak CR Plus The Physio-Control LIFEPAK CR Plus Fully Automatic AED is designed for anyone to use
Automatic AED's are similar to their semi-automatic counterparts in many ways. They read the underlying heart rhythm of a victim and administer an electrical shock, but they are equipped with only one button - the on/off button. After electrode pads have been placed and the device has been started, an automatic AED will cycle through a rescue protocol automatically. Rescuers performing CPR are alerted when the device will administer the first shock and when it is safe to resume CPR, but the user is not required to interact with the AED once it has been started.

Which Device is Better?

There is no cut and dried answer to which device is better. Many people are uncomfortable with administering an electrical shock by a button but are confident using an automatic device that will do it for them. This stems from a lack of understanding about how AED's work. Neither semi-automatic or automatic versions will shock a victim unless they have a heart rhythm that would benefit from it. However, most people believe they will hurt a person if they are left to administer an electrical shock themselves. Likewise, those who have training in rescue efforts prefer the control a semi-automatic AED offers. Using an automatic AED carries the risk of bystander injury if those attempting to save a victim are not clear before the shock occurs. For more information on which AED is right for you or to discuss your equipment needs, contact one of the equipment specialists at One Beat Medical. Not only can they evaluate your environment and help you decide which AED is right for you, but they can also provide information that is vital to your AED plan.