A cardiac arrest episode is a condition where the heart stops beating completely or has a highly irregular rhythm. Because of this, blood doesn’t circulate through the body, leaving every vital organ without oxygen. This condition, if left untreated, can leave the patient with permanent damage and lead to death.
The treatment plan for cardiac arrest always starts with CPR, no matter the cause of the episode. Consisting of chest compressions, assisted breathing, and the use of an automated external defibrillator, CPR can triple the chances of survival.
Even though AEDs are a vital part of CPR, many bystanders don’t use them. In fact, almost 4000 lives could be saved yearly if bystanders use AEDs on the scene. In this article, we’ll see what are the different types of AED available, how they work, and why using one is so important.
What is an AED & How Does it Work
An automated external defibrillator (AED) is a medical device designed to restore a normal heart rhythm in a patient experiencing cardiac arrest.
The way this device works is simple yet highly sophisticated. It consists of a built-in computer, battery, and pad electrodes that are placed on the chest of the person in need. When activated, the AED can detect, analyze, and interpret the person’s heart rhythm and deliver a shock in the necessary intervals.
In hospitals, AEDs are part of crash carts and are accompanied by other life-saving supplies. Outside of a hospital setting, however, AEDs can be found in small cases in every workplace, business, school, and other public location.
Since more than 350.000 episodes of cardiac arrest happen outside of the hospital every year, using an AED is crucial.
The Different Types of AEDs
Officially, there are two different types of AEDs – public access AEDs and professional AEDs. However, it’s also possible for anyone to buy an AED and keep it in their home, especially when living with a person suffering from high-risk medical conditions. These devices are called personal or home AEDs and can also be carried in the car.
Public Access AEDs
Public access AEDs can be found in schools, workplaces, restaurants, parks, malls, and many other spaces the public frequents.
They are usually mounted on a wall and can be accessed in a similar manner as a first aid kit or a fire extinguisher. By law, AED devices must be placed in an easily-accessible space.
These AEDs are intended to be used by lay rescuers (bystanders) and are designed to work completely automatically.
Professional AEDs
Professional AEDs are the AEDs used by first responders, who usually have a higher degree of AED-use training. These AEDs aren’t available to the public and ideally shouldn’t be used by bystanders.
Professional AEDs are semi-automatic, meaning that the user needs to push a button for the device to administer a shock. They can also be manual, meaning the user has the power to adjust the strength of the shock when it is administered.
Personal (Home) AEDs
Personal or home AEDs are similar to public access AEDs and are completely automatic. They are always placed in a special case and are very easy to carry around and store. These devices are made to be portable and simple to use.
The prices for personal AEDs range from $900 to $2,500. The manufacturer of the device has to be approved by the FDA. The list of these manufacturers can be found on the FDA’s website.
When a person buys a personal, portable AED, there are a few steps they need to take in order to ensure they’re using and storing the device properly.
Registration
Your personal AED device should be registered with the manufacturer. This way, you’ll always be up to date with the newest safety device-specific information and updates.
Training
Even though the training isn’t legally required to use a personal or public-access AED, it’s always best to sign up for it anyway. You can find such training at your local Red Cross office or other certification providers.
It’s also optimal to have a test run of your AED to familiarize yourself with its operation.
Storage & Maintenance
If you’re keeping your AED at home, make sure it’s placed away from children’s reach in a dark, dry, cold space. The batteries within the AED shouldn’t be exposed to high temperatures.
If carrying your AED in your car, pick a spot where the device isn’t accessible to children but can still be pulled out quickly when needed. Make sure the space you choose is dark, dry, and doesn’t get too hot. Many personal AED users choose the trunk of their vehicles.
You should check the batteries within your AED often and change them every 4 years. You should also replace the pads as needed and keep a few spare pairs nearby.
Staying up to date with your manufacturer is another crucial part of maintaining your AED, so check their website regularly and sign up for alerts.
Semi-Automatic vs. Fully-Automatic AEDs
Understanding the difference between semi-automatic and fully-automatic AEDs is extremely important. Even though most public access AEDs are fully-automatic, sometimes, you may run into one that’s not.
Given that every minute that passes decreases a person’s chances of survival by roughly 10%, knowing how to use both types of AEDs beforehand is crucial.
Semi-Automatic AEDs
Semi-automatic AEDs consist of a built-in computer, battery, and pad electrodes. It also features a button that needs to be pressed in order for the device to administer the shock.
To use one, you need to make sure the person’s skin is completely dry. AEDs usually come with a pair of scissors, so you can cut the clothing and place the electrodes on the bare chest.
After you’ve placed the electrodes on the chest, turn the device on and let it analyze the heartbeat. When it’s done and ready to administer the shock, you’ll need to press the button and stand aside.
Most AEDs give voice instructions to the user since they’re designed for out-of-hospital use.
Fully-Automatic AEDs
Fully-automatic AEDs consist of the same elements as semi-automatic ones, only they don’t feature a button.
This device will analyze the heartbeat and administer a shock on its own, and all the user needs to do is follow the instructions it gives out. The electrodes of the fully-automatic AED should also be placed on bare, dry skin, and no contact should be made with the patient while the shock is administered.
Before it administers the shock, the device will alarm the user which is a cue to move away from the patient. Once the shock is administered, it is safe to continue giving CPR until the next shock or until paramedics arrive.
The Importance of Using AEDs During CPR
Knowing how to use an automated external defibrillator is a life-saving skill that can make a big difference for the person experiencing cardiac arrest.
A study by a medical student at John Hopkins University analyzed almost 50.000 cardiac arrest events and found that 66.5% of patients treated with an AED by a bystander survived. The survival rate of those who didn’t receive bystander AED treatment was 43%.
It’s also important to note that patients who did receive immediate AED treatment were more likely to return to their normal neurologic levels after the event. This is because the AED helped restart the heart, which then continued pumping blood throughout the body. It helped to minimize the time vital organs like the brain were without oxygen.
The use of an AED is even more important in high-traffic cities as well as rural areas that paramedics can’t reach quickly. The typical response time is between 8-12 minutes, but in these places, it can be even longer.
Automated External Defibrillators: Conclusion
In 2020, the cardiac arrest mortality rate in the US was over 436,000. Most of these cases happened outside of the hospital.
Learning how AEDs work, where you can find them, and how you can use them is a skill everyone should have. Even though they are simple devices, it’s best to always be prepared before a high-stress situation happens.
If you’re planning on buying a home AED, make sure you’re getting a device that was designed for use by lay rescuers instead of trained professionals. Simple, FDA-approved devices work best in this setting and will help you give optimal help when it’s most necessary.