Understanding the Different AED Modes

Understanding the Different AED Modes

In situations when time is of the essence, an AED nearby can make a difference between survival and fatality. But not all AEDs are the same. There are various modes with different specifications and advantages.

An automatic external defibrillator (AED) is a small device that can shock a person’s heart back to a normal rhythm. With easy-to-follow instructions provided by the device, operating an automatic external defibrillator (AED) is a straightforward process.

If you’re new to AEDs, don’t worry. In this guide, we’ll explain the different defibrillation modes and the factors to consider in choosing the right one. Whether you’re a concerned citizen or just want to know more, we’ve got you covered.

First Things First: When Can You Use an AED?

Before diving into the different AED modes, it’s important to understand in which instances you’d need to use an AED.

There are two types of heart rhythms – shockable vs. non-shockable rhythm. In the former, an AED can restore a person’s heartbeat, while in the latter, the electrical system is intact, and using an AED will prove ineffective.

Shockable rhythm is an abnormal heart rhythm that can be corrected with a defibrillation shock. The two shockable rhythms are ventricular fibrillation (VF) and pulseless ventricular tachycardia (PVT).

In VF, the heart beats irregularly, and in VT, the heart beats too fast and in a regular pattern. The AED will signal the operator to shock the patient’s heart when it analyzes the cardiac rhythm and finds a shockable rhythm.

It’s important to keep in mind that not all cardiac arrest rhythms can be treated with electrical shocks. Asystole and pulseless electrical activity (PEA) are rhythms that cannot be treated with electrical shocks, meaning they’re non-shockable. However, quality CPR can turn them into shockable rhythms in some very lucky cases.

Types of AED Waveforms

Biphasic and monophasic waveforms are both types of electrical shock that can be delivered by an AED (Automated External Defibrillator) to treat a shockable cardiac arrest rhythm such as ventricular fibrillation (VF) or pulseless ventricular tachycardia (VT).

The main difference between biphasic and monophasic waveforms is that the biphasic waveform delivers electrical current in two directions, while the monophasic waveform delivers electrical current in only one direction. Biphasic waveform shocks start with a low-energy shock, followed by a brief pause, and then a higher-energy shock if the rhythm persists.

In contrast, a monophasic waveform delivers a single direction of electrical current at a high energy level, which can increase the risk of tissue damage and require more energy to be delivered to achieve the same effect as a biphasic shock.

AED Modes

Understanding the different AED modes is crucial in administering proper care during cardiac arrest. Choosing the appropriate defibrillation mode can have a big impact on how the scenario turns out because each mode has its own distinct characteristics and capabilities.

The user’s training and expertise, the location, and the patient characteristics all play a role in determining the best AED mode. By understanding these different modes, users can administer proper care and potentially save a life during sudden cardiac arrest:

Fully Automatic Mode

In this mode, the AED analyzes the heart rhythm of the person in cardiac arrest and delivers a shock automatically without the need for the user to press any buttons.

This can be a huge relief for someone feeling overwhelmed in a high-pressure situation. It’s also an excellent option to display in a public place where people without CPR certification frequent it.

With the fully automatic mode, the AED takes care of everything, allowing the user to focus on providing CPR and other life-saving measures. The AED fully automatic mode is an important advancement in medical technology.

Semi-Automatic Mode

The semi-automatic mode of an automatic external defibrillator (AED) is another important feature that can help save lives in an emergency situation. The user is prompted to push a button to administer a shock if necessary after the AED analyzes the victim’s cardiac rhythm in this mode.

While the semi-automatic mode requires the user to press a button to deliver the shock, it still provides important guidance and support during a high-pressure situation. The bystanders or medical persons can make adjustments to the settings based on the person’s condition and receive feedback from the device on their actions.

The semi-automatic mode is also a good option for users who may feel more comfortable having some control over the device. They can still benefit from the guidance and support provided by the AED while also being able to make some decisions based on their own knowledge and experience.

Manual Mode

The manual mode of an automatic external defibrillator (AED) is an advanced feature that requires a high level of medical training and knowledge. In this mode, the user has complete control over the device and can make decisions about when to deliver a shock based on their assessment of the person’s condition.

The manual mode is the most advanced mode of an AED and requires a high level of skill and knowledge to use effectively. Medical professionals who are trained to use the manual mode can benefit from its advanced features. The manual mode also provides the user with informed decisions about their treatment.

Factors to Consider in Choosing AED Mode

Choosing the right mode of an AED is an important decision that could potentially impact the outcome of a medical emergency. Selecting between defibrillation modes depends on several factors, including user training, the person’s condition, response time needed, environmental factors, and user comfort level:

Training and Experience of User

The mode of an automatic external defibrillator (AED) should be selected based on the user’s training and level of expertise. Fully automated mode is typically the best choice if the user is not a medical professional. If the user has medical training, the semi-automatic or manual mode may be appropriate depending on their level of expertise.

Type of Setting

AEDs can be found in a variety of high-traffic locations. Workplaces, fitness facilities, and community centers may all have AEDs – here’s which AED modes are most suitable for each:


      • In public spaces such as airports, shopping malls, and sports arenas, the fully automatic mode may be the best option. This is because these settings often have a high volume of people, and the AED may be used by someone with little to no medical training.


        • Medical environments such as hospitals and clinics may find the manual mode to be the optimal choice. They can efficiently use the manual mode as they have the skills and experience to do so. The manual mode provides detailed feedback and allows for a more personalized response based on the person’s condition.


          • In remote settings such as hiking trails or wilderness areas, the semi-automatic or manual mode may be the best option. This is because these settings may require a longer response time, and the user may need to make more informed decisions about the treatment. The semi-automatic or manual mode allows for a more personalized response based on the person’s condition and the user’s training and expertise.

        Patient Factors

        The mode of an AED should also be selected based on the person’s condition. For example, if the person is in cardiac arrest, the fully automatic or semi-automatic mode may be appropriate.

        However, if the person has an irregular heartbeat or other complex medical condition, the manual mode may be necessary. The user’s comfort level should also be taken into consideration while choosing an AED mode. If the user is not comfortable using the semi-automatic or manual mode, they may not use the device effectively.

        Understanding the different AED modes is important for selecting a mode that the user is comfortable with.


        In conclusion, multiple AED (automated external defibrillators) modes are available that can increase the survival chances of a person experiencing sudden cardiac arrest or another heart-related condition.

        The completely automated mode and the semi-automated mode are the two most popular modes.

        In fully automated mode, the AED examines the cardiac rhythm and, if necessary, administers a shock automatically without human input. The AED analyzes the cardiac rhythm in semi-automated mode, but the operator must still press a button to administer the shock.

        To improve the odds of survival during a sudden cardiac arrest emergency, understanding the different AED modes is crucial. Always be sure to properly follow the AED instructions and call 911 before doing anything else.