Defibrillators

Defibrillators

Defibrillators are designed to be simple, safe, and effective, even for someone with no medical training. In a cardiac emergency, you don’t need to be a professional to make a difference. If you can follow instructions, you can use a defibrillator.

Automated External Defibrillators (AEDs) talk you through what to do, step by step. Once you turn the machine on, it guides you with clear voice prompts: showing you where to place the pads, when to begin CPR, and whether a shock is needed. And importantly, it will only deliver a shock if the person’s condition requires it, so you can’t use it by mistake.

Defibrillators are made for use in everyday settings. You’ll find them in schools, gyms, workplaces, construction sites, shopping centres, and community buildings. Many are also installed outdoors in secure cabinets, which need to be wired by a qualified electrician to protect the device and keep it operational in all weather.

So why does this matter? Because cardiac arrest can strike anyone, anywhere, regardless of age, lifestyle, or medical history. In the UK, roughly 30,000 cardiac arrests happen each year outside of the hospital. The average ambulance response time is around eight minutes, but a person’s chance of survival drops by about 10% for every minute without help. By using a defibrillator, you could increase a person’s survival chances by up to 70%*. 

That’s why access to a defibrillator and the confidence to use it are so critical. If you have one at your location, make sure people know where it is. And if you don’t, find out where the nearest one is in your area.

Why is a defibrillator important?

Cardiac arrest can strike without warning — regardless of a person’s age, health, or lifestyle. It can happen to anyone, anywhere. That’s why having a defibrillator (AED) close by isn’t just a precaution; it’s a vital safety measure.

In the UK, around 30,000 people suffer a cardiac arrest outside of a hospital each year. Every minute without help reduces a person’s chance of survival by 10%. With ambulance response times averaging around 8 minutes, waiting isn’t an option. Immediate access to a defibrillator can mean the difference between life and death.

Defibrillators are designed to be easy to use, making them an essential addition to workplaces, public buildings, and community spaces. Whether you’re responsible for employees, customers, or visitors, having an AED on-site shows a commitment to their safety and could save a life when every second counts.

When to use a defibrillator?

A defibrillator should be used immediately if someone is unresponsive, not breathing, or not breathing normally — signs that they may be in cardiac arrest. In these moments, acting quickly is critical.

An AED (Automated External Defibrillator) is designed for exactly this type of emergency. It works by delivering a controlled electric shock to the heart, helping to stop irregular activity and restart a normal rhythm. Used alongside CPR, it greatly increases a person’s chances of survival.

Modern AEDs are built to be simple and safe. As soon as you turn the device on, it gives clear voice and visual instructions to guide you through each step, from placing the sticky electrode pads on the chest to performing chest compressions. The machine will only deliver a shock if it detects that one is needed, so there's no risk of using it on someone who doesn’t require it.

Will I be sued for using a defibrillator?

No, you will not be sued for using a defibrillator in an emergency.

Many people worry about legal consequences, but the truth is, defibrillators are designed to be safe and simple to use. They only deliver a shock if the device detects it’s medically needed, so there’s no danger of harming someone accidentally.

Using a defibrillator to help someone in cardiac arrest is an act of emergency first aid, and you’re protected when acting with good intentions. Don’t let fear of doing the wrong thing stop you from trying to save a life. 

Automatic vs semi-automatic AEDs

You’ll find that there are two main types of defibrillators: automatic and semi-automatic. While both are designed to deliver a controlled shock to restart the heart’s natural rhythm, they differ slightly in how a user delivers the shock. 

An automatic defibrillator does exactly that: it automatically delivers the shock needed for a cardiac arrest casualty. It will audibly deliver a warning for those nearby to stand clear, before automatically delivering a shock after a short pause. 

Alternatively, a semi-automatic AED requires the user to press a button to deliver the shock once the machine has advised that it’s needed. This may feel slightly daunting to the user as they have to physically deliver the shock themselves, but it can be slightly quicker. 

Both options are effective and deliver the same treatment; it may just be down to personal preference or the setting in which the AED will be needed. 

* Defibrillation within 3–5 min of a cardiac arrest can produce survival rates as high as 50%–70% (BMJ Emergency Medicine Journal)