THE ULTIMATE GUIDE TO AEDs: The rise of the life-saving defibrillator – and what needs to be done to increase survival rates


Out of 30,000 cardiac arrest cases in the UK every year, only one in 10 people survive. But when an automated external defibrillator (AED) is used during emergency first aid, the survival chances rise to 57.1%.

These are the findings of research by the London Ambulance Service.

But as the subject of lifesaving AEDs – also known as public access defibrillators (PADs) – becomes big news, and we see increasing numbers of machines in public places, workplaces and schools, is installing an AED simply enough?

Not according to a study conducted by the Openheart Journal, which researched the global use of public access defibrillators over five years. Its findings highlighted that response time and willingness to use the machines all factored into a person’s survival rate if they go into cardiac arrest while outside hospital. 

Within the journal’s content, it reports on the findings of a study in which a group of people were questioned about AEDs – 69.3% of people knew what an AED was, but only 2.1% would attempt to retrieve and use one in a cardiac arrest situation.

The report concluded that more should be done to highlight the importance of public defibrillators and to train people and help boost confidence in using them if more lives are to be saved. 

public defibrillators

The growth of public defibrillators

The importance of AEDs became ingrained into public psyche back in summer, when Danish footballer Christian Eriksen suffered a cardiac arrest on the pitch during a Euro 2020 championship match, which he survived thanks to immediate medical attention that involved CPR and a defibrillator. Increases in sales of AED machines followed.

Following the on-pitch Christian Eriksen incident, Dr Sonya Babu-Narayan, Associate Medical Director and Consultant Cardiologist for British Heart Foundation, said: “This shocking event is a stark reminder that a cardiac arrest can strike anyone, anywhere and anytime, without warning. 

“It’s crucial that we continue to find opportunities to offer everyone training in CPR – including in secondary school education – and that we make public access defibrillators readily available in the places they are needed most. This will mean that more people could get the rapid and life-saving response that Christian received.”

The Welsh government has just announced an additional £500k to improve community access to defibrillators in an effort to boost out-of-hospital cardiac arrest survival rates. The Automated External Defibrillators bill is currently being read in Northern Ireland and CPR is due to be on the school curriculum from later this year.

Defibrillators in schools 

Last year CPR and first aid became compulsory on the school curriculum, and this month saw a major step forward in the battle for making defibrillators mandatory in schools. This is thanks to the tireless campaigning by Mark King from Liverpool, who set up the Oliver King Foundation in memory of his 12-year-old son, who died following sudden cardiac arrest while swimming a race at school in 2011. Following a meeting between Mark and Education Secretary Gavin Williamson, the subject was raised in parliament and the government is now looking into changing regulations. 

The Resuscitation Council UK’s ‘A guide to AEDs’ outlines how schools in Seattle, USA (a city with the best data in the world on cardiac arrest) reported 97 cardiac arrests over a 15 year period, with cardiac arrest occurring at one in 111 schools per year. 

The organisation highlights the importance of AEDs in schools, not least because it brings about awareness and understanding of first aid and CPR in children as part of their training, despite the fact the machines may be used infrequently. 

It also says that children have been shown to be capable of using AEDs in simulated cardiac arrest scenarios and recommends CPR training and AED familiarisation for teachers, adult staff and school pupils alike.

defibrillators heart restarter

Who does cardiac arrest affect? 

The London Ambulance Service released a cardiac arrest annual report which stated that, out of 10,000 patients in one year, the overall median age for patients was 63. However, that’s not to say that cardiac arrest does not affect people of all ages too. Quite often we hear new reports about these emergencies on the sports field of young, fit people, and according to the Oliver King Foundation, Sudden Arrhythmic Death Syndrome (SADS) kills 12 young people under the age of 35 every week in the UK.

The Resuscitation Council says there is evidence that there is inequality around cardiac arrest, with people in deprived areas or areas with greater proportion of residents from ethnic minorities being more likely to suffer, with lower incidence of bystander CPR taking place and reduced access to public access defibrillators.

Guide to AEDs and the chain of survival


What is a defibrillator? (AED/PAD)

Machines that give a high energy electric shock (defibrillation) to the heart of a person who has gone into cardiac arrest. They are intended for easy-access public use in the event of an emergency, to be used by bystanders who witness a cardiac arrest incident, who are otherwise medically untrained.

There are many kinds of models and several manufacturers and medical equipment sales companies who supply them. Check with your local ambulance service if you don’t know which model you should buy as they can help you understand the differences and talk you through costs, battery shelf life, adhesive pads (electrodes), duration of manufacturers’ guarantees and after-sales services. 

Some are made with extra features for use by highly trained responders and some contain GPS location systems and WiFi enabling for monitoring. 

An AED costs between £750 to £1,300 each, although some companies also hire them out.

What is cardiac arrest? 

It is when the heart stops pumping blood around the body and goes into an abnormal heart rhythm or stops beating entirely. This in turn could stop oxygen reaching the brain and other vital organs. 

It is not the same as a heart attack, which is when the blood supply to the heart muscle is cut off, often caused by a clot in an artery. During a heart attack, the heart still pumps blood around the body and the person will be conscious and breathing, however a heart attack can lead to cardiac arrest.

A person in cardiac arrest will lose consciousness and breathing will become abnormal or stop. Causes include heart disease, loss of blood, trauma, electrocution or SADS, which is usually caused by a genetic defect.

Cardiac Arrest warning adverts

What does a defibrillator do?

While cardiopulmonary resuscitation (CPR) can keep blood flowing to your heart and brain for a certain time, defibrillators shock the heart and restore it to its normal rhythm, which improves survival chances dramatically. 
This is why using CPR and a defibrillator go hand-in-hand during a cardiac arrest emergency.

How effective are AED defibrillators?

Quite simply, they save lives, even when being used by non-trained first responders. A cardiac arrest casualty’s chance of survival decreases by around 10% with every minute that defibrillation is delayed. 
Only rarely is the ambulance service able to attend and provide defibrillation early enough to save someone, and the best way of ensuring prompt defibrillation is for someone nearby to use an AED to deliver the shock that may stop that person from dying.
Following the on-pitch Christian Eriksen incident, Dr Sonya Babu-Narayan, Associate Medical Director and Consultant Cardiologist for British Heart Foundation, said: “This shocking event is a stark reminder that a cardiac arrest can strike anyone, anywhere and anytime, without warning. 
“It’s crucial that we continue to find opportunities to offer everyone training in CPR – including in secondary school education – and that we make public access defibrillators readily available in the places they are needed most. This will mean that more people could get the rapid and life-saving response that Christian received.”

Where can I find a defibrillator near me 

There is a growing number of PADs around the UK, especially in busy places such as shopping centres, train stations, sporting stadiums, airports and any other community spaces. 
To find the closest defibrillator in the event of a cardiac arrest emergency, dial 999 and the operator will help you find the nearest registered machine and help you gain access to it. All registered machines will be available on The Circuit, the national network launched in 2019. 
While schools and workplaces are catching up with getting AEDs installed, it is not yet a legal requirement to implement a machine in any particular setting. There are now efforts being made to introduce legislation to make AEDs mandatory in workplaces and other public areas. 
Visit our roundup of the number of public access defibrillators by UK cities here.

How to use a defibrillator

As the figures we analysed showed, people may find using a defibrillator daunting and think it could be too complicated to use without prior training. However, the machines have been designed especially for novices who have never seen an AED before. 

Take these simple steps if someone is in cardiac arrest:

  • Call 999
  • Begin administering CPR
  • Ask someone else to speak to the emergency operator, to find a defibrillator and bring it to the patient, following instructions over the phone or via the AED’s verbal prompts. Continue to deliver CPR throughout.
  • Turn on the defibrillator and follow the instructions. Ideally someone else will do this while you’re continuing CPR.
  • Take the pads from the sealed pack and remove any clothing or dampness from the skin.
  • Remove backing paper and attach the pads to the chest (see images below).
  • An AED will only administer a shock if the patient’s heart is in shockable rhythm and should provide ongoing instructions about CPR.
  • Do not touch the patient while the AED is giving a shock.
  • If the patient’s heart is not presenting with a shockable rhythm, continue to do CPR until the emergency services arrive.

A reminder: And AED is not a substitute for CPR – they must go together. If you’re alone, however, the AED must be your priority.

How to use a defibrillator on a child

Some AEDs contain paediatric pads, so use these on a child following manufacturers’ guidance if they’re available. However, if only adult pads are on hand these can be used on a child in cardiac arrest.

Guide to AEDs explaining how to use a defibrillator on a child

The past and future of AED defibrillators

The portable defibrillator was invented by ‘the father of emergency medicine’, Frank Pantridge. The cardiologist from Northern Ireland created the first lifesaving machine in 1965 using car batteries for the current. It would take until 1990 before all front-line ambulances in the UK were fitted with the devices. 

Now AEDs are becoming big news, with stories hitting the headlines every week about funds raised, donations made, calls for legislation and training, and the latest life saved by an AED.

In fact, the global defibrillators market is projected to be worth $11.7 billion by 2025, up from $9.6 billion in 2019, according to a report outlined in Markets and Markets.

And Engineering and Technology (E&T) Magazine has reported that defibrillators could even be delivered by drones in the not-too-distant future. The Karolinska University Hospital in Stockholm, Sweden, performed the first-ever study to investigate the feasibility of drone delivery of AEDs to patients with suspected cardiac arrest outside of hospital. 

Dr Sofia Schierbeck, author of the study, said: “We believe that novel ways to provide AEDs are needed to increase the chance of survival in these patients.”

In fact, during the four months in which the trial took place,12 drones were deployed in real cardiac arrest cases and an AED was successfully delivered to 11 of these sites, being carefully lowered by a winch from 30m. The drone arrived before the ambulance in 64% of cases, on average 1:52 minutes earlier than the ambulance.

Dr Schierbeck added: “Our study shows that it is not only possible but can be quicker than an ambulance. This is the first ever proof of concept and the starting point for the use of drones in emergency medicine worldwide.”

AEDS in the workplace 

Most cardiac arrest take place within the home or workplace. While figures for the UK are difficult to locate, we know that in the US, 400 deaths from cardiac arrest are reported to Occupational Safety and Health Administration each year. Resus reinforces the point in its ‘A guide to AEDs’: “Having an AED in the workplace will ensure that a defibrillator is available immediately to give a person in cardiac arrest the best chance of survival, rather than waiting for the ambulance service to attend. Training in Emergency First Aid at work is not only a legal requirement, but essential in administering AED and CPR effectively. ”

The average ambulance response time is 6.9 minutes.

Gary Ellis, from CE Safety, said: “A person’s chance of surviving an out-of-hospital cardiac arrest decreases by an estimated 10% with every passing minute. And a person’s chance of surviving cardiac arrest in a work environment goes from 1-5% if given CPR alone, to between 49-75% if given CPR and an AED is used quickly.

“The numbers speak for themselves. Half of all out-of-hospital cardiac arrests are witnessed by a bystander. It is vital that we not only see greater access to defibrillators around the UK, but that we train as many people as possible in both work and public environments in how to handle a defibrillator confidently and effectively. In emergency situations they are literally life savers.”

Gary Ellis hosts AED first aid at work training courses around the UK. Click here for more information.


If you’re thinking about buying a defibrillator, visit:

  • The British Heart Foundation funds many purchases intended for public access. Here is the criteria for applying.
  • If you buy a public access defibrillator, don’t forget to register your AED here