What is all this about AEDs?

Disclaimer: We are not medical experts, what is written below are our opinions and understanding. It is STRONGLY recommended you seek advice from your Ambulance Service and/or other medical professionals.

Disclaimer: NEVER perform CPR or use an AED on someone unless it is a medical emergency.

We have been asked several questions over the last month or so, the bulk of which relate to Automated External Defibrillator’s (AED). So we have put the following together to try and answer some of those questions.


In any medical emergency getting help to the casualty as quickly as possible is crucial. Heartstart Thatcham, which is a non-profit group, have been teaching Emergency Life Support (ELS) skills to the public, for free since 2013. The idea is that in an emergency anyone who has done the course will have the skills to cope until professional help arrives. This is the first step in getting help to a casualty as fast as possible. However in some instances, such as cardiac arrest, additional equipment can significantly improve the chances of survival for a casualty. The Heartstart Thatcham team are working with locals to get more AEDs place around Thatcham and Newbury for use by the public when a casualty is in cardiac arrest.

What is a Cardiac Arrest?

A cardiac arrest is where the heart has stopped pumping blood around the body, it is an electrical problem with the heart. This is different to a heart attack, which is a circulatory (plumbing) problem. When someone goes into cardiac arrest blood is no longer being pumped around the body. It is vital therefore that Cardio Pulmonary Resuscitation (CPR) is started as soon as possible to keep blood and oxygen flowing around the body. There are different types of cardiac arrest, some though can be corrected with an application of an electric shock and this is where the defibrillator, an AED, comes in.

What is an AED?

An AED is a defibrillator, specifically it is a simple and easy to use device designed to be used by the bystander on someone who is in cardiac arrest. The devices are designed to be used by anyone and thus require no training. The device, once turned on, will tell you by voice prompts, and in some cases a display, what to do and where to place any pads on the casualty. Once the pads are in place it will measure the electrical output of the heart. If a shock is required it will then ask you to press a button to shock the casualty. The devices will not shock a casualty unless a shock is required and so cannot be misused or misapplied.

Trainees placing AED pads on a casualty and ensuring area is clear prior to delivering a shock.

The way this works in reality is; Assume you have seen someone collapse to the floor and you are unable to get a response from him or her. To start with you would not know the person is in cardiac arrest so you call 999. If the casualty is not breathing, the operator will get you to check if you have not done so, you would be instructed to start CPR and someone told to go and get an AED if there is one available nearby. Once an AED is on scene you can then follow the instructions of the AED or get the operator on the phone to walk you through the process. The crucial step here and in any medical emergency situation is dialing 999 as soon as possible.

Why the need for CPR and AEDs?

Simply put, to save lives. To put this in some context there are in excess of 60,000 (BHF) cardiac arrests every year in the UK that happen outside of the hospital environment. Out of that only 10% (BHF) will survive, that is only 6,000 out of the 60,000. In addition to this there is the fact that whilst someone is in cardiac arrest their chance of survival decreases by about 10% for every minute that passes without CPR and/or defibrillation. Getting help and starting CPR immediately is a priority and where available getting an AED to the scene can significantly improve the survival rates, in some cases the chances of survival raise up to 75% (BHF).

Where to place AEDs?

Every minute counts whilst someone is in cardiac arrest so the more places these devices, AEDs, can be placed the better. In reality though there are constraints, such as where they can be physically placed and cost. Many heart health organisations suggest placing where people are physically exerting themselves, a school, a leisure centre, a dentist, a business, a doctors surgery, a golf course, etc. But also remember Cardiac Arrest can happen anywhere and without warning.

It is worth noting (as noted on 10th June 2014) are that the Resuscitation Council (UK) and the British Heart Foundation recommend that Public AEDs are available without restriction. Some bodies (including Kansas City First Aid) state, or imply, an AED ideally should ideally be no more than 100m away if someone is to retrieve it on foot. Whilst having AED spaced close together, 200m apart, would be fantastic and ideal, in reality it is unlikely to happen.

We suggest if you are planning on installing an AED in your community then you speak to your local Ambulance Service.

What are we doing?

Firstly there is our ongoing course in Emergency Life Support that continues to teach the basic principles of first aid. But in addition we are working with a number of groups in and around Thatcham and Newbury to place more AEDs that are accessible to the public, Public access Defibrillators (PADs). This includes obtaining permission to put devices onto buildings and fundraising. A further initiative is our Phones2AEDs campaign, where we are collecting old mobile phones and for a given number exchanging them for AEDs. This will then be placed in the community. We are more than happy to hear from anyone who wants to get involved (Thatcham, Newbury, Cold Ash, Greenham, anywhere...), make a donation, or just wants to know more.