This statement has been reviewed and updated by the Community and Ambulance Resuscitation (CARe) Subcommittee within Resuscitation Council UK.
When someone sustains a sudden cardiac arrest, prompt action by someone nearby offers their only chance of survival. An immediate 999 call for an ambulance and starting cardiopulmonary resuscitation (CPR) promptly are essential. Most people who survive will also require a shock from a defibrillator to correct a chaotic heart rhythm.
The earlier that shock is given, the better the person’s chance of survival. Studies have shown that a shock given within 3 minutes of cardiac arrest provides the best chance of survival and that even one minute of further delay reduces that chance substantially. In most situations, ambulance services cannot reach the scene of a cardiac arrest and deliver a shock within 3 minutes.
For that reason there are increasing numbers of automated defibrillators available for use by members of the public. They are referred to as ‘public access defibrillators’. Using a public access defibrillator is simple - just switch the device on and follow the spoken instructions. They can be used effectively and safely by people who have had no prior training.
Further studies have confirmed that immediate delivery of CPR combined with the early use of an automated external defibrillator by members of the public gives a person in cardiac arrest the best chance of survival.
Cabinets for public access defibrillators
Public access defibrillators are usually kept in cabinets in prominent public locations with appropriate signage to help people to locate them. There has been a long-running debate about whether these cabinets should be unlocked with the defibrillator openly accessible, or whether they should be locked and therefore more secure. Many locked cabinets require a numerical code to unlock the door. The ambulance service will give this code to the person who makes the initial 999 call, once they have confirmed that they are dealing with a cardiac arrest. Other cabinets can be unlocked remotely from the ambulance control centre in this situation.
Measures other than locks may be used to protect a defibrillator in an unlocked cabinet (see below) while advances in technology may lead to other options in the future.
Advantages and disadvantages of unlocked and locked cabinets
The priority is to apply an automated defibrillator to the person in cardiac arrest with the absolute minimum of delay. Unlocked cabinets allow immediate access to a defibrillator in a situation where seconds count. There will inevitably be a delay where a cabinet has to be unlocked to access the device. A person who collects a public access defibrillator from a locked cabinet (while other people call 999 and start CPR) will have to call 999 themselves before they can get the defibrillator, and take it to where it is needed. This wastes valuable time and requires an extra call to the ambulance service that may well be busy responding to many other calls.
There is concern that a defibrillator in an unlocked cabinet may be stolen or tampered with, making it unavailable or of no use to a person in cardiac arrest. Despite widespread use of unlocked cabinets, experience to date has shown that instances of theft and vandalism of such defibrillators are relatively uncommon.
Locking a cabinet is no guarantee that a defibrillator will not be stolen or vandalised. A locked cabinet implies that the defibrillator is sufficiently valuable to be worth stealing. Reports from ambulance services and other sources provide no evidence that public access defibrillators in locked cabinets are less likely to be stolen or vandalised.
Other crime prevention measures may reduce the risk of theft or tampering with a public access defibrillator. These include siting the cabinet in a public place where it is supervised or covered by closed-circuit television surveillance. The use of tracking devices in defibrillators will immediately indicate their removal from the cabinet and their whereabouts will subsequently be traceable.
Lockable cabinets inevitably introduce delay in obtaining a defibrillator and applying it to a person in cardiac arrest. A person who knows where the nearest public access defibrillator is and runs straight to the cabinet to fetch it (whilst other people call 999 and start CPR) will have to call 999 themselves before they can get the defibrillator and take it to where it is needed. This wastes valuable time in getting it to the person in cardiac arrest and requires an extra call to an ambulance service that has to respond promptly to many other calls.
Other crime prevention measures may reduce the risk of theft and tampering with a public access defibrillator. These might include siting the cabinet in a public place that is covered by closed-circuit television surveillance, and/or use of tracking devices in defibrillators, so that their removal from the cabinet is known about immediately and their whereabouts are traceable, or other clearly advertised measures that will discourage criminal interference.
Other measures clearly advertised alongside the cabinet will also discourage criminal interference. Such a notice might include the information that the defibrillator is vital lifesaving equipment and that to remove it may cost someone's life - and that might be a friend or relative. It can be stated very clearly that the devices are all individually recognisable and traceable and have no other use or inherent value.
Another factor to consider is cost. A defibrillator and lockable cabinet or a defibrillator with additional technology (such as remote tracking) costs substantially more than a simple cabinet and straightforward defibrillator, respectively.
The Circuit is a national network that links public access defibrillators to ambulance service control centres so that their whereabouts are known. It is important that everyone who owns an AED intended for public use registers their device with their local ambulance service as this enables ambulance call-takers to direct people to the nearest defibrillator. There are other advantages as The Circuit will send out regular reminds about the upkeep and maintenance of the defibrillator. Further information is available at https://www.thecircuit.uk.
In most cases public access defibrillators will be available for use at all times and registration with The Circuit will be straightforward. In other circumstances, the defibrillator may not be constantly accessible, for example at a school that is closed at weekends or holiday times, or in a shop that is closed at night. Such defibrillators should still be registered with The Circuit and their hours of availability made clear to the ambulance service.
Where circumstances allow, defibrillators should be placed in openly accessible (unlocked) cabinets that allow immediate access in an emergency. A decision to place a public access defibrillator in a locked cabinet should be made only on the basis of careful risk assessment in that specific location.
Liaison and collaboration with the local ambulance service is crucial to the success of any public access defibrillator scheme, and it is important to take their advice on the type of defibrillator and cabinet to install. It is also recommended that advice is sought from the local police force about the risks of theft or vandalism and the security measures that will minimise these without making the defibrillator inaccessible or creating avoidable delay in access when it is needed.
Reviewed and updated September 2021