What are they?
An Automated External Defibrillator (AED) is a life-saving device that is used to give a controlled electric shock in some cases of cardiac arrest.
When and how are they used?
In the UK approximately 60,000 people sustain cardiac arrest outside hospital and are treated by emergency medical services (EMS) each year. Defibrillation is well established as the only effective therapy for certain cardiac arrests (approximately 59% – 65% of cases). If defibrillation is delivered promptly, initial survival rates as high as 75% have been reported.
The chances of successful defibrillation decline at a rate of about 10-20% with each minute of delay. It should be recognised however that CPR (combined chest compression and rescue breathing or chest compressions alone) will help to maintain a shockable rhythm until a defibrillator arrives but is not a definitive treatment.
Defibrillation is not however used in all cases of cardiac arrest, even if available immediately, an AED would not be of use in 25% – 30% of heart disturbances caused by cardiac arrest, and CPR is the appropriate treatment. CPR should be commenced in all cases of cardiac arrest and the AED applied.
The AED will analyse the heart rhythm and will advise on whether defibrillation is advised. In just under a 1/3 of cases, defibrillation is not advised but CPR should be continued.
AED’s are commonplace in most public leisure facilities and educational leisure establishments.
Therefore, as part of your Emergency Action Plan you should know where the AED is located in the facility you are using.
* Cardiac arrest is totally different from a heart attack. A cardiac arrest happens when your heart stops pumping blood around your body. As a result you will be unconscious and won’t be breathing normally. Immediate cardiopulmonary resuscitation (CPR) and defibrillation is needed to have any chance of survival. The average age of a cardiac arrest in the UK is between 35-44 yrs old.
St. Johns Ambulance have provided some commonly asked questions about AED’s:
Q: What is an AED?
A: An AED is a sophisticated, reliable, safe, computerised device that delivers electric shocks to a casualty in cardiac arrest when the ECG rhythm is one that is likely to respond to a shock. Simplicity of operation is a key feature: controls are kept to a minimum, ‘voice and visual prompts’ guide rescuers. Modern AEDs are suitable for use by both emergency first aider as well as healthcare professionals. All AEDs analyse the casualty’s ECG rhythm and determine the need for a shock. The semi-automatic AED indicates the need for a shock, which is delivered by the rescuer, while the fully automatic AED administers the shock without the need for intervention by the rescuer, semi-automatic AEDs with manual override have the facility to enable the operator (normally a healthcare professional) to override the device and deliver a shock manually, independently of prompts.
Q: Are AEDs easy to use?
A: It is very easy to use an AED. You turn on the device (some devices turn on automatically when the lid is opened), and there are clear and concise ‘voice prompts’ advising you exactly what to every step of the way (both CPR and defibrillation). Most of our AEDs can be used by an emergency first aider or layperson with minimum training, although we would recommend either a fully automatic or semi-automatic device in these circumstances.
Q: Do I have to be trained to use an AED?
A: The 2010 Resuscitation Council (UK) guidelines still advise training for AED operators but state that in an emergency you do not have to be trained to use an AED; in short it is better to use it than not, even if a trained operator is not available. All our AEDs have step-by-step voice prompts, which explain exactly what steps to take to administer both shocks and CPR – however we understand that using an AED could be a daunting experience and that is why we offer a FREE AED (incorporating CPR) training course place with every AED purchased from us.
Q: Can AEDs be used on children as well as adults?
A: Yes, standard AED pads are suitable for use on children older than 8 years. Special infant/child pads that attenuate the current delivered during defibrillation, should be used on children aged between 1 and 8 years if they are available; however, in an emergency, if an AED with adult pads is the only device available, its use should be considered. The use of an AED is not recommended on children aged less than 1 year.
Q: Has anyone been sued in the UK for using an AED on a casualty who did not recover?
A: As far as we are aware no one in the UK has been successfully sued for using an AED on a cardiac arrest casualty and failing to revive the casualty.
Q: What if I use an AED and make things worse by shocking someone that does not need shocking?
A: It is impossible to shock someone that does not require it, as the device only shocks if the person is in fibrillation. You should consider that an AED is only used on someone that is not breathing; in reality you cannot make this condition worse.
Q: Are AEDs dangerous unless used by a medical professional?
A: No; anyone can safely use an AED even the untrained layperson or an emergency first aider who, witnesses a cardiac arrest, or who are nearby and can respond more quickly than the ambulance service. The minutes saved are crucial and this strategy has been responsible for saving many lives. Research shows that for every minute that the first shock is delayed, the chances of the patients survival diminishes by 10%. The Resuscitation Council (UK) advises the administration of a defibrillatory shock should not be delayed while waiting for more highly trained personnel to arrive. The same principle should apply to individuals whose certified period of qualification has expired.