All about defibrillators: what they are and how to use them.
Cardiac arrests can affect anyone at any time. 30,000 occur outside of hospitals across the UK each year. Currently less than 10% of these people experiencing cardiac arrests in the community survive…
With speedy emergency treatment, chances of survival shoot up by a whopping 80%.
Yet, terrifyingly, the average ambulance response time in an urban area is a full eleven minutes. In the rest of the UK, it’s around 8 minutes.
20% of out-of-hospital cardiac arrests happen in public places. If you suffer an arrest out and about, you would be reliant on the public’s ability to perform CPR and indeed the availability of a defibrillator.
CPR alone can double the chances of survival. When you use a defibrillator in addition to quality CPR, the odds of someone’s survival can jump from around 6% to 74% – an incredible difference.
Defibrillators are the brightly coloured boxes seen in supermarkets, tube, rail and bus stations, airports, some telephone boxes and other high traffic areas and public places.
How a defibrillator works:
An AED is an Automatic External Defibrillator – which means that it automatically detects if someone is in a shockable rhythm and it speaks to you, to tell you what to do.
Defibrillators do not jump start the heart like jump starting a car; they stop it like rebooting a computer. Ultimately this allows the individual heart cells to recharge simultaneously and the pacemaker in the heart to hopefully restart it in a normal rhythm.
The defibrillator administers a shock to stop the heart if it is in an abnormal but shockable rhythm. Enabling the heart’s own system to reboot and hopefully restart in sinus rhythm (normal beat).
AEDs are used in addition to CPR to save the lives of those suffering cardiac arrest.
Research has shown that deploying a defibrillator within 3–5 minutes of collapse can produce survival rates as high as 50–70%.
Where to find them
Automatic External Defibrillators (AEDs) are now easily accessible at numerous locations; train and tube stations, shopping centres, Dental and GP Practices, sports grounds, leisure centres and are available for the general public to use.
They can be semi-automatic (you still need to press the shock button when indicated) or fully automatic (the machine shocks automatically when a shock is advised).
Apps can help locate AEDs
These days there are apps that can be used to locate your nearest defibrillator, such as HeartStart, Pulse Point AED and Good Sam. Good Sam can locate nearest first responders to help too.
Why are they important?
Defibrillators are crucial to be able to have a chance of bringing someone back following a cardiac arrest. CPR helps circulate the blood, keeping the heart and brain sufficiently oxygenated, the AED is necessary to deliver the shock hopefully returning the heart to a viable rhythm.
Most sudden cardiac arrests result from ventricular fibrillation (VF). VF is a fast and erratic heart rhythm originating in the heart’s ventricles.
AEDs are only indicated for use if someone is unconscious and not breathing normally. An AED will only enable a shock to be given if someone is in a shockable rhythm – Ventricular Fibrillation or Ventricular Tachycardia, the machine will recognise the rhythm and advise whether or not a shock is advised.
Most importantly: you cannot shock someone if they don’t need it.
The sooner you recognise there is a problem, get help on the way, start CPR, use a defibrillator and transfer the casualty to advanced medical care, the better the outcome.
Currently, there is a new bill wending its way through parliament, with the aim of making defibrillators mandatory in public buildings. The Defibrillators Availability Bill was first read in Parliament in 2018 and not only recognises the need for AEDs in public places but also legislates for awareness and training to ensure people are ready to use them.
From September 2020, CPR will become a mandatory topic on the National Curriculum in England. Consequently, all young people in England should have learnt how to give CPR and use a defibrillator by the time they leave secondary school. We hope this will dramatically improve our survival rates from out of hospital cardiac arrests, to the same extent as it has in Denmark and other Scandinavian countries.
What do Employers Need to Know?
It is not compulsory for employers to purchase AEDs to comply with the Health and Safety (First Aid) regulations 1981. However, if your needs assessment identifies an AED need then it is recommended that staff should be fully trained in its use.
Hundreds of people are alive today entirely due to the prompt and appropriate use of a defibrillator. For every minute’s delay in deploying a defibrillator, the odds of survival reduce by about 10%.
Danger: Do not put yourself in danger
Response: if no response shout for help and if possible, get a bystander to call for an ambulance and locate a defibrillator if there is one.
Airway: Open the airway and check for breathing.
Breathing: If the casualty does not appear to be breathing normally and there are less than 2 breaths in a 10 second period you will need to start CPR
If you are on your own: call 999/112 and get the AED as quickly as possible if there is one nearby.
If you have help: get your bystander will need to let the emergency services know that the casualty is unconscious and not breathing. Meanwhile, you should bring the AED as quickly as possible. Continue CPR whilst waiting for the defibrillator.
To give effective CPR: push down 5-6 cms on the centre of the chest at a rate of about 2 compressions per second and ensure a release from pressure in between compressions, to enable the heart to refill. Give 30 compressions to 2 breaths.
Defibrillators are designed to be as easy as possible to use. They will tell you how to use them so even if you’ve never been trained you should try your hardest.
1. Firstly, activate it. Machines vary but this is usually done by opening the lid or pressing an obvious button.
2. If you aren’t alone, someone should continue, whilst the other attaches the leads to the AED (if necessary).
3. Dry the chest (and use the razor to shave if excessively hairy).
4. Peel the pad off the backing one at a time and place onto the dry chest according to the diagram on the packet.
5. Place one pad below the casualty’s right collar bone.
6. Position the other on the casualty’s left-hand side, over their lower ribs.
7. The AED will analyse the heart rhythm.
8. Stop CPR when instructed by the AED.
9. Ensure no one is touching the casualty.
If a shock is advised:
10. Check the whole length of the casualty to ensure no one is touching them.
11. Then shout loudly: ‘stand clear’.
12. Press the flashing shock button as directed (fully automated AEDs will do this automatically once a shock is advised).
13. Continue with CPR as directed.
14. Keep going with 30 compressions to 2 breaths.
15. Do not stop to check them unless they begin to regain consciousness and start breathing normally.
16. The machine will reassess their heart rhythm every 2 minutes and advise another shock if indicated.
If no shock is advised:
• Continue with CPR and follow prompts
• Keep going until help arrives, you are too exhausted to continue, or the casualty begins to regain consciousness and starts to breathe normally.
• The machine will reassess their heart rhythm every 2 minutes and advise a shock if indicated.
To give CPR: 30 compressions, then 2 rescue breaths. Repeat.
If there is more than one rescuer swap every couple of minutes.
Defibrillators dramatically improve a casualty’s chance of survival and are now widely available for the general public to use. However, we need far more in the community and work-places to be able to have the major improvements on survival from cardiac arrest that is seen in other countries such as Sweden.
Common myths about defibrillators and AEDs
Unfortunately there are many common misconceptions about defibrillators that prevent people from incorporating them in their mainstream first aid equipment:
“Defibrillators are complicated!” – MYTH
They couldn’t be much easier! The machine speaks to you and take you step by step through what you need to do to help save someone’s life. Furthermore, they are now available in so many public places and are easily accessible for the general public to grab and use as quickly as possible in a medical emergency. Additionally, you do not need specific training to use them.
“You have to be medically trained to use them!” – MYTH
Wrong! They are available for use by the general public. Ideally you would have received training in how to give the best CPR as this will make a huge difference and give them the best possible chance of survival. Using an AED is simple.
“You are jump starting the heart, like you do with a car!” – MYTH
Quite the reverse from jump-starting the heart, you are stopping the heart to allow the heart’s natural back-up system to take over and return it to normal sinus rhythm. Speed is of the essence as research has shown that the chances of survival for an out of hospital (community) cardiac arrest are only about 6%.
Thankfully, if you can get the pads onto the patient’s chest within 3 minutes and they are in a shockable rhythm, the chances of survival jump to 74%. This drops by 10% for every minute’s delay in using the machine.
“You could make things worse!” – MYTH
You cannot use a defibrillator if the casualty does not need it! It will not let you. So apply the pads, switch on the machine, you simply can’t do anything wrong. If someone is unconscious and not breathing, if you don’t do anything they will die.
“A defibrillator will always bring them back to life!” – MYTH
Sadly, this is not the case. There are many reasons why someone may experience a sudden cardiac arrest and it is not possible to resuscitate everyone. However, good quality CPR, prompt use of a defibrillator and swift transfer to professional medical care, will give them the best possible chance.
“You need to wait until the heart has stopped before using the machine!” – MYTH
Definitely not the case. The sooner you use the defibrillator the better their chances of survival.
“They are expensive!” – MYTH
You can now get a good quality defibrillator from us for less than £650.
“You can’t use them on children” – MYTH
If a child is unconscious and not breathing, you should use a defibrillator as quickly as possible in the same way as you would with an adult. You can use adult pads if you don’t have children’s ones available and would place one on the front of the chest and one on their back. For a child you start with 5 rescue breaths.
“You don’t need to do CPR if you are using a defibrillator” – MYTH
It is essential to be giving effective CPR alongside using the defibrillator. CPR circulates blood to the heart and brain. Without quality CPR it is highly unlikely the casualty will survive.
“Paramedics will always be there before I need to use it!” – MYTH
I am afraid that this is highly unlikely as our emergency services are hugely overstretched and they are not likely to be with you within 3 minutes.
Written by Emma Hammett for First Aid for Life
It is strongly advised that you attend a fully regulated Practical or Online First Aid course to understand what to do in a medical emergency. Please visit https://firstaidforlife.org.uk or call 0208 675 4036 for more information about our courses.
First Aid for Life is a multi-award-winning, fully regulated first aid training provider specialising in first aid and medical emergency training for Health Professionals. Our trainers are highly experienced medical, health and emergency services professionals who will tailor the training to your needs.
First Aid for life provides this information for guidance and it is not in any way a substitute for medical advice. First Aid for Life is not responsible or liable for any diagnosis made, or actions taken based on this information.