How to Perform Adult CPR and Use a Defibrillator (AED)

Image of CPR + Defibrillator

January 31, 2022

If a casualty is unresponsive AND is NOT breathing effectively, the statistical likelihood is that they have suffered a Cardiac Arrest.

Over 30,000 people suffer an ‘Out of Hospital Cardiac Arrest’ every year in the UK. Every minute without CPR and defibrillation reduces the chances of survival by up to 10%. Performing CPR can more than double the chances of survival, in some cases.

A defibrillator in a public place is usually mounted on the outside of the building or inside if it’s a business. Most supermarkets have them inside. They are marked with a large green and white sign.

Defibrillators are very easy to use. Once turned on, using the green button, they talk you through the steps required. Once attached to casualty, they continually analyse the heart and will advise you when to press the orange button to deliver a shock if required.

Some important things to note:

  • Shouting for help and getting someone else to go and get the defibrillator as well as making that phone call really helps the first aider, as you can start CPR straight away.
  • Knowing where your nearest defibrillator is located will greatly improve their chances of survival.

The steps in assessing the situation and starting CPR on a non-breathing casualty:

  1. When you come across a casualty, stop and assess for danger. Do not put yourself at risk. Remove or minimise the danger e.g. traffic, horse, mountain bikers on the trail etc.
  2. When the scene is safe, put your first aid/ surgical gloves on if you have them with you and approach the casualty.
  3. Call out to them ” Hello my name is _________. I’m a first aider / here to help. Can you hear me?”
  4. Tell them, in a good voice, “Open your eyes. I’m going to put my hands on your shoulders. Open your eyes if you can feel that”
  5. If there is no response – shout for help, loudly.
  6. Next, you need to check their airway is clear. Open the casualty’s airway by tilting back their head slightly and lifting their chin.
  7. Now check their breathing. Look down to their chest or belly and see if they are breathing. Count for 10 seconds. If they’re not breathing effectively…..
  8. Now – phone 999/112 and tell them your location and that you have an unresponsive, non-breathing casualty and that you are going to start CPR. The switchboard may tell you where the nearest defibrillator is.
  9. If someone has come as a response to your help cries, get them to make the phone call and/or go to get the defibrillator.

Starting CPR:

  1. Interlock your fingers, one hand above the other. Using the heel of your hand, place your hands in the centre of the casualty’s chest.
  2. Keep your arms straight and your shoulders in line above your hands.
  3. Do 30 chest compressions, 5-6 centimetres deep into the chest.
  4. Count out loud 1-30 at a rate of about 2 per second. Or think of the rhythm of the Bee Gees song ‘Ah Ah Ah Ah Stayin Alive, Stayin Alive…’ as a guide to the rate of compressions.
  5. Then do 2 rescue breaths. 2 good breaths into their mouth, using a face shield if available. Look down to their chest after each breath to see if their chest is rising.
  6. Then return to do 30 more chest compressions.
  7. Continue doing 30:2 chest compressions to rescue breaths. until the AED arrives……..

The steps in using an AED / defibrillator:

  1. When the AED is being set up by someone else, DO NOT stop doing CPR. It’s easy to get distracted when you’re telling them what to do or how to set it up.
  2. Turn the defibrillator on by pressing the large green button. You may need to hold it down for a second or two.
  3. Once you turn the defibrillator on, it talks to you and takes you through step by step
  4. It will say “Attach pads to patient’s bare chest”. Top right of the chest and lower left of the rib cage areas – as per the pictures on the pads. The pads have sticky backs which need to be removed before attaching. The bare chest can be wiped dry or shaved where required – there is usually a razor and towel in the AED bag/box. Bras do not need to be removed or cut
  5. It will then say ” Plugin connector next to flashing light”. These are usually yellow like the plug connector at the end of the sticky pad leads.
  6. It will then say “Analysing heart rhythm – do not touch the patient“. Stop doing CPR at this point so the defibrillator can analyse the patient’s heart rhythm without you doing chest compressions on them.
  7. After analysing, it may say “Shock advised…… Charging………..Stay clear of patient……Do not touch the patient…..Deliver shock now…press the orange button now.” Press the orange button with the electrical symbol on it.
  8. Aftershock is applied, it will usually say “Begin CPR” and it will emit a beeping sound which is the correct rhythm for doing chest compressions.
  9. After analysing, it may alternatively say “Shock not advised. If required, begin CPR“. This does not mean the patient is improving or that their heart has started again. It means the rhythm it detected would not benefit from a shock.
  10. Every 2 minutes the defibrillator will go through this sequence again to re-analyse the heart rhythm.
  11. Keep doing CPR at a rate of 30 chest compressions to 2 rescue breaths AND follow the instructions from the defibrillator until the ambulance arrives and the paramedics tell you to stop.

At some stage, you may want to share the workload of doing CPR as it can be very physically tiring. It is an easy technique to show someone. If someone helps you, give them tips on their technique and lots of praise for stepping in to help.

Using a defibrillator is an essential skill in first aid these days. It is now part of the standard syllabus for all first aid courses.

If a defibrillator is available – use it. It is a lifesaver!

The pads in a defibrillator pack will be marked for adult or child use. Images on the pads show you where to put them.

Frequently asked questions:

How easy is it to use an AED/defibrillator?

AEDs or defibrillators are automated devices that talk you through, step by step, how to use them. They have sticky pads with leads attached. You put the sticky pads onto the casualty and then plug the leads into the defibrillator. There are 2 buttons, a green one to turn it on and an orange to deliver a shock to a casualty. The machine will tell you when to use the orange button.

Can I kill someone with an AED/ defibrillator?

No. The defibrillator analyses the heart rhythm of the casualty and only advises you to press the shock button if the casualty would benefit from the shock. There are many different heart rhythms. Defibrillators are designed to analyse them and only deliver the shock where necessary.

The defibrillator says ” No shock advised”. Does this mean they’re getting better or their heart has started again?

No. It means the rhythm that the defibrillator detected is not going to benefit from a shock. The defibrillator WILL tell you to continue with CPR though.

How can I find out where my nearest defibrillator is?

In the UK, when you phone 999/112, they will tell you where your nearest defibrillator is according to their records. It is good to get to know where your nearest defibrillator is in your workplace, school, community and somewhere you visit regularly such as a leisure centre or shopping centre. Several sites list them. One of the most useful is although not all defibrillators are registered there – it is up to the owner of the defibrillator to register them. If you know of one locally, ask if they’ve registered it with The Circuit. It could save a life in your community!

Can you get a mobile defibrillator? One that I can take up a mountain, in my van or on a boat?

Yes, but they are heavy due to the battery size required. The battery also needs charging regularly. They exist though and battery technology is being improved all the time.

What is being developed in defibrillator technology now?

As with all things medical, improvements and changes occur based on either experience or research. Delivering defibrillators via drones to remote or dangerous locations is well advanced and maybe a reality very soon. Different languages are already included in defibrillators – you can choose which ones to have in your device based on your community or workplace need. Some defibrillators will count 1-30 out loud at the correct rate then tell you to do the rescue breaths.

Where can I buy a defibrillator?

We sell the Mediana HeartOn Defibrillator via our website. It is one of the most user-friendly & robust AEDs on the market. Click the button below to find out more.

Interested in learning more?

All of our first aid courses include practical training in CPR and practice using an AED.

This allows organisations to demonstrate best practices, and give all members of staff the confidence and competence to use a defibrillator if they have to.

Contact us to learn more about our range of courses.

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