Of all of the problems that you may have to deal with, Cardiac Arrest is by far the most important.
There are around 60,000 cases of suspected out of hospital cardiac arrest (OOHCA) in the UK each year, with approximately half of these receiving a resuscitation attempt from the Ambulance Service.
The average survival rate from OOHCA in the UK is poor when compared to some other countries. If more people know what to do when someone collapses, it could save thousands of lives each year.
The Chain of Survival
The Chain of Survival is a series of steps that need to be in place to maximise the chance of survival.
Let's look at each of these first three links in more detail, as these are the ones relevant to a first aider.
Link 1 - Early Recognition and Call for Help
The majority of cases of cardiac arrest in adults happen as a result of a big heart attack. If we can recognise a heart attack, then hopefully we can get help before it becomes a cardiac arrest. If anyone has chest pain or tightness, call 999 immediately. Find out more in this post about chest pain.
We also need to be able to recognise cardiac arrest, so that we can give the correct treatment. If someone has collapsed and is not breathing, they are in cardiac arrest.
However, about half of people in cardiac arrest will be doing something called 'agonal breathing'. Watch this video From Herlev Hospital in Denmark to find out more.
If someone has collapsed and is not breathing, or is not breathing normally, they are in cardiac arrest.
If you recognise someone in cardiac arrest:
Call 999 immediately - they will tell you what to do
Send someone to get a defibrillator - the controller will tell you where the nearest one is if you don't know
Start CPR - putting your phone on speaker helps
Link 2 - Early CPR
CPR involves taking over the function of the heart and lungs through chest compressions and ventilations (sometimes called rescue breaths).
Start with chest compressions.
The ratio of chest compressions to ventilations is 30:2 for both adults and children.
Chest Compressions
Doing great chest compressions will circulate the blood and generate blood pressure. Both are necessary to keep the person's brain oxygenated and alive.
Therefore, immediate, high quality chest compressions with minimal interruptions are the backbone of any resuscitation attempt. Move the person on to their back on a hard surface.
To do great chest compressions, do the following:
Position your hands in the centre of their chest
Push down 5-6cm in an adult, or 1/3rd of the depth of the chest in a child
Release after each compression (to allow the heart to refill with blood)
Repeat at approximately 2 per second
Doing chest compressions is tiring. If possible, change the person doing chest compressions at least every 2 minutes to maintain quality. Minimise any interruption to compressions by swapping when using the defibrillator, or when doing ventilations.
If you're doing chest compressions, count out loud so that you and anyone else present know how many have been given. This will help minimise the interruption when ventilating the patient. Don't worry if you lose count, just guess where you are and carry on.
It's possible that you might hear and/or feel an occasional rib 'break' during chest compressions. Don't worry, this is normal and tells you you're pushing hard enough.
Ventilations (or Rescue Breaths)
Ventilations are critical to get oxygen in to the patient, and so keep their brain alive. How you ventilate the patient depends on the equipment you have, but it will involve a version of 'mouth-to-mouth'.
There is a risk of cross infection when giving mouth-to-mouth, particularly if the person has been sick, or has saliva or blood around their mouth. If you have it available, you may wish to use a face shield or pocket mask to reduce the risk of infection.
If you are not comfortable doing ventilations, doing compression only CPR is better than not doing anything at all.
After 30 chest compressions, aim for two effective ventilations.
Try to do these briskly so that you don't significantly interrupt chest compressions and allow the blood pressure to drop.
To give an effective ventilation:
Open the airway by tipping their head back
Pinch the nose shut
Seal your lips over their mouth
Breathe in to them until the chest begins to rise - no more
Release to allow the air to come back out - maintain the airway
Repeat once
If one or both attempts fail, go back to chest compressions, and try again after 30 more compressions. Think about why it didn't work and change it - make sure you tip the head right back.
If vomit comes out of a person while doing CPR, stop what you are doing and turn them on their side to tip the vomit out, then continue.
Keep repeating 30 compressions and 2 ventilations.
Link 3 - Early Defibrillation
The cause of OOHCA for the majority of people is a heart attack, and in this case the heart will often 'fibrillate' in the early stages of Cardiac Arrest.
Fibrillation is caused by chaotic electrical activity in the heart muscle, which stops it from being an effective mechanical pump.
In order to stop fibrillation, a shock must be passed across the heart using a defibrillator. For the first aider, this will usually be a public access defibrillator (or AED), known as a PAD. PADs can be found in many public places and the 999 control room should be able to tell you where the nearest one is if you don't know.
PADs are usually in a locked box to stop them being stollen. To open it, follow the instructions on the box - call 999 and tell them the location code written on the box. They will tell you the code to the 'push button' lock.
A defibrillator will assess the electrical rhythm of the person's heart. If it detects fibrillation, it will charge itself up and then allow a shock to be delivered to the patient. Some AEDs are 'semi-automatic' and require someone to press a button to deliver a shock, but others are fully automatic and will deliver a shock after giving an audible warning.
The shock will stop the electrical activity of the heart, in the hope that it restarts in a normal rhythm. However, this is not always the case and even if a normal rhythm is achieved, it may soon deteriorate in to some other rhythm.
If the person has any other rhythm than fibrillation, it will not shock.
Use the AED as soon as it arrives. If there is more than rescuer present, continue chest compressions whilst the pads are being placed.
To use a defibrillator:
Open it - this will turn the defibrillator on and it will then tell you what to do
Attach the pads to their bare chest (quickly dry and/or shave if necessary)
Do not touch the person while analysing
Deliver shock if necessary - ensure no-one is touching the patient
Continue CPR after shock delivered, or if no shock is necessary
The defibrillator will then allow you to do CPR for a further 2 minutes. Then it will say 'do not touch the patient' while it analyses (and may shock) again. It will repeat this process every 2 minutes.
Stopping CPR
Only stop a resuscitation attempt if:
The ambulance service take over
You become exhausted or are at risk from a hazard
The person is definitely waking up or is breathing normally
If the person is definitely waking up or breathing normally you should:
Stop CPR
Turn off the defibrillator but leave the pads attached
Manage the person's airway if necessary
Be prepared to re-start CPR and defibrillation if the person stops breathing
Modifications
If possible, the following modifications should be made to the protocol. If the modifications cannot be recalled, use the standard protocol.
Children and Infants
Children (defined as those who have not yet reached puberty) and infants (under 1 year old) tend to go in to Cardiac Arrest due to respiratory causes, rather than heart disease as with most adults. Therefore, the following modifications are made:
Start with 5 ventilations before compressions
Use less force to do compressions - 1 hand for a child or 2 fingers for an infant will do
Use paediatric AED pads or use the selector switch on the AED for children (usually under 7/8 years old) - if none available use adult pads
Use the front and back pad positions
Drowning
If the person has gone in to cardiac arrest due to drowning, the following modifications are made:
Start with 5 ventilations before starting compressions
Be prepared for to clear vomit or frothy secretions from the mouth
Trauma
If the person is in traumatic cardiac arrest, it is unknown whether it is better to start CPR or not. Guidelines still state that CPR should be started, but that chest compressions should be 'de-emphasised'.
Follow the normal trauma primary survey. Identify and stop any catastrophic bleeding, manage the airway and then check for breathing. If they are unconscious and not breathing, or not breathing normally, start CPR. If they start bleeding significantly when you start compressions, get someone to deal with this whilst carrying on CPR.
Follow Up
Doing CPR can be a traumatic experience, particularly if it is someone you know, or is a child.
If you think you are struggling to process the experience, ask for help from your employer or a healthcare professional such as your GP.
Knowledge Check
Now check your knowledge by having a go at our 1-minute cardiac arrest quiz...
Summary
In summary, you can significantly increase the chance of survival in out of hospital cardiac arrest.
If someone has collapsed and is not breathing, or is not breathing normally...
Call 999
Send someone for a defibrillator
Start CPR (30 compressions to 2 ventilations)
Attach the defibrillator as soon as it arrives
Follow the voice prompts
Keep going until they wake up, start breathing or the ambulance service take over.
If you'd like to know more about how to maximise the chances of survival in cardiac arrest, why not book one of our First Aid Courses.