The Chain of Survival concerns the four steps to be taken should you find someone who is suffering from cardiac arrest. The UK sees more than 30,000 Out-of-Hospital Cardiac Arrests (OHCA) each year in which attempts to resuscitate are made by the emergency medical services. However, just 1 in 10 victims survive an OHCA in the UK.
Early prevention and recognition is, therefore, a crucial stage in an attempt to save someone from cardiac arrest. To recognise a cardiac arrest, you should first be aware of what a cardiac arrest is and what it looks like, as well as how it differs from a heart attack.
The fundamental difference between a cardiac arrest and a heart attack is:
- Cardiac arrest occurs when the heart stops pumping blood around the body, causing the person to stop breathing normally.
- Whereas, heart attacks happen as a result of coronary heart disease (CHD), in which a blockage in one of the coronary arteries, due to buildup of fatty acids called atheroma, means that the heart muscle fails to receive its vital blood supply and the person no longer gets enough oxygen.
What should you do if someone suffers a cardiac arrest?
Cardiac arrest is often a consequence of a heart attack as a result of a dangerous heart rhythm. In the cases of both cardiac arrests and heart attacks, the emergency services must call 999 immediately. As they are different conditions, they require different treatment and so the Chain of Survival only concerns situations involving cardiac arrest.
Follow these four steps to give you the best chance of saving someone suffering from an out-of-hospital cardiac arrest:
1) Early Prevention & Recognition
To decide upon the course of action, you must first determine if the person is having a heart attack or cardiac arrest. Someone experiencing a heart attack will have chest pain or discomfort, but crucially will still be breathing and conscious. In this case, you should call 999 for an ambulance immediately, then remain with the victim and get them to remain calm whilst sitting in a comfortable position. If you have an aspirin accessible, you should give them an adult tablet of aspirin (300 mg), as long as the person is not allergic to aspirin, whilst you wait for the emergency services to arrive.
Cardiac arrest symptoms present themselves in someone who is unconscious, unresponsive, and not breathing, or breathing abnormally. In this situation, you should also call for an ambulance straight away. The ambulance call handler will then ask questions to help you identify if the person is suffering from cardiac arrest.
Causes of cardiac arrest include ventricular fibrillation (VF), a heart attack, cardiomyopathy, congenital heart disease, hypoxia and a drug overdose. Knowledge of whether the person has experienced any of these conditions before may help you detect cardiac arrest. Furthermore, electrocution can also cause cardiac arrest and so checking your surroundings as you approach the person is important for your own health.
2) Early CPR
To increase the chances of survival for the victim, cardiopulmonary resuscitation (CPR) should be carried out whilst involves two important skills: chest compressions and rescue breaths.
Chest compressions are used to help pump blood around the body. To carry out chest compressions, place the heel of your hand in the centre of the person's chest and clasp your hands together, placing one hand on top of the other. You should then press down hard (5 to 6cm or 2 to 2.5 inches) and fast (100-120 compressions per minute) to the rhythm of 'Stayin' Alive' or 'Baby Shark'.
Rescue breaths should then be used to provide the person oxygen to help them breathe again. For every 30 chest compressions, it is then recommended to give 2 rescue breaths. If rescue breaths are not possible, for instance, if the person has blood or vomit on or in their mouth, or you have not been trained in giving CPR and, therefore, rescue breaths, continue with just chest compressions.
3) Early Defibrillation
The ambulance call handler should help you locate the nearest defibrillator (also known as an AED or Automated External Defibrillator) which, once turned on, provides the user with step-by-step audio and/or visual instructions on how to use it. You will need to check that the AED is operable – the device performs regular self-tests and should have an on-screen indicator, such as a green light, to show that it is safe to use. You must remove the victim's top in order to place the AED's pads on their chest, ensuring that it is safe for the electric shocks to be delivered to the patient. For example, if the patient is wet or lying in water then you will need to move them away from the water and dry their chest before using the AED. Furthermore, ethical issues can influence whether you should use a defibrillator or not, for instance, if the victim has a DNR ‘Do Not Resuscitate’ band or tattoo.
Using an AED within the first 3 minutes of sudden cardiac arrest can increase survival rates by over 80%. If there is not a defibrillator present, you should continue to give CPR until the emergency services arrive.
An AED is a portable electronic device that uses electrical defibrillation to treat somebody experiencing cardiac arrest, helping to regain the patient’s regular heart rhythm or restart the patient’s heart altogether.
4) Post-Resuscitation Care
Continuous CPR and defibrillation should be maintained on the cardiac arrest victim until they regain a normal breathing rhythm, or until the emergency services arrive to take over and take the person to the hospital.
Understanding the Chain of Survival and its importance in potentially saving the life of someone experiencing cardiac arrest, through resuscitation and defibrillation, really can be the difference between life or death. Please note that the Chain of Survival above is only for adults suffering cardiac arrest. The procedure, such as how CPR is carried out, differs for children and infants. First aid for children and infants is covered in our Paediatric First Aid training course.
We offer multiple other training courses that teach learners the fundamentals of first aid, resuscitation and the use of AED machines, including Automated External Defibrillation (AED), First Aid Awareness and Choking Prevention and Resuscitation Awareness. All these courses and more are available on our First Aid training page.