First Aid Certificate Training and Courses

The Chain of Survival

The Chain of Survival

The Chain of Survival is the term applied to a sequence of actions that, when put into motion, reduce the mortality associated with cardiac arrest. While each action in the chain is unlikely on its own to revive a casualty, when all actions are effectively used together they can improve the outcome for the casualty.

Sudden cardiac arrest is the unexpected collapse of a casualty whose heart has stopped. Cardiac arrest occurs suddenly due to a disturbance in the electrical signals of the heart and is closely linked with sudden chest pain. It is estimated that more than 95% of sudden cardiac arrest casualties die before reaching hospital as the casualty has only minutes from the time of collapse until death.

If all four links in the Chain of Survival are strong the chance of survival for a sudden cardiac arrest casualty can rise from 5% to as high 70%.

Early Access

The first link in the Chain of Survival is the call to emergency services. An immediate call to 000 for an ambulance is crucial; a delay of only a few minutes could be fatal. By quickly recognising a medical emergency you can save a life as it means Early Advanced Cardiac Life Support can be started as soon as possible.

Early Cardiopulmonary Resuscitation (CPR)

CPR is the second link in the Chain of Survival; it is the link that can buy life-saving time between the first link (Early Access to emergency care) and the third link (Early Defibrillation).

During sudden cardiac arrest (SCA), the heart twitches irregularly most often due to ventricular fibrillation (VF) and cannot pump oxygenated blood efficiently to the brain, lungs, and other organs. The casualty quickly stops breathing and loses consciousness.
However, prompt CPR may help to sustain life during VF. Mouth-to-mouth breathing and chest compressions help oxygenated blood flow to the casualty’s brain and heart, until defibrillation can attempt to restore normal heart pumping.
Although CPR can sustain life for a short time, it must be followed within minutes by the third link, Early Defibrillation. Only when combined with Early Defibrillation and Early Advanced Cardiac Life Support can CPR significantly increase a sudden cardiac arrest casualty’s chance for long-term survival.

Early Defibrillation (A. E. D)

If CPR is given within 4 minutes and defibrillation within 8-12 minutes, the chance of survival is significantly improved.

Most sudden cardiac arrest casualties are in VF or VT. Defibrillation, the delivery of an electrical shock to the heart muscle, can restore normal heart function if it occurs within minutes of sudden cardiac arrest onset.


Early Advanced Cardiac Life Support

The fourth link in the Chain of Survival is Early Cardiac Advanced Life Support. Paramedics and other highly trained emergency services personnel provide this care, which can include basic life support, defibrillation, administration of cardiac drugs, and the insertion of endotracheal breathing tubes. This type of advanced care can help the heart in VF respond to defibrillation and maintain a normal rhythm after successful defibrillation.

Paramedics monitor the casualty closely on the way to the hospital, where more definitive assessments can be made.

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