First Responders can play a valuable part in the Chain of Survival
Paramedics responding to a call

Chain of Survival

Thirty years ago, it was discovered that if a series of events took place, in a set sequence, a patient suffering from a sudden cardiac stood a greater chance of survival.

These events are now known as the 'Chain of Survival'.

The First Link in the Chain of Survival - Early Access to Emergency Care

When Sudden Cardiac Arrest strikes, an immediate 999 call is crucial; a delay of just a few minutes could prove fatal. By quickly recognizing a medical emergency, a bystander can help save a life. Could you recognize the symptoms of Sudden Cardiac Arrest?

They are:

  • Unresponsiveness
  • Loss of consciousness
  • Lack of pulse
  • Cessation of breathing


The Second Link in the Chain of Survival - Early CPR

CPR or Cardiopulmonary resuscitation 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, 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 victim quickly stops breathing and loses consciousness.

However, prompt CPR can help sustain life during VF. The mouth-to-mouth breathing and chest compressions help oxygenated blood flow to the person's brain and heart, until defibrillation can attempt to restore normal heart pumping.

The Third Link in the Chain of Survival - Early Defibrillation

Early defibrillation is the third and perhaps most significant link. Defibrillation, the delivery of an electrical shock to the heart muscle, can restore normal heart function if it occurs within minutes of SCA onset.

When CPR and defibrillation are provided within eight minutes of an episode, a person's chance of survival increases to 20%. Community Responders carry a life saving heart defribrillator and are trained to use both this and CPR.

The Fourth Link in the Chain of Survival - Early Advanced Care

The fourth link in the Chain of Survival is advanced care. Paramedics and other highly trained Emergency Ambulance Medical 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.

The trained Ambulance personnel monitor the patient closely on the way to the hospital, where more definitive diagnostic evaluation can occur.