Cardio-Pulmonary Resuscitation (CPR)

The most life-threatening condition a first aider may be called to deal with is a casualty that is not breathing. You will need to confirm this by performing a primary survey. You need to ensure that the emergency services are called as soon as the absence of breathing has been established, as early help is vital to the survival of the casualty.

Without oxygen the brain cells will start to die within a few minutes, we can artificially breathe for and pump oxygen around the body by using a combination of chest compressions and rescue breaths, this is known as CPR.

Some circulation can be maintained by performing chest compressions. By pushing vertically down on the centre of the chest, you squeeze the heart between the chest and backbone; this forces the blood out of the heart and into the body tissues. When the pressure is released, the heart comes back to its normal shape and blood is sucked in, which is forced out by the next compression.

You breathe out enough oxygen to potentially keep the casualty alive until the emergency services arrive. This expired air can be forced into the casualty's lungs and air passages by performing rescue breaths.

In cases of sudden cardiac arrest the oxygen level in the blood will remain high for a few minutes so initially chest compressions will be more important than rescue breaths.