All rescuers should perform chest compressions for all persons who are unresponsive and not breathing normally.
All rescuers, including health care professionals, should use unresponsiveness and absence of normal breathing to identify the need for resuscitation. Palpation of a pulse is unreliable and should not be performed to confirm the need for resuscitation.
Immediately upon recognising that the casualty is unconscious and not breathing, compressions must be commenced.
Locating the site for Chest Compressions
Place the heel of the hand in the centre of the chest or on the lower half of the sternum, with the other hand on top. Avoid compression beyond the lower limit of the sternum. Compression applied too high is ineffective and if applied too low can cause regurgitation and/or damage to the internal organs.
Method of Compression
In infants, the two-finger technique should be used by lay rescuers to minimise transfer time from compression to ventilation. Having obtained the compression point, the rescuer places two fingers on this point and compresses the chest.
Children and Adults
Either a one or two hand technique can be used for performing chest compressions in children.
Interruptions to chest compressions must be minimised. A person requiring chest compressions should be placed on their back on a firm surface before commencing chest compressions to optimise the effectiveness of compressions.
Compressions should be rhythmic with equal time for compression and relaxation. The rescuer must avoid either rocking backwards and forwards or using thumps or quick jabs. Rescuers should allow complete recoil of the chest after each compression.
WITHIN 3-4 MINUTES OF NOT BREATHING A CASUALTY WILL START TO SUFFER IRREVERSIBLE BRAIN DAMAGE.
The lower half of the sternum should be depressed approximately one third of the depth of the chest with each compression. This equates to more than 5cm in adults, approximately 5cm in children and 4 cm in infants.
Rescuers should perform chest compressions for all ages at a rate of 100 to 120 compressions per minute (almost 2 compressions/second). This does not imply that 100-120 compressions will be delivered each minute since the number will be reduced by interruptions for breaths given by rescue breathing.
When performing compressions, if feasible, change rescuers at least every two minutes to prevent rescuer fatigue and deterioration in chest compression quality, particularly depth.
Changing rescuers performing chest compressions should be done with a minimum of interruptions to compressions