BLS CPR Algorithm
If you are alone and attempting to perform CPR, make sure the victim is face up, on a hard, flat surface. Kneel down at the victim’s side, with your knees at the level of the patient’s chest. Put the heel of your palm on the lower half of the patient’s breastbone. Cover that hand with your other hand and lock your arms in a straight position. Each chest compression should be delivered forcefully and quickly.
The chest should depress 2 to 2.4 inches in adult and adolescent patients and at least one third of the chest diameter in younger victims. Likewise, the chest should fully recoil in between compressions.
You will need to provide 100 to 120 chest compressions per minute and chest compressions should continue until an AED is attached, powered up, and ready to go or EMS arrives and takes over in the resuscitation. The AED can be used as soon as it is ready to read a rhythm.
For adult victims, it is not necessary to provide mouth-to-mouth during CPR. If you are comfortable providing mouth-to-mouth and are confident that you can do so successfully, deliver two breaths after every 30 compressions. In children and infants, the ratio is the same two breaths for every 30 chest compressions. Rescue breathing and mouth-to-mouth are important in children and infants because most cases of arrest primarily involve the pulmonary system.
If you can call for help and there is an AED close by, you may leave the patient briefly to get help. When possible, calling EMS with your cell phone is preferable to leaving the patient.
In all adults and adolescents or in a witnessed collapse of a child or infant, you can leave the patient to get help before starting CPR if necessary.
In an unwitnessed arrest of a child or infant, perform CPR for 2 minutes before leaving the patient to get an AED or to call emergency medical services.