The Early Show medical correspondent Dr. Emily Senay reports the most important first step for bystanders, if someone suddenly drops dead, is to call 911. Then, if the person isn't breathing or there's no pulse, CPR or cardiopulmonary resuscitation, should be given. CPR is the combination of mouth-to-mouth resuscitation and chest compressions that helps the brain continue to receive blood and oxygen while help is on the way.
The 911 dispatcher can help instruct a bystander over the phone how to give CPR, but that process can be time-consuming in a situation where every minute counts.
A growing number of experts are recommending dispatchers tell callers to perform chest compressions only and not to perform mouth-to-mouth resuscitation unless there's someone on the scene trained in CPR. In common situations where an untrained bystander is responding, mouth-to-mouth resuscitation can be sacrificed for the sake of performing the chest compressions quickly.
Demonstrating how to do CPR on a dummy, Dr. Senay explains chest compressions are the repeated pushing down on a victim's chest during cardiac arrest. It is an attempt to keep blood and oxygen flowing through the body, especially to the brain.
Mouth-to-mouth rescue breathing is also an effort to keep oxygen flowing to the brain. The American Heart Association still recommends bystanders be trained in the traditional combination of both chest compressions and mouth-to-mouth or rescue breathing, but they do support chest compressions in dispatcher-assisted situations where the simpler technique means a quicker response.
CPR with mouth-to-mouth has been standard practice for decades. It has been called into question recently by studies that suggest that more lives are saved by advising compressions alone and that people are more likely to give emergency resuscitation when they are advised to give only chest compressions.
There are cases where a bystander might be unwilling or unable to provide mouth-to-mouth rescue breathing. You should always use a protective mask if you do give mouth-to-mouth resuscitation to avoid transmitting disease. It is likely that a trained rescuer will increase the chances of survival by doing mouth-to-mouth breathing along with chest compressions. But chest compressions alone are significantly better than doing nothing.
It's estimated that an abnormal heart rhythm called ventricular fibrillation is the cause of most sudden cardiac deaths, so besides calling 911 and starting CPR, having one of the automated external defibrillators on hand to deliver a lifesaving shock may help in a lot of cases. It helps to know both how to do CPR and use an AED.