Bystander cardiac pulmonary resuscitation (CPR ) doubles the chance of survival from a cardiac arrest. The American Heart Association recently issued new guidelines on performing CPR.

Traditionally, those who provide CPR were instructed to give both chest compressions and breaths in a 15:2 ratio. The newer guidelines advise giving significantly more chest compressions relative to breaths (30:2). It turns out that the time spent interrupting compressions to give breaths may be better spent giving more compressions.

The new guidelines advise giving 30 compressions instead of 15 for every two breaths.

By giving more chest compressions, a grater amount blood flow is delivered to the heart muscle. If the heart should recover after a cardiac arrest the extra blood flow provides energy and allows for restoration of normal contraction. Conversely, if compressions are interrupted, the recovering heart may not be able to pump once restarted.

An article in Circulation recommends that bystanders who witness a person’s sudden collapse give compressions in the center of the chest after calling emergency medical services (EMS). The chest compressions should be hard and fast pushing motions without interruption. The article stresses that ventilation is still advisable if possible. However, chest compression alone is acceptable for those unable or unwilling to provide breathing assistance (ventilation).

It’s important to note that rescue breathing is especially critical in some cases. For example, if the cause of cardiac arrest is predominantly due to a breathing, or respiratory, problem such as drowning or choking. Additionally, the new guidelines do not apply to situations in which a person’s collapse is not witnessed and to children with cardiac arrest.

One goal of the new guidelines is to reassure bystanders, who may hesitate to provide mouth-to-mouth breathing to a stranger, that CPR alone is acceptable.