When a person collapses from cardiac arrest, performing C-P-R greatly improves the chances for survival. But a new study found chest compressions… not mouth-to-mouth resuscitation… is the key to helping someone recover.

The Japanese study, published in the journal The Lancet, found more people are likely to pull through without brain damage if the rescuer focuses on chest compressions instead of rescue breathing. Some experts recommend dropping the mouth-to-mouth part of C-P-R altogether.

The results confirm what some American medical experts already believe. The American Heart Association revised its C-P-R guidelines more than a year ago to emphasize compressions. The new recommendations call for thirty compressions for every two breaths instead of fifteen. Stopping the compressions to blow air into a person’s lungs detracts from the more important task of keeping blood flowing to the brain and heart.

In the Japanese study, researchers analyzed more than four-thousand adults who went into cardiac arrest in the presence of bystanders. Twenty-two percent of those who received only the compressions survived with good neurological function. In comparison, only ten percent had a good result with conventional C-P-R.

However, researchers only studied the effects of the fifteen compressions to two breaths; not the newly recommended ratio of thirty to two.

Eliminating rescue breathing may have an added benefit. Bystanders who are squeamish or confused by the correct number of chest compressions to breaths may be more willing to perform C-P-R if they don’t have to perform mouth-to-mouth.