CPR: Mouth-to-Mouth Not Much Help

March 16, 2007 -- For adults who suddenly collapse, CPR is more effective if rescuers focus on chest compression over mouth-to-mouth ventilation.

CPR stands for cardiopulmonary resuscitation. It's used on people whose hearts suddenly stop beating. Using this emergency technique, you can keep a person alive until professional help arrives.

Currently, CPR includes two techniques. The first is mouth-to-mouth resuscitation, the so-called breath of life. The other is chest compression: pushing down hard on a victim's chest, more than once a second, pressing it down at least an inch and a half before releasing.

A major reason why bystanders don't give CPR to people who suddenly collapse is reluctance to put their mouths on the mouth of a stricken person. That reason no longer exists.

Now, for adults who suddenly collapse, there's powerful evidence that chest compression alone is far better than doing nothing. In fact, the new evidence suggests that by interrupting lifesaving chest compressions, mouth-to-mouth resuscitation may do more harm than good.

The striking evidence comes from Ken Nagao, MD, of Surugadai Nihon University Hospital in Tokyo, and colleagues. The researchers took a careful look at what happened to 4,068 adults who had an out-of-hospital cardiac arrest witnessed by bystanders.

More than 70% of the time, the bystanders did nothing when a person suddenly collapsed. Those victims were less likely to survive, and more likely to have brain damage if they did survive, than when bystanders tried to do something.

Bystanders bravely gave traditional CPR to 18% of victims. And those patients did much better than those who got no bystander aid.

But victims were 2.2 times less likely to suffer brain damage if they were among the 11% of patients who got chest compressions only -- without mouth-to-mouth resuscitation.

Death of Mouth-to-Mouth Resuscitation?

"This study just confirms what has pretty much become common knowledge," CPR researcher Alfred Hallstrom, PhD, of the University of Washington in Seattle, tells WebMD. "We did a randomized trial of compressions vs. CPR, and the results indicated that the compression-only technique was better. Subsequently, labs have done animal studies suggesting the same thing."

"This does not surprise me one bit," CPR researcher Joseph W. Heidenreich, MD, of Texas A&M Health Science Center, tells WebMD. "This is what all of us who have done CPR research have suspected for years. This is amazing data. Primarily, what people who suffer cardiac arrest need are chest compressions."

But not everyone is willing to give up on teaching people to give mouth-to-mouth resuscitation. One of them is Lance Becker, MD, director of the center for resuscitation science at the University of Pennsylvania and past chair of the basic life support subcommittee of the American Heart Association (AHA).

"The real message from this study is that doing something is better for saving people's lives than doing nothing," Becker tells WebMD. "Good compressions are associated with good things. It does not mean that ventilation is not an excellent thing as well."