August 2, 2010

CPR without mouth-to-mouth may be better for cardiac victims

A leading expert in cardiopulmonary resuscitation says that two new studies from U.S. and European researchers support the case for dropping mouth-to-mouth, or rescue, breathing by bystanders and using “hands-only” chest compressions during the life-saving practice better known as CPR.

The findings, the expert says, concur with the latest science advisory statement from the American Heart Association, published in 2008, recommending hands-only (or compression-only) CPR by bystanders who are not adequately trained, or who feel uncomfortable with performing rescue breathing on other adults who collapse from sudden cardiac arrest.

In an editorial accompanying the studies, published in the New England Journal of Medicine online July 29, cardiologist Myron “Mike” Weisfeldt, physician in chief at The Johns Hopkins Hospital and director of the Department of Medicine at Johns Hopkins University’s School of Medicine, says that “less may be better” in CPR, calling the findings straightforward, practical and potentially life-saving.

The two studies were conducted between 2004 and 2009 on more than 3,000 men and women who needed CPR. Among the key findings are that survival rates were similar for adults who received their CPR from bystanders randomly assigned to provide only chest compressions and those who were instructed to do standard CPR with rescue breathing. All bystanders involved in the studies were instructed by 911 telephone dispatchers on which CPR method to use. One study showed survival rates after one month of 8.7 percent and 7 percent, respectively, while the other showed survival rates at time of hospital discharge of 12.5 percent and 11 percent. The researchers say that the numbers were statistically the same.

“It is very important to understand that the patients in this study were adults and that for most children who suffer cardiac arrest, such as drowning victims, we must do rescue breathing,” said Weisfeldt, a past president of the American Heart Association.

He also noted that there are adults with breathing-related causes of sudden death where rescue breathing should be performed, including patients with sudden, acute heart failure; severe chronic lung disease, or acute asthma; and cardiac arrest.

However, Weisfeldt said, “for people who are not well-trained or who are looking for a simple way to help save a life, chest compressions only, at least until the emergency care unit arrives, can be life-saving, even without rescue breathing.”

Weisfeldt says that the studies’ results could lead to stronger national guidelines on how bystanders should perform CPR. An update is expected to be announced at an AHA annual meeting in November. Guidelines, he says, will likely recommend a steady 100 chest compressions per minute with less emphasis on rescue breathing.

Weisfeldt points out that both recent studies, and previous animal studies, have shown that hands-only CPR worked best for certain types of cardiac arrest, mostly instances resulting from an abnormal heart rhythm (and requiring defibrillation).

CPR has been in practice in the United States since 1960, when Johns Hopkins researchers William Kouwenhoven, Guy Knickerbocker and James Jude published the first data on the benefits of what was then called “cardiac massage.”

Weisfeldt says that further research is needed to see if a combination of CPR and rescue breathing is better at saving lives in certain kinds of cardiac arrest, and to see how and if the public can be trained to recognize and distinguish between types of heart attack.

A third of the estimated 300,000 Americans each year whose hearts suddenly stop beating outside of a hospital receive CPR to keep blood and oxygen flowing to the body’s vital organs in the torso until emergency services personnel arrive. CPR performed by good Samaritans is known to nearly double the survival chances of people who suffer sudden cardiac arrest.

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