Adding mouth-to-mouth resuscitation to chest compression hurt, rather than helped, the survival of people who suffered cardiac arrest, a Japanese study found.
The study examined more than 4 000 adults who got emergency treatment from bystanders when they collapsed because their hearts stopped beating. The result: better neurological function in 10.1 percent of those who had only chest compression that started within four minutes of cardiac arrest, compared to 5.1 percent of those who also were given mouth-to-mouth resuscitation.
Similar benefits for chest compression alone were found for people who suffered abnormal heart rhythms and those with the breathing difficulty called apnoea.
No better with mouth-to-mouth
"However, there was no evidence of any benefit from the addition of mouth-to-mouth ventilation in any subgroup," the researchers reported.
The findings are published in the March 17 issue of the British journal The Lancet.
The report could lead to a further change in American Heart Association guidelines for cardiopulmonary resuscitation (CPR), said Dr Gordon Ewy, director of the University of Arizona Sarver Heart Centre, who has been proposing such a change for years. He wrote an editorial accompanying the journal report.
"Based on research conducted in our experimental resuscitation laboratory, we have been advocating chest compression alone for cardiac arrest," Ewy said. "We have done that because our surveys indicated that people are more likely to do bystander resuscitation if they have to do chest compression only, rather than having to do mouth-to-mouth resuscitation."
Resistance to mouth-to-mouth
Bystanders hesitate to do mouth-to-mouth resuscitation partly because they dislike the physical contact and potential risk of infectious disease, and partly because "it is a very complex psychomotor skill, and people are afraid that they might hurt the person," Ewy said.
As a result, he said, "three out of every four people who witness cardiac arrests won't do bystander CPR."
And when mouth-to-mouth ventilation is given, chest compression has to be stopped momentarily, Ewy said, adding, "You're only pressing on the chest for half the time."
The US heart association already appears to be leaning in that direction. It updated its CPR guidelines in November 2005, changing the ratio to 30 compressions for every two breaths, from the old ratio of two breaths for every 15 compressions.
"This article is extremely important, because it clearly shows what we've shown in our laboratory, that chest compression is better, and people are dramatically more likely to do that," Ewy said.
Whether the CPR guidelines are changed because of this study is almost beside the point, said Dr Lance Becker, director of the University of Pennsylvania Centre for Resuscitation Science and a past chairman of the American Heart Association's Basic Life Support Committee.
Anything will help
"The message of the study is that any CPR is better than no CPR, and that any attempt at resuscitation is better than doing nothing," Becker said. "The good news for people is that they can feel comfortable if they do anything. Anything they do is going to help somebody."
For bystanders who hesitate to help when they see someone collapse, because they are unsure about mouth-to-mouth resuscitation, Becker said: "If you're not sure you can do it very well, don't do it. But do chest compression. Whether the guidelines will change, I don't know, but the guidelines say if you feel uncomfortable with mouth-to-mouth resuscitation, then just do chest compression."