My regular readers are a sharp bunch, so you probably already know that cardiac arrest – the cessation of a pulse and of blood circulation – is very very bad for you. Most doctors don’t recommend it. Nevertheless, hundreds of thousands in the U.S. every year suffer cardiac arrest outside of a hospital, frequently due to a heart attack. Cardiopulmonary resuscitation (CPR) was developed 50 years ago for just such situations. Decades of data strongly support that the following two factors are key in determining survival after out-of-hospital cardiac arrest.
- the time from collapse to defibrillation (the use of electricity to shock the heart into a stable rhythm)
- the performance of CPR by bystanders until emergency medical personnel arrive
Despite this information, only a third of cardiac arrest patients receive CPR from bystanders.
Two years ago the American Heart Association revised their recommendations for CPR done by bystanders. (I wrote about it back then. See the link below.) The new recommendations removed mouth-to-mouth rescue breathing and focused on chest compressions. The recommendations have only two steps.
If you see someone collapse:
- Call 911
- Push hard and fast in the center of the chest
These recommendations received substantial support from two studies in this week’s New England Journal of Medicine. The studies, one Swedish and one American, involved emergency dispatchers who were called regarding a witnessed cardiac arrest. The dispatchers instructed the callers on how to perform CPR. The calls were randomized so that half of the bystanders were instructed to perform traditional CPR with 15 chest compressions alternating with two rescue breaths. The other half of the callers were instructed to do chest compressions only, without rescue breaths.
Both studies showed equal survival rates between the two groups, suggesting that rescue breaths are not helpful. The previous emphasis on rescue breathing may also have discouraged bystanders from doing anything at all, as many people find mouth-to-mouth resuscitation objectionable because of infection risks or general ickiness.
The major exception to these guidelines is cases in which the patient collapsed because of a breathing problem, such as choking or drowning. In these cases rescue breathing should be done with chest compressions. Since kids don’t have heart attacks, a collapsed child should be assumed to have had a breathing problem.
The bottom line is that if you see someone collapse, get help, and do something. You can’t make the situation worse, and prompt chest compression can make things much better.
Wall Street Journal article: In Many CPRs, Skip the Mouth-to-Mouth
Los Angeles Times article: Compression CPR Found Effective
My post in 2008: American Heart Association Recommends Hands-Only CPR
New England Journal of Medicine article: CPR with Chest Compression Alone or with Rescue Breathing
New England Journal of Medicine article: Compression-Only CPR or Standard CPR in Out-of-Hospital Cardiac Arrest
New England Journal of Medicine editorial: In CPR, Less May Be Better