I learned emergency cardiopulmonary resuscitation (CPR) in medical school more than forty years ago and it hasn’t changed much until now. It was always hard to do, but now it’s half as hard and not as unaesthetic, at least if the results of several studies are taken into account.
The problem was that you had to do two things simultaneously: maintain circulation by chest compression (usually pushing on the sternum) and aerate the mechanically circulated blood by artificial respiration (usually mouth to mouth resuscitation). This meant you stopped compression while inflating the lungs, then resumed it again. Recently the need for artificial respiration has been questioned and now two large scale studies, one in Sweden the other in Japan, have confirmed that compression alone is as good or better than the two together. These studies involved almost 15,000 witnessed cases of out-of-hopsital cardiac arrests and compared outcomes in the two scenarios (compression only and compression with mouth to mouth breathing assist):
“These independent findings confirm what our Resuscitation Research Group and others have found,” says Gordon A. Ewy, MD, director of The University of Arizona Sarver Heart Center, where Continuous-Chest-Compression CPR without mouth-to-mouth breathing was pioneered. “To rescue someone who suddenly collapses for no apparent reason, mouth-to-mouth breathing makes no sense.”
Shortly before the two latest observational studies were published, Dr. Ewy and his colleagues reported the results of a laboratory study suggesting that cardiac arrest patients face better odds of survival if they receive continuous chest compressions than if treated with standard CPR, in which chest compressions are interrupted by mouth-to-mouth breaths.
“Studies have shown over and over again that four out of five bystanders would not do CPR because of the mouth-to-mouth part,” says Dr. Ewy, who has commented on the two new studies in an invited editorial published in the same issue of Circulation. “If people don’t have to worry about the so-called rescue breathing, they are much more likely to actually do CPR on someone who needs it. This fact alone is the key to saving more lives. If someone calls the emergency medical services and does nothing, the individual has almost no chance of surviving.” (EurekAlert)
These are not the first studies to show this. Previously a paper in The Lancet also concluded you had a better chance of surviving a sudden cardiac arrest if chest only CPR was applied (Cardiopulmonary resuscitation by bystanders with chest compression only (SOS-KANTO): an observational study; Lancet 2007:369:920-926). The reasoning is that there is quite adequate oxygenation in the blood of some with a sudden arrest and that the urgent task is to keep the brain and heart perfused with it as quickly an continuously as possible. Even stopping for a fifteen or twenty seconds can make the difference.
I don’t know if this is correct or not (frankly it doesn’t sound that plausible to me) but I’m not going to argue with the results. For whatever reason, observations show that if I have a sudden cardiac arrest, you needn’t bother to breathe for me. Just keep the blood moving.