As important as CPR is in saving lives, it’s not always successful. In fact, many doctors report that they remember every patient who leaves their hospital or practice alive after receiving CPR—because the rates of success are so low.
It’s difficult to pinpoint the exact number of survivors, as most studies are broken up by specific types of victims. For example, in 2012 a study was done showing that only 2% of people who receive CPR from a bystander after collapsing in a public place make a full recovery. According to another from the University of Denver, approximately 18% of senior citizens who receive CPR treatment in the hospital are eventually discharged.
CPR plays the role of circulating blood and oxygen throughout the body until the victim can be given the specific lifesaving treatment they need. One reason for its low success rate is that CPR is often performed in extremely life-threatening situations—such as when a victim has had a cardiac arrest. The rates of survival for such occurrences are generally low to begin with.
It is never easy to predict the likelihood of survival for a patient who receives CPR. However, there are certain conditions and situations where a victim is more likely to make a recovery. These include:
When the person is generally in good health.
People in good physical health who need CPR—such as a healthy drowning victim who was pulled immediately from the water, a marathon runner who collapses on the track, or a physically vigorous person who experiences a mild heart attack—are more likely to make full recoveries after CPR.
Those who are less likely to recover are those victims who are already weakened—such as people with terminal or chronic illnesses. However, these people are more likely to need CPR to begin with.
When the person receives CPR immediately.
One of the reasons people who receive CPR do not survive is that they do not receive it soon enough. According to the American Heart Association, the chances of survival for a victim of cardiac arrest drop by 7 to 10 percent for every minute they do not receive CPR or defibrilliation. Brain death begins approximately four to six minutes after a cardiac arrest. For victims who do get CPR treatment immediately after suffering cardiac arrest, their chances of recovery are doubled.
The problem is that many people who experience cardiac arrest are not in a hospital, surrounded by doctors. They’re on the streets, in their homes and workplaces, and in other places where trained healthcare professionals may not be immediately available—and they may have to wait longer than they can afford to for an ambulance to arrive. This is why the American Heart Association advocates for more people to learn CPR, so that bystanders will be more qualified to step in and save lives—and it’s why we do, too.
When an AED is used.
An Automatic External Defibrillator, or AED, administers an electric shock to the heart that gets it going again in case of cardiac arrest. When it’s used in conjunction with CPR, it dramatically raises the victim’s chances of survival.
When hands-only CPR is used.
In the past, CPR was taught to include “rescue breaths”—where the rescuer breathes directly into the victim’s mouth. In 2008, however, the American Heart Association released new CPR guidelines that eliminated the requirement for rescue breaths.
In general, hands-only CPR is felt to work just as well, not necessarily better than, mouth-to-mouth CPR. But it may increase rates of survival because it’s easier to perform and eliminates the “gross” factor of having to put your mouth on a stranger’s. Because of these factors, it’s believed that hands-only CPR will increase the willingness of bystanders to give CPR treatment in the first place.
CPR is not always effective—but for many people who need it, it is necessary for survival. We may not be able to predict who is most likely to survive on an individual basis, but we can identify certain factors—the above among them—that increase a victim’s chance of survival. Hopefully, as our understanding of the technique improves and as more people learn CPR outside of the medical community, all victims’ chances of surviving with CPR will improve.