Optimal Conditions for Surviving CPR: Why Some Patient Outcomes are Better Than Others
There’s no question that CPR can save lives. But the survival rate is low; it’s estimated that only approximately 8-10% of people who undergo CPR survive, depending on a variety of factors.
However, despite the low survival rate, there are certain conditions under which CPR is more likely to be successful. Here are a few.
When the CPR is delivered immediately
Brain death happens fast in the case of cardiac arrest. Every minute counts, and your likelihood of surviving or avoiding incurring major brain damage goes down dramatically with every minute that passes, with brain death occurring within four to six minutes. That’s why patients who receive CPR immediately are more likely to live.
When the CPR is provided in a hospital
More than 380,000 people in the United States experience cardiac arrest each year, according to data from the American Health Association. One in five experience it outside of a hospital setting—at home, at work, or in a public place. In a hospital, you are more likely to get CPR from trained medical professionals immediately; and outside of the hospital, your chances of getting immediate help are lower, and ambulance response times can average about 12 minutes, depending on where in the United States you live. That’s an eternity for cardiac arrest victims.
When more than one bystander delivers CPR
If you experience cardiac arrest outside of a hospital setting, your chances of getting CPR from a trained medical professional go down significantly. However, if you do get CPR in a public place, your outcome is likely to be better if more than one bystander is involved. This is according to a Japanese study that was published in Resuscitation.
According to the data, 6% of victims survived with three or more rescuers present and 4% lived after receiving CPR from two individuals, while only 3% survived with one rescuer. Strangely enough, however, the benefit to having two or more rescuers isn’t present for patients who are given CPR at home; this may be because those who experience cardiac arrest in public places are generally healthier, having the ability to get out of the house.
When you suffer cardiac arrest in a wealthier neighborhood
According to a study by the Centers for Disease Control and Prevention, people in wealthy neighborhoods are more likely to provide CPR than those in poorer neighborhoods. The study looked at over 14,225 cases of cardiac arrest in 29 areas throughout the country. In higher-income neighborhoods, victims of cardiac arrest had a 55% chance of receiving CPR from a bystander. In poorer neighborhoods, the percentage went down to 35%.
The researchers performing the study suggested cost as a major reason for the reduced instances of bystander CPR; in poorer neighborhoods, people are much less likely to be able to afford classes.
When an emergency dispatcher directs the CPR
According to a study done in Japan and published in the Journal of the American Heart Association, those who experienced cardiac arrest outside of a hospital setting were more likely to live if their rescuer’s CPR attempt was directed by an emergency dispatcher. The study primarily looked at survival rates in children.
When you get rescue breaths in addition to chest compressions
The American Heart Association has recently promoted compression-only CPR full as the most appropriate for training most casual learners who are not healthcare professionals. This has been shown to improve the likelihood that a bystander will feel confident performing CPR—as the steps are easier—with little impact on survival rates.
However, the Japanese study cited above did find a difference in survival rates for children. According to this study, CPR with both breaths and chest compressions has better outcomes both for infants and children up to the age of puberty.
When you’re already fairly healthy. Many of the outcomes documented in the above studies are affected by how healthy the populations of people in the studies already are to begin with.
For example, the Japanese study that ran in Resuscitation showed that survival rates were noticeably better for people who received bystander CPR from two or more rescuers outside the home, but victims who received it from the same number of rescuers inside the home did not see a rise in survival rates. This may be due to the fact that those who experience CPR outside the home are probably more robust, being able to leave the house and walk around outside; some of the cardiac arrest victims who received it in the home may have already been suffering from severe health problems and could have been housebound.
In addition, while you are generally more likely to survive after receiving CPR in a hospital because of the likelihood you’ll receive it immediately from a trained healthcare professional, this is mitigated by the fact that people in hospitals tend not to be healthy to begin with. Even with the best care, those whose bodies are weakened by serious illness are less likely to survive, even with immediate and high-quality CPR.
Cardiac arrest can strike at any time—even in people who appear healthy. In general, you are more likely to survive a cardiac arrest if you don’t have any existing chronic conditions, congenital heart defects, or other health problems. Your body’s existing strength and endurance will make a big difference in whether or not you survive.
You can’t control all your risk factors for survival if you suffer from cardiac arrest. This is mainly a function of luck; you have to hope that you will receive CPR from a bystander or trained medical professional immediately, and that your health is already fairly good when you receive it. However, you can increase the potential of survival for others by undergoing CPR training yourself. It’s just possible that with your training, you could save a life.
American Heart Association: CPR Statistics
Centers for Disease Control and Prevention
American Heart Association: Circulation: Heart Disease and Stroke Statistics: 2010 Update