CPR stands for cardiopulmonary resuscitation.
When a person’s heart stops, rescuers use CPR to manually pump blood through the body and make sure the brain and vital organs stay oxygenated. It’s a way to keep cardiac arrest victims alive in the precious minutes before rescuers arrive.
What is CPR and what does it do?
CPR is a combination of rescue breathing and compressions. When a rescuer breathes into a victim’s mouth, it fills their lungs with air—and delivers oxygen to their lungs. Then the chest compressions pump the blood through the body—as the heart would if it were working.
Without CPR, if oxygenated blood stops flowing to the brain and vital organs, the victim could die within minutes. And even if the heart is restarted, the brain could be permanently damaged if it’s been cut off from oxygen too long.
While imperfect, CPR keeps oxygenated blood flowing and buys time for the victim.
Types of CPR
There are a number of different types and techniques of CPR depending on the situation. These include:
Hands-only CPR. If you’re not a medical professional, this may be the type of CPR you learn.
Traditionally, CPR training for everyone included both rescue breaths and chest compressions. However, in 2008, the American Heart Association issued new guidelines that suggested lay rescuers skip the rescue breaths and provide chest compressions only.
There were several reasons for that. First, studies found that bystanders who were inexperienced with CPR wasted valuable time in trying to correctly deliver rescue breaths. Second, they found nervousness about the mouth-to-mouth contact required by rescue breathing stopped some people from providing CPR at all.
Hands-only CPR keeps things simple for lay rescuers—and increases the chances that a victim will get CPR if they suffer cardiac arrest outside of a hospital. It’s also more medically appropriate in some scenarios. All you do is push hard and fast in the center of the chest, at a rate of about 100-120 compressions per minute.
Traditional CPR. This is the type of CPR most of us would have learned before the new 2008 guidelines went into effect. It involves providing two rescue breaths for every 30 compressions. Again, the tempo should be about 100-120 compressions per minute, or about the beat of Stayin’ Alive by the Bee Gees.
The depth of compressions for an adult is about 5.5 centimeters, or two inches. Any deeper than that, and you may damage vital organs. If you go shallower, however, you may not be effectively pumping blood.
You won’t have a ruler when you deliver chest compressions—so this has to be estimated. However, it can take more strength than you’d think to push someone’s chest in two inches. Sometimes delivering effective CPR involves breaking a few ribs—but this is preferable to dying of cardiac arrest.
Child and infant CPR. Different guidelines apply when you’re providing CPR to a child or infant. What constitutes a “child” can vary; general guidelines apply to children up to the onset of puberty and those that weigh under 121 pounds. An infant is generally under 1 year of age.
There aren’t a lot of differences between performing CPR on an adult and on a child. With a child, rescuers should use either one or two hands, depending on the child’s size; and the depth of compressions is slightly shallower. As with adults, rescuers should provide 30 compressions to every 2 rescue breaths.
Infants also require a different protocol. Care must be taken because infants are so delicate. The baby’s head should only be tilted back slightly—just so the baby’s nose seems to be sniffing the air—for rescue breaths. And breathing should be done very gently; puff air into the baby’s mouth and nose with your cheeks, rather than using the entire strength of your lungs.
Compressions should be only about 1.5 inches deep, and done with two fingers at the center of the chest.
CPR for medical professionals. There are a number of different techniques for CPR performed by professional rescuers. Often, though not always, delivering CPR in a medical setting is a team effort.
For instance, a team of three people may perform Interposed Abdominal Compression (IAC) CPR, which involves alternating abdominal and conventional chest compressions to increase diastolic pressure in the aorta. This technique better stimulates blood flow to vital organs.
There’s even a method for providing CPR during open-chest surgery, where the surgeon compresses the heart directly using the thumb and fingers.
Vital CPR statistics
Approximately 475,000 people die in the US from cardiac arrest every year. That makes cardiac arrest more deadly than many kinds of cancer, as well as car accidents, gun violence, HIV, and house fires.
According to the American Heart Association, a large percentage of cardiac arrests occur outside of a hospital—where bystander CPR may be the difference between life and death for a victim. Most people don’t get bystander CPR, however; about 90% of those who experience cardiac arrest outside of a hospital die from it.
That’s a pretty grim statistic. But the AHA reports that according to data from 2014, about 45% of people who received bystander CPR during an out-of-hospital cardiac arrest survived. Receiving CPR immediately—even from someone who’s inexperienced in delivering lifesaving care—often makes the difference between life and death for cardiac arrest victims.
This highlights how important it is for everyone to learn CPR—even, and perhaps especially, if you don’t have a medical background. Many cardiac arrests occur outside of a hospital, where bystander CPR may be the only chance a victim has to survive while waiting for rescuers to arrive.