How CPR Works


You're playing your usual weekend pick-up basketball game with friends. Without warning, one of your teammates suddenly crumples to the ground. You scream out his name, but there's no response. His face turns pale and bluish, and you can't see his chest rise and fall to breathe. You listen for a heartbeat, but you can't find a pulse at all. You quickly grab your cell phone and dial 911.

Every year, this type of scenario is played out more than 600 times a day in the United States alone. Without rapid medical intervention, the prognosis is grim. Sudden cardiopulmonary arrest is the leading cause of death for all adults, male or female.

Fortunately, modern medicine has come up with a number of tools to combat cardiopulmonary arrest. Many of these emergency procedures require medical training and/or complex equipment, but one, cardiopulmonary resuscitation (CPR), can be used in the field by lay people with only a little bit of training.

PLEASE NOTE: This article is not intended to be used as a method for teaching CPR. For proper CPR training, consult your local hospital or American Red Cross location for available classes.


Cardiopulmonary Arrest
Cardiopulmonary arrest simply means that your heart (cardio) and lungs (pulmonary) aren't working -- your heart isn't beating, and you aren't breathing. Many different things can lead to cardiopulmonary arrest, including:

A heart attack, for example, can damage the heart muscle and impede its ability to vigorously contract, resulting in cardiopulmonary arrest. You know that the heart is a muscle that expands and contracts under the electrical control of a special group of pacemaking cells. The pumping action of the heart pushes blood teeming with oxygen and other nutrients out to the rest of your body. If your heart isn't beating properly or at all, blood isn't supplied to your body, and oxygen and other vital nutrients don't get delivered to your tissues and organs (including your heart). With no energy to power your body, vital organs like your heart and lungs stop working, and you are in a state of cardiopulmonary arrest.

In a heart attack, something like a blood clot obstructs one of your coronary arteries and cuts off blood flow to your heart.

Cardiopulmonary arrest is an extremely dangerous situation. Within 4 to 6 minutes without oxygen, your brain cells begin to die off rapidly. With each additional minute, the damage builds up. Most people cannot survive long in such a state.


CPR Basics
Cardiopulmonary resuscitation (CPR) is a first-aid technique used to keep victims of cardiopulmonary arrest alive and to prevent brain damage while more advanced medical help is on the way. CPR has two goals:

While the modern emergency room has high-tech equipment and an arsenal of drugs to help treat victims of cardiopulmonary arrest, CPR is a simple technique that requires little or no equipment. What you do is pretty basic:

Here are the steps that make up CPR:

Photo courtesy of University of Washington

It sounds pretty simple, but as you can see above, CPR must be performed in a specific, timed sequence to accurately mimic your body's natural breathing pattern and the way your heart pumps. When someone collapses right in front of you, your first reaction is often sheer terror. But while you're panicked and unable to act, valuable minutes are slipping away. To counter this, many organizations such as the American Heart Association and the American Red Cross offer classes that train you in CPR and basic first aid and give you hands-on practice to hone your CPR skills. Then, if you are confronted with an emergency situation, you are prepared to jump into action.