CPR is a lifesaving procedure that is performed when someone's breathing or heartbeat has stopped, as in cases of electric shock, drowning, or heart attack. CPR is a combination of:

• Rescue breathing, which provides oxygen to a person's lungs
• Chest compressions, which keep the person's blood circulating.

Permanent brain damage or death can occur within minutes if a person's blood flow stops. Therefore, you must continue these procedures until the person's heartbeat and breathing return, or trained medical help arrives.

CPR can be lifesaving, but it is best performed by those who have been trained in an accredited CPR course. The procedures described here are not a substitute for CPR training. (See www.americanheart.org for classes near you.)

Time is very important when dealing with an unconscious person who is not breathing. Permanent brain damage begins after only 4 minutes without oxygen, and death can occur in as little as 4 to 6 minutes later.

When a bystander -- whether friend, family, or stranger -- starts CPR before emergency support arrives, the chance of surviving is tripled! Nevertheless, when most emergency workers arrive at a cardiac arrest, they usually find no one giving CPR. This would be a good time to find a convenient CPR class and learn how to save lives.

Machines called automated external defibrillators or AEDs can be found in many public places, and are available for home use. These machines have pads or paddles to place on the chest during a life-threatening emergency. They use computers to automatically evaluate the heart rhythm and administer a sudden shock if, and only if, that shock is needed to get the heart back into the right rhythm. Most people in ventricular fibrillation cardiac arrest will survive if shocked within 3 minutes.

In adults, major reasons that heartbeat and breathing stop include heart disease, injuries and accidents, excessive bleeding, drug overdose, and sepsis (infection in the bloodstream).

• Unconsciousness
• No breathing
• No pulse

The following steps are based on instructions from the American Heart Association.

1. Check for responsiveness. Shake or tap the person gently. See if the person moves or makes a noise. Shout, "Are you OK?"
2. Call 911 if there is no response. Shout for help and send someone to call 911. If you are alone, call 911 even if you have to leave the person.
3. Carefully place the person on his or her back. If there is a chance the person has a spinal injury, two people are needed to move the person without twisting the head and neck.
4. Open the airway. Lift up the chin with 2 fingers. At the same time, push down on the forehead with the other hand.
5. Look, listen, and feel for breathing. Place your ear close to the person's mouth and nose. Watch for chest movement. Feel for breath on your cheek.
6. If the person is not breathing:
   • Cover the person's mouth tightly with your mouth
   • Pinch the nose closed
   • Keep the chin lifted and head tilted
   • Give 2 slow, full breaths
7. If the chest does NOT rise, try the chin lift-head tilt again, and give 2 more breaths. If the chest still doesn't rise, check to see if something is blocking the airway and try to remove it.
8. Look for signs of circulation -- normal breathing, coughing, or movement. If these signs are absent, begin chest compressions.
9. Perform chest compressions:
   • Place the heel of one hand on the breastbone -- right between the nipples.
   • Place the heel of your other hand on top of the first hand.
   • Position your body directly over your hands. Your shoulders should be in line with your hands. DO NOT lean back or forward. As you gaze down, you should be looking directly down on your hands.
   • Give 15 chest compressions. Each time, press down about 2 inches into the chest. These compressions should be FAST with no pausing. Count the 15 compressions quickly: "a, b, c, d, e, f, g, h, i, j, k, l, m, n, off."
10. Give the person 2 slow, full breaths. The chest should rise.
11. Continue cycles of 15 chest compressions followed by 2 slow, full breaths.
12. After about 1 minute (four cycles of 15 compressions and 2 breaths), re-check for signs of circulation.
13. Repeat steps 11 and 12 until the person recovers or help arrives.

If the person starts breathing again, place him or her in the recovery position. Periodically re-check for breathing and signs of circulation until help arrives.

• If a spinal injury is suspected, DO NOT tilt the head back when attempting to open the airway. Instead, place your fingers on the jaw on each side of the head. Lift the jaw forward. This keeps the head and neck from moving.
• If the person has signs of circulation -- normal breathing, coughing, or movement -- DO NOT begin chest compressions. Doing so may cause the heart to stop beating.
• Unless you are a health professional, DO NOT check for a pulse. Only a healthcare professional is properly trained to check for a pulse.

• If you have help, tell one person call 911 while another person begins CPR.
• If you are alone, as soon as you determine that the person is unresponsive, call 911 immediately. Then begin CPR.

• Eliminate or reduce risk factors that contribute to heart disease, such as cigarette smoking, high cholesterol, high blood pressure, obesity, and stress.
• Get plenty of exercise.
• See your doctor regularly.
• Always use seatbelts and drive safely.
• Avoid using illegal drugs.

Marx JA, Hockberger RS, Walls RM, eds. Rosen’s Emergency Medicine: Concepts and Clinical Practice. 5th Ed. St. Louis, MO: Mosby; 2002;64-82.

American Heart Association. Cardiopulmonary Resuscitation (CPR). Available at: http://www.americanheart.org/presenter.jhtml?identifier=4479.