What is cardiopulmonary resuscitation (CPR)?

Indications and Procedures

Cardiopulmonary resuscitation (CPR) is generally performed on a person who is in cardiac arrest. In the United States, someone dies from sudden cardiac arrest (SCA) every two minutes. Cardiac arrest occurs when a person has no heartbeats or insufficient heartbeats to pump blood to the brain and other vital organs. Without sufficient blood flow, these organs do not receive enough oxygen to function normally; after about four minutes, they begin to die. This life-threatening situation requires immediate attention to keep the person alive. If medical personnel are not immediately available, then emergency medical services (EMS) should be called and CPR should be initiated.

Cardiac arrest can have many causes. The most common is a severe heart attack. Many heart attacks do not require CPR, but if a person is unconscious with no pulse, then CPR should begin as soon as possible. Other causes of cardiac arrest that may require CPR are drowning, suffocation, drug overdose, electrocution, stroke, and other types of brain damage. In each of these situations, the heart is not contracting and pumping blood.

CPR includes two distinct operations, breathing air into the person’s lungs and compressing the chest. In mouth-to-mouth breathing, sometimes called artificial respiration,
the rescuer breathes air into the person’s lungs, causing the chest to rise and fall with each breath. The rescuer’s expired air is 16 percent oxygen, as compared with 21 percent oxygen in room air. This expired air has enough oxygen to maintain life. It is recommended that an individual providing mouth-to-mouth breathing use a protective device, such as a CPR mask or shield, to avoid transmission of potentially infectious body fluids. The mask or shield devices can be purchased for a small cost online or from uniform stores or university medical bookstores.

Chest compressions involve the application of pressure to the lower half of the breastbone. The external pressure increases the pressure in the chest, pushing blood to the brain and the rest of the body. Although this procedure circulates only 25 to 33 percent of normal blood flow, it is sufficient to keep the person alive when used in conjunction with mouth-to-mouth breathing.

In an emergency situation, CPR can be administered by one or two people. One person can alternate mouth-to-mouth breathing and chest compressions. Performing CPR for several minutes, however, can be exhausting. If two certified rescuers are present, one can do the mouth-to-mouth breathing while the other performs chest compressions. Two people can do the procedure more efficiently and for longer periods of time.

Uses and Complications

Cardiopulmonary resuscitation should be used only if a person is suffering from cardiac arrest. There are no other applications. Even when CPR is correctly performed by experienced, certified medical personnel, injury can occur to the individual receiving CPR. These injuries may include broken ribs, bruising of the heart, and tearing of the liver and/or the spleen. However, these injuries should not deter an individual from performing CPR. Cardiopulmonary resuscitation is only performed when a person is clinically dead, without a pulse or respiration. Individuals should take a course and become certified to learn the most effective and safest techniques.

Effective CPR sends oxygen to the vital organs to prevent permanent tissue death, but it cannot alter abnormal electrical energy that may be occurring in the heart muscle. This abnormal electrical energy does not allow the heart to pump blood adequately throughout the body. Medical attention is generally needed to restart the heart contractions, and CPR must be continued until EMS personnel arrive. Emergency medical personnel will defibrillate the heart by sending an electric shock through the chest in an attempt to correct the abnormal electrical energy in the heart so that it can resume normal contractions.

Almost anyone can become certified in CPR. The American Heart Association and the American Red Cross offer classes with certification. These organizations are also involved in campaigns to have as many people certified as possible because CPR doubles a victim’s chances of sudden cardiac arrest survival. Therefore, the more people that are certified, the more likely it is that someone can perform CPR in an emergency and the more likely it is the victim will survive.

Another program to reduce deaths from sudden cardiac arrest includes the use of automated external defibrillators (AEDs). These units are computerized and allow a person with minimal training to defibrillate a heart. An AED unit has simple steps to follow with voice and print instructions. The machine has built-in safety features to prevent a person from receiving defibrillation that is not needed. AED units have been placed in work sites, stadiums, airports, and other places where large numbers of people are found. Designated people in these areas are trained to use the AEDs. If the first defibrillation shock is administered within six minutes, then the victim has an approximately 45 percent chance of survival.

Perspective and Prospects

Mouth-to-mouth breathing dates to biblical times, when it was used by midwives to resuscitate newborns. However, it fell out of practice until the 1950s, when it was rediscovered by James Elam and Peter Safer. In 1960, other physicians found that chest compressions could attain sufficient circulation, and these compressions were combined with mouth-to-mouth breathing to create a CPR procedure similar to what is used today.

Bibliography

American Academy of Orthopaedic Surgeons and Alton L. Thygerson. First Aid, CPR, and AED. 6th ed. Sudbury, Mass.: Jones and Bartlett, 2011.

American Heart Association. “2005 AHA Guidelines for CPR and ECC.” http://www.americanheart.org, 2013.

American Red Cross.American Red Cross First Aid: Responding to Emergencies. 4th rev. ed. Yardley, Pa.: StayWell, 2007.

Bergeron, David J., et al. First Responder. 8th ed. Upper Saddle River, N.J.: Pearson/Prentice Hall, 2009.

“CPR: Are We Doing It Wrong?” Harvard Health Letter 30, no. 7 (May, 2005): 1–3.

Finucane, Brendan T., and Albert H. Santora. Principles of Airway Management. 4th ed. New York: Springer, 2011.

Kohnle, Diana. "Cardiopulmonary Resuscitation for Children Age 1 to Early Teens." Health Library, March 15, 2013.

Kohnle, Diana. "Cardiopulmonary Resuscitation for Infants." Health Library, March 15, 2013.

Kohnle, Diana. "Cardiopulmonary Resuscitation for Teens and Adults." Health Library, March 15, 2013.

MedlinePlus. "CPR." MedlinePlus, May 22, 2013.