What is CPR?

Keeping the blood flow active – even partially – extends the opportunity for a successful resuscitation once trained medical staff arrive on site.

CPR is a critical step in the AHA’s Chain of Survival. The term Chain of Survival provides a useful metaphor for the elements of the ECC systems concept.

There are two commonly known versions of CPR:

1. For healthcare providers and those trained: conventional CPR using chest compressions and mouth-to-mouth breathing at a ratio of 30:2 compressions-to-breaths. In adult victims of cardiac arrest, it is reasonable for rescuers to perform chest compressions at a rate of 100 to 120/min and to a depth of at least 2 inches (5 cm) for an average adult, while avoiding excessive chest compression depths (greater than 2.4 inches [6 cm]).


2. For the general public or bystanders who witness an adult suddenly collapse: compression-only CPR, or Hands-Only CPR. Hands-Only CPR is CPR without mouth-to-mouth breaths. It is recommended for use by people who see a teen or adult suddenly collapse in an out-of-hospital setting (such as at home, at work, or in a park).

High-quality CPR should be performed by anyone - including bystanders. There are five critical components:

1. Minimize interruptions in chest compressions
2. Provide compressions of adequate rate and depth
3. Avoid leaning on the victim between compressions
4. Ensure proper hand placement
5. Avoid excessive ventilation

According to a study released by the Resuscitation Science Symposium, men are more likely to receive bystander CPR in public locations compared to women.

• Women and men receive similar CPR assistance within the home, but in public 45 percent of men received assistance compared to only 39 percent of women.
• Men were 1.23 times more likely to receive bystander CPR in public, and their chance of survival was 23 percent higher compared to women.

So why the discrepancy? It could come down to anatomy and a bystander being comfortable enough to perform CPR on a woman.

Many AHA lifesaving training courses are available online via ShopCPR. Courses that involve only cognitive learning can be completed entirely online. For courses that teach CPR, students must complete an in-person skills practice and testing session with an AHA Instructor after they complete the online portion. The Instructor will evaluate the student's skills and upon successful completion of both portions of the course, the student will receive a course completion card, valid for two years. See more information on blended learning and eLearning training.