How to measure high-quality CPR
Compression rate, depth and fraction are measures of high-quality CPR
Article updated February 8, 2018
The American Heart Association guidelines released in 2010 (and in subsequent releases) focus heavily on prioritizing high-quality chest compressions, but what does that actually mean?
There are several measurements of CPR quality that all medical providers should be aware of.
Compression rate is the measurement of how fast CPR is being performed. The idea used to be that faster was better.
Now, however, it is becoming clear that a rate of 100-120 compressions per minute is ideal. If compressions are too slow, blood is not being circulated effectively around the body. If compressions are too fast, the heart does not have enough time to adequately fill so cardiac output drops off.
Compression depth is the measurement of how deep the sternum is pushed down during CPR. The preferred compression depth is two inches for most adults.
It is equally important to allow the chest to fully recoil following each compression. By allowing full recoil, rescuers allow the heart to fill with blood completely which improves cardiac output.
Caregivers should never rest their weight on the patient’s chest during CPR.
Compression fraction is the percent of time during the cardiac arrest that CPR is actually being performed. Each time CPR is stopped the output of the heart falls off dramatically. After CPR is restarted, it takes time to build up cardiac output again.
Minimizing interruptions during CPR is one of the most important ways to ensure high quality resuscitation. This finding has led some EMS systems to avoid the use of advanced airways with a preference placed on an OPA or NPA if the providers can maintain a patent airway.
Continue compressions as another rescuer places an AED or obtains IV or IO access.
Ventilatory rate is the rate at which rescuers are delivering ventilations often via a bag-valve mask. While patients need ventilation, over-ventilating or hyperventilating the patient can be detrimental to their outcome; too much ventilation can increase pressure in the chest cavity and may reduce the output of the heart.