- something blocks the path for air to reach the lungs.
- some other gas takes the place of oxygen,
such as carbon monoxide.
- there is no air available to breathe in.
CardioPulmonary Resuscitation (CPR)
is a combination of simulating the breathing of the lungs and the pumping of the heart. You should know that CPR is effective less than 30% of the time. Does that mean it is futile? No way! The types of victims you will probably run into will most likely be on the high end of the probability scale. Recovery rates for people already in the hospital are about half that and less than 5% for elderly people with other medical problems. So, even though there's a good chance your efforts will fail, that person has a 0% chance if you do nothing. Let's talk about what CPR is and how it works.
CPR is made up of two parts: Rescue Breathing and Chest Compresssions
Rescue Breathing
You exhale air from your lungs into the victim's lungs so they can absorb oxygen. This assumes that there is adequate oxygen in your exhaled air. Air contains approximately 20% oxygen at sea level, 16% at 5000 feet elevation, and 13% at 10000 feet. When we breathe in air, our lungs absorb about 25% of whatever is available. So, at sea level, we exhale air with about 15% oxygen which is more than exists at 5000 feet and is adequate. When you breathe into a victim's mouth and have their nose closed, the air is forced into their lungs and you can see the chest rise. You have successfully gotten some amount of oxygen into the system.
Chest Compressions
You manually compress the heart by pressing down on the chest. When you let up on the chest, the heart expands. The hope is that by compressing and expanding the heart, the blood flows through it as designed. Unfortunately, you don't have an easy way to tell if blood is flowing. You can't feel for a pulse or see results. You just need to believe in your efforts.
CPR Effectiveness
When properly performed, CPR simulates from 20 to 40% of normal circulation. That is not enough to sustain life indefinitely, but will be sufficient to put off the start of cell death in the hope that revival tools arrive soon. You should not expect CPR to restart a heart and have the victim pop back to life like is shown on TV. Your job is to keep oxygenated blood flowing until life support services arrive. In communities with a thorough CPR training program and fast access to ACLS through an efficient Emergency Medical Services program, CPR can be effective up to half the time. Other places where CPR training is not promoted or where little ACLS support is available, the results are much less. Remember, your goal of administering CPR is to buy a little time for an emergency rescue team to arrive and revive.
So, what does CPR stand for? It stands for saving a life.