The Importance of Good CPR

The heart is a pump. Its job is to draw blood from the circulation into its chambers, and then eject that blood back out. It doesn’t think or make decisions, just slows down or speeds up based on the instruction of the brain. It is an amazing piece of machinery that begins in the eighth week of life and never takes a break…..ever. But sometimes the pump fails. There are dozens of causes that lead to its failure, but the when the heart stops, so does the body, and no matter why it stops, if the pump doesn’t get re-started, life ends.

The heart receives its oxygen supply from the coronary arteries, the very first vessels that branch from the aorta as it leaves the left ventricle. The coronaries receive their blood during the diastolic, or relaxation, phase of a heartbeat, and the blood that courses through them is rich in oxygen. Other muscles in the body take a small percentage of the oxygen out of the blood as it passes through the capillaries, but the heart is greedy and takes nearly all of the oxygen out of the blood, so there isn’t much reserve. When the heart stops beating, the muscles don’t get that valuable oxygen, and they aren’t able to contract or do any work, so they can’t provide any new blood. The pump runs out of fuel.

Cardio-pulmonary resuscitation aims to fix the broken pump. By compressing the chest, the idea is to move blood around the body to make sure tissues get oxygen, which buys time until the heart can be restarted. Even more important, however, is CPR which moves un-oxygenated blood out of the coronary arteries and bring oxygenated blood back in to supply the hungry cardiac tissue. In effect, CPR primes the pump, giving it the valuable fuel that it needs to resume its tireless beating.

The earlier proper chest compressions are started, the sooner that oxygen-rich blood gets to the heart and other fragile tissues in the body. Keeping that blood circulating keeps the patient alive. It also moves the ACLS medications given to restart the heart from the veins to the heart tissue where it can actually do its job.

Great CPR saves lives, so let’s looks at how we can make good CPR great.