Eli5: when giving CPR, wouldn’t the lungs be compressed and released, creating a vacuum and providing some oxygen? If so, how does brain hypoxia still occur?
In: 3
The expansion and contracting of your lungs is controlled by the diaphragm, a muscle that sits at the bottom of the ribcage; well below the area compressed by CPR thrusts. Without the movement of that muscle, we don’t get full breaths.The fact is, humans actually aren’t all that efficient with oxygen. We breathe out about 75% of the oxygen that we breathe in. So a single breath can provide enough oxygen to supply the heart and brain for a few minutes.
That time can be extended with CPR forcing the blood around to keep the brain well oxygenated. The thrusts are so important that often times it is better to do continual compressions without any rescue breaths. Many defibrillator units echo this by not instructing the user to give rescue breaths. Rather it goes through cycles to check for a rhythm, then asks the user to continue compressions if no rhythm or no shockable rhythm is found.
Latest Answers