If proper CPR involves compressing the chest so much such that the ribcage might break - doesnt that breakage risks a bone puncturing the heart?
If proper CPR involves compressing the chest so much such that the ribcage might break - doesnt that breakage risks a bone puncturing the heart?
Doesn’t the defib stabilise the heartbeat rather than getting it going again?
Yes, a heart that has completely stopped beating cannot be restarted by defibrillation. It only works in a condition called ventricular fibrillation, when the muscle fibers of the heart are still contracting, but are no longer “in sync”. This causes the heart to twitch chaotically, which is not an effective way to pump blood. And without blood pumping, the heart itself does not receive any oxygen as well, so it will eventually go into a complete flatline after a few minutes of untreated ventricular fibrillation.
The electric shock helps the fibers resynchronize. If you want to see the effect directly, here’s a video:
https://www.youtube.com/watch?v=HCbawp9ZSnY
Be warned, it shows an open chest and an exposed heart, most likely during heart surgery. They are using spoon-shaped internal defibrillation paddles. In the beginning, you can see the heart in ventricular fibrillation. It’s twitching chaotically and not pumping any blood. After defibrillation, it starts contracting rhythmically again.
Yes if the heart has flatlined completely then it won’t be started again by AED. But if they are in cardiac arrest then the heart rate is erratic and doesn’t function normally but can be returned to normal with a defibrillator.
Someone can be in cardiac arrest and have an asystoly or PEA. In fact, whenever someone has an asystoly or PEA they are in cardiac arrest.
Yes. Defibrillator is useless if your heart has stopped.
That’s incorrect.
Someone might be not breathing for a number of reasons. Most likely however, when you find them unconscious & not breathing on the street it’s for cardiac reasons. And then a defibrillator is the one best treatment for that (if the heart has a shockable rhythm that is).