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 you’re doing chest compressions to save someone who has stopped breathing there roughly a 10% chance they will survive but a 0% chance if you don’t So it’s often worth it anyway.
However it does keep the blood flowing and can prevent brain damage until a defibrillator is available which has a much higher chance of saving someone who has stopped breathing.
The heart is also protected by the lungs and breast plate.
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. 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).
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.
While we’re on the topic of CPR, I want to address the myth that CPR “almost never works”. It’s great at what it does, which is pumping blood through the body enough to keep vital organs supplied with a bare minimum of oxygen so they can survive.
However, there’s usually a reason why the heart has stopped beating and in most cases, CPR can’t reverse that reason. If the patient is in a car crash and has completely bled out, CPR won’t get any blood back into their system. Or if they’re at the end stage of a terminal disease, CPR can’t magically cure the disease.
But in cases where the cause for the cardiac arrest is simple and easily reversed, chances of survival are much higher. For example, if someone is drowning and you get them out of the water within a few minutes of cardiac arrest, CPR is very effective, with the majority of patients surviving. Here’s a study with 113 patients who were resuscitated after drowning and only 8 were confirmed dead. For 20 patients, the outcome was unknown, but even if they all died as well, that’s still a 75% survival rate.
It’s not that CPR doesn’t work, it’s that outcomes after resuscitation usually aren’t great. The study doesn’t disclose ages or neurological outcomes post-rescuscitation so that limits my interpretation but quick rescue and quick CPR is key in those acute, single reason emergencies. That isn’t to say in an emergency situation you shouldn’t try especially since you don’t know that person’s wishes. There are good outcomes but usually for underlying healthy people who had one thing go wrong. Think the athlete who’s heart stops on the field for some reason.
I’ve admitted at least a thousand people into a hospital through the ER and I tell everyone that it’s not like on TV. If you’re older, sick, multiple chronic diseases, don’t take care of yourself, etc. the chances of any kind of quality of life after CPR is limited. Death is terrifying and I understand them wanting to try but it’s just not realistic a lot of the time. We need better deaths in the US and more in-depth end-of-life conversations with our patients. That should be starting in the PCP’s office. Trying to discuss that with a patient in the ER who’s already scared isn’t ideal. I’ve seen patients with do not resuscitate/do not intubate orders on file change their mind when they’re suffocating and panicking then once they’re more stable immediately change their mind back.
I’ve never heard of a punctured heart personally, but I do think it’s possible. A punctured lung is much more common. But both conditions are usually treatable if the patient survives.
CPR does carry some risks, but not doing CPR is guaranteed to be lethal. So any risk (to the patient) is worth taking at that point.
