I guess I’m talking about defibrillation. Is it just the movies, or is it how defibrillation actually works in real life ?
I mean, you are trying to revive someone, trying to bring them back to life. What’s the worse thing that can happen ? Why do they start from low voltages and increase it slowly, and get more and more anxious and dramatic every time they say “Go up to 350” or whatever.
I mean, the person is already dead. What’s the risk ? Why do they act so hesitant ? What’s there to lose ?
In: Biology
Nah in real life we usually give the highest dose possible for defibrillation. Cardio version is a little different. But bringing somebody back we give the highest safest dose. We don’t want to futs around with shocking multiple times. Especially in obese patients where the current needs to travel further.
I feel it’s important to understand that defibrillation is trying to *stop* the heart from beating ineffectively (“fibrillation”). This allows the autonomous pace-maker trigger the heart to beat rhythmically.
I’m no expert but I suspect that increasing the voltage doesn’t really help this stopping in the most real-world cases.
At what point does it stop becoming a life-saving effort and become a barbeque?
The currents needed are miniscule in comparison to what we can actually muster
The general thought is that using the lowest level of energy to convert the heart from ventricular fibrillation, ventricular tachycardia or atrial fibrillation to a normal rhythm is best. The idea is that the greater the shock, the greater the risk of creating a parasympathetic nervous system discharge that can theoretically prevent the heart from restarting.
When portraying these types of situations, TV and movies often take liberties with medical accuracy in attempt to create tension or drama. Cardioversions for certain abnormal arrhythmias are very routine procedures that aren’t particularly dramatic. Cardiac arrests however can be quite dramatic, extremely emotional events when we are working hard to save someone’s life. Factor in things like a patient’s youth, an unexpected negative event, or an emotional connection you have with the patient or their family and the adrenaline gets pumping rapidly. So yeah- we will not hesitate to escalate the shock energy when indicated and tv doesn’t always show things the way they happen in real life.
I am not sure if they actually pump the voltage higher though from a laymans perspective it would make sense, that higher energy could help. But probably they will not start very low and also try to not defibrillate too often as the chance for it to work sinks rapidly if it doesn’t work on the first try.
People who are defibrillated are not dead though, they have ventricular fibrillation or other kinds of abnormal heart rhythms and the defibrillator can help to stop that. If somebody is dead or their heart just doesn’t do anything, defibrillation will not help.
In real life it is not recommended to shock a stopped heart. The shock is used in resuscitation to reset the heart rhythm.
Alternatively you can use frequent small shocks to recreate a rhythm via an external pacer but I don’t believe that’s what your referring to.
Tldr you don’t shock dead people.
That’s not how they work! You cannot jump-start a heart that has stopped beating. Defibs are used on hearts that are not beating properly. It shocks the heart to stop it temporarily, allowing it to reset and start beating in sync.
Hollywood is horrible for using accurate medical information. It’s all for show
Defibrillators aren’t used when your heart stops, so there is no reviving someone with one. The only thing that will start your heart pumping is someone slamming your chest (trying not to break your ribs) doing CPR. Nowadays they use automated external defibrillators (AEDs) that are used in conjunction with CPR and actually talk to let the rescuer know when to start, stop, and clear so that it can apply a jolt safely to get the victim’s heart beating regularly. The paddles being rubbed together and then placed on the patient while the doctor yells, “CLEAR!” is Hollywood theatrics.
Source: Entered cardiac arrest and revived 3 times in a short span of time in the ER.
Fun fact: The rhythm they teach someone doing CPR is “Stayin Alive” by the Bee Gees.
Increasing dose protocols are not generally used these days. Typically, every shock is delivered at maximum.
Historically, there have been some escalating protocols used, starting at for example 200 Joules, and if that doesn’t work, then switch to the maximum (typically 360 J) from then on. The idea being that, if it’s an easy defibrillation, you can save the skin burns, neurological problems, heart “stunning” and other side effects.
However, these days, defibrillators typically use lower energies with optimized shaped waveforms, which can have the same effectiveness as an old maximum energy shock with half the energy. These typically are set to maximum energy for every shock.
Heat and voltage go hand in hand. Applying a shock is destroying the heart.
The point of shocking is to STOP the heart. You know how people jolt up when they’re shocked in movies? That’s REAL. Your normal heart doesn’t do that.
Shocking the heart is just naturally violent. Less than 10% of people who are in cardiac arrest with a the shockable rhythm of ventricular fibrillation survive. Less and 2% with all the non shockable rhythms.
I’ve done CPR maybe 30 times, and personally shocked maybe 4 people. None have survived out of hospital. The way we treat cardiac arrest is very brutal and it’s the best we can do right now. Having the lowest voltage necessary to stop the heart will cause the least amount of damage. In theory.
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