Defibrillation devices save lives using 1k times less electricity
phys.org
phys.org
Also, you should call the emergency number in your region and (at least in Australia) they'll transfer you to someone who can coach you through using the defib and performing CPR until professional help arrives.
Don't let that stop anyone from getting their CPR up to date though. The more experience you have the better equipped you'll be if you need to use it
> Placing [AED,] defibrillator pads on the chest and back, rather than the usual method of putting two on the chest, increases the odds of surviving an out-of-hospital cardiac arrest by more than two-and-a-half times, according to a new study.
"Initial Defibrillator Pad Position and Outcomes for Shockable Out-of-Hospital Cardiac Arrest" (2024) https://jamanetwork.com/journals/jamanetworkopen/fullarticle...
An emergency AED operator doesn't need to make that distinction (doesn't need to differentially diagnose a HA as a CA) , do they?
You just put the AED pads on the patient and push the button if they're having a heart attack.
But they do pump out a lot of juice. If you're touching the patient, it will HURT.
Potential Energy charge in a battery wants to return to the ground just the same.
There's no return circuit even with your feet in salt water if you touch only one post of a battery.
Connecting just 1.5V AA battery contacts with steel wool causes fire. But doesn't just connecting the positive terminal of a battery to the ground result in current, regardless of the negative terminal of the battery?
(FWIU that's basically why we're advised to wear a grounding strap when operating on electronics with or without discharged capacitors)
It will recognize ventricular fibrillation (the most common fatal arrhythmia). Technically, you don't shock pulsatile ventricular tachycardia, only pulseless. Not sure how AED's handle that, as I'm an anesthesiologist and would not use one at work - I'd read the rhythm myself and detect pulse either manually or with, say, a pulse oximeter. Never had cause to use an AED out in public.
Plain old CPR is what you do if they have pulseless electrical activity (the electrical system of the heart is working, but it's not pumping blood) or complete cessation of electrical activity (though it's probably not going to work in that case). We can use manual defibrillators as external pacemakers (much lower power output but still not going to be fun).
Should I assume that irrespective of this finding, pads should be placed where the AED indicates so that rhythm detection works correctly?
If you think of the traveling electrical power as a vector (pointing arrow), consider Anterior-Anterior vs Anterior-Posterior and draw a vector (arrow) between the pads. Which placement directs most of the power to the tissue of the heart? Anterior-Posterior does as the arrow goes directly through the ventricles, the area responsible for the VF/VT rhythm generation.
Once I learned how monitors, specifically Zoll, do rhythm analysis, and especially Zoll's Shock Conversion Estimator, I moved on and went back to school for engineering to help design products like these. It is all really cool stuff.
Not sure why the "us kids" comment. How come you aren't boasting about not wearing gloves and PPE? I've heard about "back in the day" how it was a badge of honor to be covered in someone else's blood. That shit ain't cool at all, but it does occasionally happen where blood does get on unprotected skin, it has happened to me.
Did we have to know as much as back in the 70s, 80s and 90s? No, not at all but that is advancement and not necessarily watering it down.
If I have an out-of-hospital emergency I definitely would want street medics and firefighter there for help. I am still shocked how often I've seen doctors and nurses loose their shit because they aren't use to having to think on their own or they don't have a team of 10 or 15 people there to back them up. I've seen it in firefighters and medics as well, just not as often. Most nurses aren't allowed intubate in a well lit hospital room, let alone lying on the asphalt of a highway or floor of someones home.
>Did we have to know as much as back in the 70s, 80s and 90s? No, not at all but that is advancement and not necessarily watering it down.
Sounds like you do understand the comment and agree with it, but still took offense.
We need to know much more now than ever before, as the number of treatments performed on scene has grown enormously. Not to mention survivability is orders of magnitude better.
I never met a LifePak 12 that did not flag every 12 lead it saw as an "Abnormal ECG".
The percentage of cardiac arrest survivors with positive outcomes 30 days after release depends on the type of cardiac arrest, and can range from 40% to 82%:
In-hospital cardiac arrest (IHCA) The 30-day survival rate for IHCA is around 25% in the United States and up to 35% in European countries. *In one study, the 30-day survival rate was 40%, with 34% of survivors having good neurological outcomes*.
Out-of-hospital cardiac arrest (OHCA) The probability of survival after OHCA can be increased by providing immediate cardiopulmonary resuscitation (CPR) and using an automated external defibrillator (AED). In one study, *10% of people who experienced OHCA survived with a favorable neurological outcome*.
They can save your life in a hospital, but just as easily kill you by mistake or side effect of whatever intervention they are doing. Also, walking (or being able to walk) is very important for longevity.
But the speed of the first response of the cardiac arrest is what matters. Since the brain is without oxygen. Assuming the person makes it to a hospital alive, they'll cool off the body to prevent brain damage. For every minute you survive, your odds get better.
If you don't know CPR, you might want to consider learning.
CPR has a much better success rate when something like an electric shock stops an otherwise-healthy person's heart.
The broken ribs were much more painful than the subsequent ICD implant. Although subsequently meeting the people who broke my ribs was actually a very happy and positive experience.
Please learn CPR if you can.
When I had an ICD implanted a few days later the surgical team stressed how massively lucky I'd been. They all stopped what they were doing and stared at me when the lead person read out my case history.
I don't think I had significant neurological issues as a result. Perhaps I should check my HN comment history to see if my rate of karma accrual changed around the date of the event.
Similar results have been observed in 2d simulations for more than 20 years, no one had managed to translate them to application.
One of the problems is, that 2 d and 3d reaction-diffusion systems are very different when it comes to so-called topological charge conservation. One can show that interactions of the applied electrical field can be described by its influence on the topological charges.
In 2d these topological charges are limited to points in 3d they form curves.
Points are limited to drifting and colliding, lines can twist, self collide, form rings and so on making translating 1d results to 3d quite difficult.
Yes. The paper says
>> In this study, a simple two-dimensional numerical model of atrial tissue containing anatomical heterogeneities – the essential ingredient responsible for the emergence of virtual electrodes – was used to explore ultra-low-energy defibrillation.
> no one had managed to translate them to application.
Yes. The paper itself has the following statements in its conclusion:
>> The approach considered here is impractical – it requires an accurate mathematical model of the tissue as well as complete knowledge of the state of the tissue at the initial time. Furthermore, computation of a defibrillating electrical field cannot be performed in real time.
My ICD is an Abbott Ellipse VR [0] and is 2 x 2.5 x 0.5 inches in size. It doesn't make too much of a bump under my skin. It was implanted in 2021 and I don't think was new then.
[0] https://www.cardiovascular.abbott/int/en/hcp/products/cardia...
> They’re already commercializing this.
Sorry to disappoint, and unfortunately, no. See other comments elsewhere. This study is based on a theoretical study of 2D simulated tissues. The original paper itself contains the disclaimer...
>> "The approach considered here is impractical – it requires an accurate mathematical model of the tissue as well as complete knowledge of the state of the tissue at the initial time. Furthermore, computation of a defibrillating electrical field cannot be performed in real time."
I thought this was about needing a smaller battery in defibrillators and was wondering if that is really a problem, but this makes more sense.
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Emoji Simulator: https://ncase.me/sim/?s=bz
Worth researching perhaps, lower power is much safer for a lot of other parts of the body, but is there reason to believe that this is correct? Are these models really that good?
As a matter of fact, as it is written right now, it makes little sense compared to the article's actual headline.