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> If it can't detect a treatable condition it doesn't just blat you with electricity for the sake of it

I was taught how to use one on a course where the instructor said he used to enjoy teaching students this fact by allowing them to take turns attempting to use a live defibrillator on him.

He got away with it for many years until his boss found out and put a stop to it because the company insurance wouldn't cover the company (despite clear witnessed consent being given by the instructor).

On the plus side, the company didn't ban his teaching method of NPA (Nasopharyngeal Airway) insertion. ;-)

> manual CPR which had kept my brain supplied with oxygen

Manual CPR done correctly is critical, and yes if done correctly you WILL end up with broken ribs. Mouth-to-mouth is not deemed particularly necessary these days (since the act of correct CPR will draw oxygen in anyway), better to focus on proper CPR and wait for the ambulance to turn up with high-flow oxygen from a tank.

> If I had been a 20 minute walk away, I would be dead (or brain damaged)

Yes. The most effective time for defib use is in the first 5 minutes. That's not to say you should not have a go after that time, but its effectiveness does drop away quite quickly.

> Yes. The most effective time for defib use is in the first 5 minutes. That's not to say you should not have a go after that time

Totally! After my experience I booked myself on a defibrillator training course, and looking back now, the main thing I remember from the course was the instructor's key learning point that you should get the defib out as soon as you can and let it take over. It pretty much can't make things worse than doing nothing.

[Edit - that and CPR, it goes without saying]

Exactly. Hollywood always gets it wrong--shocking a non-beating heart does nothing (in fact, the whole purpose of the machine is to *stop* the heart!). The machines look for improper, useless beating and will not fire unless they see it. It's still possible to get the pads sufficiently wrong that the shock is wasted, but there's no way to shock someone who doesn't need it.

For a non-beating heart the only treatment is CPR until the docs can deal with whatever caused it not to beat in the first place.

When I was 3 years old my older brother tried to kill me and very nearly succeeded. As best anyone can recon, I was no breath no pulse for about 10 minutes. My life was saved by an EMT doing CPR. These people are incredible, and deserve every bit of praise and validation we can give them.

> Mouth-to-mouth is not deemed particularly necessary these days (since the act of correct CPR will draw oxygen in anyway), better to focus on proper CPR and wait for the ambulance to turn up with high-flow oxygen from a tank.

Mouth-to-mouth isn't critical, but clearing the airway is. I remember one story from a first-aid refresher a few year, the guy doing it said he arrived at a car crash (doing a stint on an ambulance). A girl had been hit and was lying on the floor. Nobody had touched her in case they broke her neck or something.

She wasn't breathing. The ambulance had arrived within about 5 minutes, which was too late. Tilting her head back would likely have saved her life.

> Mouth-to-mouth isn't critical, but clearing the airway is.

Sure, but that goes without saying. Anybody who's been taught DRSABCD should know that.

Its also the reason why the FIRST thing you do when someone is choking is call for an ambulance (ideally on loudspeaker so you can get on with it at the same time, or, preferably get someone else to, if available). Even if you are successful in dislodging the item, they will still need a once-over by a trained medic because if you did it by the book it comes with side-risks.... so whichever way you won't be wasting the ambulance's time.

If you start trying things on choking and find you're not getting very far and then call an ambulance .... it'll probably be too late.

(Goes without saying that for heart issues, ambulance is also a high priority, but choking is far more time critical in the grand scheme of things).

> Sure, but that goes without saying

Clearly not for the average person at that accident scene where the girl died, and indeed I believe that for most people - especially in a crowd - the first and last action is "shock". Maybe someone will phone for help.

My first aid training comes from hostile environments, where catastrophic bleeding fits in before airway. Unlikely to find someone with a missing limb down the high street, but there's not much point in CPR if the blood you pump is gushing out of the femoral artery.

I remember reading of one--kid ran behind the car that was backing out. *Minor* injuries, but fatal because the people were afraid to mess with a head wound. The kid was knocked unconscious and had a nosebleed--he drowned on the sidewalk.

> Mouth-to-mouth is not deemed particularly necessary these days (since the act of correct CPR will draw oxygen in anyway), better to focus on proper CPR and wait for the ambulance to turn up with high-flow oxygen from a tank.

Not exactly. More precisely, for the “average” out of hospital cardiac arrest in an adult, chest compressions are more important than expired air resuscitation (mouth to mouth). The guidance to the public was watered down because there was recognition that members of the public were not enthusiastic about starting mouth to mouth resuscitation with a stranger. Mouth to mouth definitely helps.

You need a patent airway for any type of CPR to have any chance of working. Chin lift and jaw thrust are important for both compressions only and compression with breaths.

Source: I’m an attending anaesthesiologist and have resuscitated more people than I would like to count.

> The device itself plays recorded instructions and itself conducts diagnostic tests to determine whether or not it should be used. If it can't detect a treatable condition it doesn't just blat you with electricity for the sake of it

To expand on this a bit, defibs will only deliver a shock if they detect VF (ventricular fibrillation) or VT (ventricular tachycardia). These are considered shockable rhythms. Both involve malfunction of the electrical conduction system usually due to lacking oxygenated blood supply to the heart muscle itself.

A shock seeks (usually up to 300 joules depending on patient size) to reset the hearts' rhythm so the body's natural pacemaker (called the SA node, positioned in the top-right of the heart) can kick back in. If there's no shockable rhythm, the defib machines will usually instruct you to continue CPR (chest compressions) and then will ask you to stop after a cycle of 30 so it can re-analyze the rhythm. Otherwise CPR must continue until medics arrive. If the defib detect a normal rhythm (sinus rhythm) then that's good news and means the defib has been effective.

Pad placement is very important if you're administering defib. The pads are positioned so that the depolarization travels approximately down the septum of the heart, to emulate the normal electrical cascade.

Note: there are many types of heart malfunctions that can't be remedied by a defib but that doesn't mean you should do nothing. Always do CPR. Always call the emergency services.

Possibly of interest to HNers: It is a common misconception that a defib can bring a heart back from 'flat-lining' (asystole). Hollywood movies don't help. If there is asystole, medics will usually continue CPR until the rhythm changes whild trying to reverse any underlying causes of the heart failure (e.g. massive hemorrhaging or hypothermia).

A 30 Kg object drop from 1 meter onto one's foot will unleash around 300 Joules. The heaviest barbell plate is usually 25 Kg. So 300 Joules is a lots of energy. And I once heard a story, not sure how true it is, that someone put the defrib pads over the thigh and on activation the muscle contract so violently that breaks the bone.

>And I once heard a story, not sure how true it is, that someone put the defrib pads over the thigh and on activation the muscle contract so violently that breaks the bone.

I'm skeptical of this.

for the Americans out here: 30 Kg is ~66lbs 1 meter is about 3 feet

If an adult male (about 150 lbs) jumps off of a kitchen counter (about 3 feet) - each leg will absorb 75 lbs from 3 feet. I have done this many times and even my thin feet bones held the force. I'm pretty sure my thighs (our strongest bones) would be just fine.

They had also administered manual CPR which had kept my brain supplied with oxygen at the cost of two broken ribs

I did CPR on an elderly man I found having a heart attack in an alley in London. He was conscious when I found him. I called 999 and stayed with him. He "died" in front of me (no pulse, breathing, motion, loss of urine control). I did CPR until the ambulance arrived; I remember the sound of breaking ribs very clearly. They used a defib on him and he survived and until I moved away from the area I'd see him walking around from time to time.

Was a slightly odd feeling seeing him because I literally saw him "stop".

Were you scared when you broke his ribs? Of course you'd have to but I'd be too apprehensive to do it properly I think.

I was not at all afraid. I got on with the job and I was so focused that I had no idea that the ambulance had arrived until a crew member touched me.

That's interesting, thank you. It is different to what I would have expected of myself in that position.

> The staff at the UK building I was visiting had a defibrillator in their office and one of them had been on a training course.

I have a Philips HeartStart at home. None of us are high risk (we're not obese, fit), or had family history of heart disease. We just like gadgets, and why take a chance?

The last company I worked as an employee at had defibrillators on every floor. While I had to take diversity training, and sensitivity training, I was never required to take -- or offered -- a class in defibrillator training.

It seems they go around 2000 dollars with some very worn out second hand on Ebay for 400.

Sounds ripe for disruption by a Startup doing either:

- Defibrillators on Lease or

- Crowdfunding prototype ;-)

We bought it new. It’s not the type of thing to take a chance on!

At $work we all (or nearly all) get trained in CPR and the use of a defibrillator, and re-trained (and tested and certificated) every second year. We have a defibrillator (and scissors etc) on site where we can easily find it if it's ever needed.

Defibrilators really should be as ubiquitous as fire extinguishers!

(Also in UK) unless I've just become so accustomed to seeing fire extinguishers that I ignore them, it seems they are, and in some cases even more so. The bus stop near me (not a building, just a metal shelter that maybe 5 people can fit under) has a defib. I think our offices used to as well.

In the US, many housing codes require that every apartment be furnished with a fire extinguisher.

I keep two in my house: one on each floor. (One stays under the kitchen sink.)

Wow, that's quite an experience. Just that much happier to see you posting here!

Thank you! I'm happy to be (still) posting here too :-)

I'll bet. Seriously, that gave me pause to consider a refresher first aid course, it's been 15 years and I haven't had any use for it in all that time but it could make all the difference.

Do it! Do it! Booking the defib course was almost the first thing I did afterwards. That and arrange to meet the people who'd CPR'd me. That was a positive and powerful experience and good for them because they'd been much more traumatised than I was.

I will. Thank you for the very vivid reminder. See also the thread about procrastination...

> See also the thread about procrastination...

Yes. Tomorrow.

Hehe. LOL'd, and now I'm getting all kinds of funny looks.

It's kind of crazy how much we rely on ambulances that most often than not feel like they're too slow.Now i know the feeling of time slowing down due to emotional involvement in the heat of the moment, but that doesn't mean there are not a lot of variables from the person needing help to the nearest 'trained medical expert'.The solution imo can be improved by having both more people know basic medical procedures and also more useful devices around.

> at the cost of two broken ribs

Sorry about the ribs, but I'm glad they were trained well. Proper CPR breaks ribs.

I helped rescue a drowning man once. I pulled him from the water (he had been under a few minutes), and long story short, other folks did the CPR, and later a defib. The man died, but I had the impression his ribs survived.

Very glad to hear your outcome was different.

People also don't realize how difficult CPR is.

I did CPR on an elderly man for almost 10 minutes when I was 22; I was completely exhausted afterward.

I have a similar story.

It was like doing weird cardio, to a rhythm, while panicking that if your form is bad you will kill someone. Oh, and I stopped every couple of seconds to expell my entire breath into his mouth

FYI, in case it ever becomes relevant (hopefully not!), the standards for breath to compression ratios have changed. Last I heard about a decade ago, they had moved to 30:1 (compression:breath).

Turns out it's vastly more important to circulate blood than to give breaths, and additionally many people fail to deliver any breath, as it's trickier.

I appreciate that reminder. And for clearly pointing that out to future readers of this post.

For context, this was before the standards changed. I'm glad the standards reduced the amount of breathing (to make room for more heart pumping). Either way, it wouldn't have made a difference in my situation: the patient had a brain aneurysm with a "<1% chance of survival even it it happened in the ER"

----------------

Also, for future readers:

The probability that an amateur using CPR saves someone's life is 1:10,000

For paramedics, it is 1:1,000

So if your person dies, go easy on yourself and get some therapy