Restart a heart near you
February 6, 2017 12:53 PM   Subscribe

If someone had a heart attack right next to you, could you get to your nearest automated external defibrillator, grab it, and use it within 3-5 minutes of their collapse? More and more, the answer is yes, because of Public Access Defibrillation (PAD) programs (that statement is from 1995; 2015 update to AHA guidelines).

On average, when a person in the US calls 911 because someone's suffered cardiac arrest, emergency medical responders get to the scene in 8-12 minutes (Red Cross) -- but for people suffering cardiac arrest, for every minute defibrillation is delayed, the chance of survival goes down about 7-10% (American Heart Association, PDF). Bystanders (even untrained ones) who use AEDs on victims can save lives; "Application of an AED in communities is associated with nearly a doubling of survival after out-of-hospital cardiac arrest."

But where's your nearest AED? In one French study, of individuals who were about 100 meters from an AED in a public place (train station, city mall and public park), only 16% knew where the closest AED was.

Within the US, for instance, different states have different laws covering PAD programs, and a 2010 review led by the CDC found that many states don't require or encourage key elements of a successful program. Most US states require that PAD participants notify or register an AED, e.g., with state or local emergency medical services, and thus with emergency dispatchers who can direct bystanders to retrieve them. (For instance, Washington, DC has participants register as part of a privately run national AED registry, controlled by Florida-based for-profit company Atrus.) But not all states mandate registry, and those registries often aren't accessible to the public. Now, as more people have smartphones and easy access to maps, apps and websites are springing up to tell you where your nearest AED is -- e.g., MyHeartMap, a crowdsourced registry starting in Philadelphia.

Many PAD programs mandate AED placement in schools and other government buildings -- but out-of-hospital cardiac arrests often happen during nights, evenings, and weekends, such that "One out of every four OHCAs in proximity of an AED occurs when that AED is inaccessible due to lack of 24/7 access." And where do nontraumatic OHCAs when the patients are inside buildings that are open? In Toronto: in chain coffeeshops, chain banks, and chain restaurants, and the same neighborhoods see higher rates of OHCAs over time. With sufficient investment, a network of drones could help.

The American Heart Association also recommends that PAD programs offer Good Samaritan civil immunity to all people involved, and mandate ongoing maintenance and testing (in one study, 33% of community-based AEDs failed testing, including all the AEDs stationed in a library or on a college campus).

Untrained AED users often place the pads poorly. If you take a HeartSaver® First Aid CPR AED course (about 4 hours long), you'll get to place the paddles on a manikin and yell "CLEAR!" before hitting the shock button.

An AED in the US generally costs $1,500-$2,000; charities and governments sometimes offer free or subsidized AEDs to participating sites, or create tax credits.
posted by brainwane (14 comments total) 31 users marked this as a favorite

I took a CPR/AED class this past summer. Our town fire department offered it for free through some sort of state grant. Later they offered a similar first aid class, which I also took. The past couple of years they have given this class to every student at the high school.

The AED demo was pretty cool, and it's amazing how foolproof they have made those devices. They should really be everywhere. Not that I ever want to have to use one, but if I were ever in that position I would hope I'd remain calm enough to do it.

Everybody should take these classes. My wife once performed the Heimlich Maneuver on a a choking teenager. She just happened to be walking by him and noticed his friends laughing at him, thinking he was fake choking. She asked if he was choking, he nodded, and she grabbed him and saved him. Totally random chance. Get some training. You never know when you're going to need to know this stuff.
posted by bondcliff at 1:11 PM on February 6 [9 favorites]

This reminds me of a question I've always had about AEDs: what percentage of heart attacks can even respond to an AED? I always thought the AED was just for defibrillation and not for cardiac arrest. So if someone is having a heart attack, it's not even guaranteed the AED will be useful for their particular problem.
posted by fremen at 2:07 PM on February 6

Fremen: some clarification of terminology. Heart attack, in a general sense, means acute blockage of blood vessels in the heart, which can lead to cardiac arrest. Certain arrythmias of the heart can lead to cardiac arrest independent of a heart attack. AED is for defibrillation in case of cardiac arrest. It would only provide shock if the device detect certain types of abnormal cardiac rhythms (ventricular tachycardia VT or ventricular fibrillation VF) that could be responsive to defibrillation. So your question should really be: what percentages of cardiac arrest is due to VT or VF and therefore potentially reversible with electric shocks given by a AED? It's a good question I am pretty sure the answer is out there somewhere. Don't have time to look it up but I will try later.
posted by Pantalaimon at 2:27 PM on February 6 [8 favorites]

fremen: a good question! Short version: it is high enough that AEDs save a lot of lives, but we still have some work to do to make sure we are all on the same page about shockability.

When a person applies an AED to someone, the AED analyzes the patient's heart rhythm to check whether it'll respond well to shock, and won't defibrillate the patient if shocking won't help.
In recent years, emergency medical services (EMS) recordings of initial cardiac arrest rhythms show a striking decline in the incidence of ventricular tachycardia (VT) or ventricular fibrillation (VF) that may benefit from AED use. Initial VT/VF rhythms accounted for 70% to 80% of cardiac arrests 20 years ago (25), but now constitute only 10% to 30% of arrests (8,25,26). Non-VT/VF arrests (asystole and pulseless electrical rhythms) do not benefit from AEDs, and furthermore, their use may delay life-saving measures such as bystander CPR in such patients.

.... In this report, we use this registry to test the hypothesis that despite the decreasing frequency of VT/VF as an initial rhythm and despite possible delays or errors associated with AED application, cardiac arrest patients who have an AED applied before EMS arrival experience better survival than those without an AED applied.

-- "Survival After Application of Automatic External Defibrillators Before Arrival of the Emergency Medical System", 2010 In that paper, check Table 1, "Characterization of All EMS-Treated Victims and Various Subgroups of Interest", to see the shockability percentage of various categories of patients -- it varies by the situation. And results:
Survival was 9% when CPR was performed before EMS arrival, but an AED was not applied (Group 2). Of the cases in which an AED was applied before EMS arrival (Group 3), 24% (69 of 289) survived, and of those who received a shock from an AED applied before EMS arrival (Group 4), 38% (64 of 170) survived.
And then later in the paper:
We extrapolated survival in the approximately 21 million people in the ROC’s [Resuscitation Outcomes Consortium's] covered area to the entire population of the U.S. and Canada (330 million). We estimate that currently, 474 lives are saved per year by bystander application of an AED to those who experience an OHCA.
Troublingly: "Diagnostic Accuracy of Commercially Available Automated External Defibrillators" notes that different AED models have different algorithms and make different decisions about whether to shock in particular cases! And there might be a sex-linked component, as women suffering cardiac arrest are less likely to present with a shockable rhythm.
posted by brainwane at 2:28 PM on February 6 [8 favorites]

We have a couple in my office building and I know where to find both, although as a 53-year-old man with heart disease working with mainly 20 and 30-somethings, I am the guy most likely to need one, not use one.

We used to only have one, on the first floor, until the staff meeting where the health & safety coordinator mentioned its existence and I said "I'll endeavor to remember to have my next heart attack there."
posted by briank at 3:11 PM on February 6 [3 favorites]

I'm one of several people in our RC plane club that would really like to see us get one for our our flying site. We're fairly remote, have a club base that largely is older, and oh yeah, some of these older folks occasionally make trips out into the surrounding corn fields that at times I've wondered whether they'll make it back. Cost is obviously a factor in this case, but I can't help think at some point we're going to have an incident where we'll wish we'd had one.

My wife did actually have to use one on someone at the school she taught at. In that particular case the aed came back and told her to continue cpr and it didn't shock the person. In that case the person didn't make it.
posted by piper28 at 3:28 PM on February 6 [2 favorites]

When a person applies an AED to someone, the AED analyzes the patient's heart rhythm to check whether it'll respond well to shock, and won't defibrillate the patient if shocking won't help.

Note that even in cases where the AED analyzes the heart rhythm and determines a shock is not advised, it then immediately switches over to an audible CPR coach, giving you a metronome beat to help you maintain the 100 chest compressions that are recommended for effective CPR, including prompts for giving rescue breathing (though some CPR courses have now depreciated that portion of CPR; as always, perform the type of CPR you were trained for).

Having that beat to pace yourself saves you the trouble of having to sing the Bee Gees' Staying Alive in your head to keep time (Or if your instructor was a realist instead of an optimist, Queen's Another One Bites the Dust). And if your compressions have managed to take a stopped heart to a heart with the kind of weak fluttering beat that the shock can correct, the AED is watching for that, ready to tell you it wants you to hit that shock button.
posted by radwolf76 at 5:03 PM on February 6 [10 favorites]

Get trained, encourage others to get trained, and always looks for AED boxes wherever you go. It's like herd immunity when we all have some minimum level of training.
posted by wenestvedt at 5:06 PM on February 6 [6 favorites]

AED boxes are so useful! Having a backup, even a mechanised, LED-lit backup, in the midst of CPR is so psychologically helpful and really eases a lot of decision fatigue and "my hands might be pulp???"

The last AED I trained on provided scissors and a razor -- scissors to cut clothes, a razor to shave hair off the places where the device will sit. Really useful. It's worth checking your AEDs to see if they need battery or restock or even additional stock if they don't provide these two things. Add a pair of scissors, save someone from being scorched by their underwire!
posted by E. Whitehall at 8:17 PM on February 6 [1 favorite]

Well, as long as someone arrests on floors 2 or 4 of my 5 story workplace, we are good. Otherwise I guess I just rock the compression only CPR until someone else gets it.
posted by Samizdata at 2:52 AM on February 7

This is a bit of an aside to the main post but it might be interesting to people who care about AEDs, and especially New York City people like me:

Right now, in New York State, the law says whenever an individual/business/location gets an AED that's meant to also be available for public use, that location/org sends a notification form to the regional EMS council, e.g., NYCREMSCO. So the local EMTs & parademics do at least theoretically have access to this registry. I asked someone who knows a Fire Department of New York dispatcher about this, and he said that when a dispatcher puts in the address of an incident, the computer tells the dispatcher whether the building has an AED, but doesn't tell them where in the building it is -- and, doesn't tell them about nearby AEDs at a different address. (The dispatcher is primarily gonna tell the caller instructions on performing CPR; telling the caller "see if someone can find the AED that is at your address" is secondary to that.)

The most recent publicly available map of New York City AEDs seems to be in this 2006 report (PDF), where Section 3.5 on page 12 (page 17 of PDF) has a coarse-grained map of all registered PAD locations.

Also, I called NYCREMSCO and they said that in order for them to release the PAD registry they need an ok from the state Department of Health. So I'm pursuing that now -- I started by sending a request for the quarterly REMSCO reports but I hope eventually I can help open the PAD registry data. Ideally I would like for New York to have its AEDs registered in MyHeartMap, similar to what the Netherlands has (paid for by the Dutch Red Cross), and accessible via the iPhone app and Android app the MyHeartMap folks made, and to have the data layer of that map available in Google Maps and OpenStreetMap. But of course it would be important to update & invalidate nodes if AEDs became unavailable!

(OpenStreetMap has an emergency tag that can have the value "defibrillator" but you can't get at "where is the nearest AED" via the OSM website, because some people are concerned that in dense areas AEDs would flood the map, and also because they'd have to load the new database schema into the database and that hasn't happened for years.)
posted by brainwane at 4:49 AM on February 7 [1 favorite]

AEDs are potentially good if you know whee they are and have been trained on exactly that model. The idea that they use secret algorithms to decide between life and death for liability reasons is bad.

brainwane, it's only the OSM "Standard" tile layer that chooses not to render AEDs. If you're in an office block with multiple floors, mucking about with a web map is not the best way to save a life, so I understand why the rendering team chooses not to litter the map with icons.
posted by scruss at 5:56 AM on February 7

I work for a defibrillation company. They are indeed awesome.

FWIW, scruss, we cover our butts pretty good with a simple disclaimer: "sorry, this device does not guarantee that the patient's life will be saved." Period. We have entire departments devoted to legal issues and regulatory approval. But yes, better training is needed. We always show people the sad video of Hank Gathers collapsing on the basketball court, with a guy holding a defib nearby, totally not using it, and following Hank as they wheeled him away. It could have saved him.
posted by Melismata at 2:56 PM on February 7

"sorry, this device does not guarantee that the patient's life will be saved."

In fairness, despite how the media likes to depict CPR as Clean, Pretty, and Reliable, in reality it is NONE of those, and the same Non-Guarantee of lifesaving applies there too. You're just adding slight chance to a corpse who has none, and CPR with AED means adding a bigger chance.
posted by radwolf76 at 9:12 PM on February 7 [3 favorites]

« Older a feeling of wanting to punch people when I heard...   |   🚄SHINKANSEN🚅 Newer »

You are not currently logged in. Log in or create a new account to post comments.