AED Use in Diving Emergencies

[Dr. Doug Ebersole]

No. I do not feel an AED is needed as "standard" equipment. The likelihood of it being "life-saving" is extremely low. The purpose of an AED is to shorten the time to defibrillation in the event of a sudden death event -- an event where a couple of minutes difference in time to defibrillation can make a huge difference in survival and quality of life. An AED might be helpful for a sudden death event while onboard a dive boat(extremely unlikely), but is unlikely to be of benefit for an in-water or underwater event due to the prolonged delay there would be in getting the victim back onboard, out of their gear, dried off, and the device applied.

That having been said, if a given dive operation wants to purchase one to have available I am all in favor of it. I just don't think the very small likelihood of it saving a diver's life for the reasons above justifies the expense of "every" dive boat having one.

They make a lot more sense in areas where there are large goups of people -- airports, convention centers, sports stadiums, cruise ships, etc.

Just my 2 cents.

Doug

 

[raftingtigger]

I said my belief is that MOST uses of an AED that could occur on a dive boat, would be from drowning.

An AED, an automated defibrillator, only helps in some very specific heart rhythms. It works in both Ventricular Tachycardia and Ventricular Fibrillation ONLY. When the heart stops from drowning (suffocation in water here) the heart quits because the blood no longer has enough oxygen in it. When the heart stops from a heart attack it is usually because the beating of the heart got electrically disrupted. An AED helps a lot with the latter, but much more rarely with the former. In the former you have to get the blood oxygenated before the heart can start again.

Very quick and dirty explanation.

 

[SC_Hoaty]

An AED, an automated defibrillator, only helps in some very specific heart rhythms. It works in both Ventricular Tachycardia and Ventricular Fibrillation ONLY. When the heart stops from drowning (suffocation in water here) the heart quits because the blood no longer has enough oxygen in it. When the heart stops from a heart attack it is usually because the beating of the heart got electrically disrupted. An AED helps a lot with the latter, but much more rarely with the former. In the former you have to get the blood oxygenated before the heart can start again.

Very quick and dirty explanation.

I was taught that the AED is used to STOP a fibrillating heart, so that CPR would be effective, and that the chest compressions were not being counteracted by the erratic spasms of the heart.

 

[danvolker]

An AED, an automated defibrillator, only helps in some very specific heart rhythms. It works in both Ventricular Tachycardia and Ventricular Fibrillation ONLY. When the heart stops from drowning (suffocation in water here) the heart quits because the blood no longer has enough oxygen in it. When the heart stops from a heart attack it is usually because the beating of the heart got electrically disrupted. An AED helps a lot with the latter, but much more rarely with the former. In the former you have to get the blood oxygenated before the heart can start again.

Very quick and dirty explanation.

What I was referring to, was that if a heart had stopped in a diver on a dive boat, then statistically the cause would be from a drowning event. I have not seen rampant heart attacks occurring on dive boats in Florida, though there have been a number of drownings, where the heart stopped.

As you learned when you took Rescue as part of your DM course, when we pull up a diver that is not breathing, and has no heart beat, cpr by itself is not as effective as an AED, in getting the heart to start again. The book and the instructor indicated this to me, but I would obviously defer to Debersole or TS&M, as medical experts that would potentially have a far more accurate grasp of the truthfulness of this.

I don't believe these drowning events should be allowed--that poor training and poor fitness, and poor judgement was to blame for the drowning event....The solution is to fix one of these actual causes, not to say we need a trauma team on the boat, or an AED, just in case a drowning event occurs--all these divers are SUPPOSED to have been trained well, and all are supposed to be executing a proper dive plan.
At a public swimming beach, where non-swimmers wade into the water, along with heart attack's waiting to happen in couch potatoes out for a swim they can't handle....the life guards have an expectation that they will need to save someone every single day. They hope they won't have to, but the public at the beach, are not trained, are not planning, and they EXPECT to be protected and cared for.

Dive certification is supposed to make each diver competent...and those that are not, should absolutely seek out boats with full medical facilities including AEDs, lifeguards, babysitter-divemansters, and a dive site selection of only the most bathtub-like zero challenge sites. The diver with this lack of skill needs to be aware that they have low skill, and it should be up to them to seek out the boats that cater to them.

Other boats need to be allowed to cater to advanced divers.

Also,the idea of being Politically Correct sickens me. In case that was not obvious

Reckdiver and DD think every boat should buy an AED..Nice of them to decide how to spend other people's money........I think every diver should be be properly trained , and then be at such a low risk for a drowning event, that this discussion would never occur. This is partly on the instructors, and partly on the individual.
The exceptions--the medically unfit diver that appear healthy...this is THEIR responsibility to be aware of their own health, and not to have to rely on the kindness and help and protection of strangers.

In this thread we derailed, the boat in question DID HAVE an AED. It did not help in this case, and only the autopsy will give us any clue what actually occurred.

 

[Reck Diver]

I don't want the boats I use, to be forced to buy something that none of the people I dive with need. This getting to the concept of "mandating"

The friends who come on my boat all drive from there sedentary lives to get there. That is after a huge breakfast of pancakes, gobs of butter, artificial maple syrup, a couple of eggs fried in lard, 1/2 pound of extra-fatty bacon and a couple of cups of coffee with cream and sugar, topped off by a couple of Lucky Strikes. After a couple of pumps on the chest, they manage to get up, though they can no longer see their feet when standing (D.D. ...that's why they don't bowl any more). With the help of a generous application of Crisco to their flanks, they squeeze in to their cars.

None of them plan to have a violent car wreck on the way over, but they all have dual air bags which cost, oddly enough cost about the same as an AED. Hopefully they will have those airbags in brand-new unused condition until the day they part with the vehicle. Even though they are legally required to wear seat belts and shoulder restraints, they still have airbags, which are mandated for safety. And no thought or consideration is given to whether or not it is a financial hardship. I'm guessing you own a couple that you hope you never need.

But I guess everyone asks a for government mandate somewhere along the line, whether it is needed or not. After all it was you who wanted The County Government to mandate making the area around Phil Foster Park declared "The Blue Heron Bridge Marine Sanctuary." That included an additional mandate prohibiting tropical fish collection and possibly even a third which would mandate where instructors and students could dive.

 

[danvolker]

I like a government mandate that proclaims burglary and theft as illegal. I like a government mandate that if an intruder is found in your house, you can legally shoot them....they deserve to be shot( granted the reason is self defense or protection of others in the house). These are basic laws to deal with the anti-social tendencies of a percentage of people in a general population.
The desire for a mandate to prevent the killing of animals in a "petting Zoo" falls close to the same in my mind.

This is NOTHING like a mandate about the government needing to protect me or you from doing dumb things, or being unsafe. It should be up to us to make choices that will keep us safe, and it should not be the job of big brother to give us safety rules in our various forms of recreation.

 

[dumpsterDiver]

Dan: I never expressed the opinion that every charter boat should have an AED on it. I only said that my one friend carries one on his boat. It seems that you are trying to mischaracterize my statements.
In the post below you say the following:

If you are taking out people really in danger of a cardiac event, you really DO need to be planning safety measures like an AED on any boat you book on. Personally, those are not the people I am diving with, and they should not even be on the same boat, because the dive sites WE will like will have big currents, and challenges that would be foolish for the cardiac challenged to be dealing with. Of course, it would be poor judgement for you to take a person likely to have a cardiac event, into a really challenging current or dive site...the AED as a solution to having medically challenged divers with you is an inferior solution to keeping these divers out of the water.

I noticed in another post, the one below, you make this statement:

For Monster current dives, I have yet to use the Excellerators to get a fair comparison with the DiveR's...the Mispah dive has insane current, likely over 4mph on the bottom. I was able to do every thing I wanted with the diveR's, where as pretty much everyone else on the trip had to hide much more.
http://www.scubaboard.com/forums/force-fin/429227-ok-dan-volker-2.html#post6478523



So....I was wondering….We don’t yet know if the 66-yr old diverwho died had a cardiac event, but we have heard that the heart stimulation devicewas used on him in this tragic situation. Based on your comments above, if we do find that the fatality was associated with a cardiac event, do you feel that the operator used “poor judgement” (sic) in taking the 66 yr old man on the Mispah dive site (with the "insane" currents and all)?

 

[danvolker]

First, I believe the operator should assume that no diver on the boat is a potential cardiac event..I doubt Debersole or TS&M would want to have to reliably determine who was a cardiac risk and who was not by appearance or age. This is not the job for the captain of a boat....Now, if someone is stuggling to walk and looks like they just had a stroke or something, that's a different story, and not what you were referring to.
As to the age, I know several 60 to 70 year old cyclists that could ride circles around you on a 50 mile bike ride, and if we put fins on them, in all liklihood outswim you too....it is not so much as an age issue, it is how much your train your cardio and your muscles, or how long has it been since you stopped training.

If a diver is a potential cardiac event, and they know it, they should tell the operator....in which case the operator would then refuse to take them diving..in all probability.

As to the Mispah, you are certainly aware that often this wreck has no currents, though sometimes it can scream. It is usually apparent if it is running fast, but not always, as we sometimes have bottom currents that do not match the surface currents. In the post you refer to, in context, this was an unusual day...A day when the current was ripping at the Mispah, but where there was no current at all 7 miles south....Also kind of a strange scenario...of course you did not want to place my post in context, and you know very well I was not saying that the Mispah is always a site with a ripping current. Usually it is an easy wreck dive, good for new divers ready for a wreck dive.

If a diver fibs their way into diving with a serious heart condition, and finds themself dropped on a wreck with a huge current, then the smart course for them would be to just ignore the wreck, and do a leisurely drift back up to the surface, and get picked up with no effort. That is one of the beauties of drift diving. Again, divers need to take personal responsibility for their health and training level. The diver in question had over 50 dives, and was with an instructor, and in a class...the instructor chose the dive site, and it was not up to the captain...and, it is lame of you to make such foolish assertions.

In the plus collum for you, your comment about the Keys trip was pretty funny, and you did get me chuckling with that one....

 

[raftingtigger]

I was taught that the AED is used to STOP a fibrillating heart, so that CPR would be effective, and that the chest compressions were not being counteracted by the erratic spasms of the heart.

Partly right. The defibrillator shocks the heart into stopping all electrically activity -- in the hopes that the heart's own pacemaker cells can reassert control and resume an effective blood pumping beat. A heart that has no electrical activity left (asystole) is not shockable, nor is a heart that has proper electrical activity (pulseless electrical activity or PEA) but no ability to convert that electrical activity into pumping action.

The function of the shock is not to stop the heart so that CPR can be more effective. It is to give the heart's own pacemaker a chance to resume control so you no longer need to perform CPR.

Again this is a very quick and simplistic explanation. In short, if you have someone unconscious and apparently not breathing and you have an AED immediately available - hook it up and turn it on and follow the instructions. Begin compressions ASAP (must be out of the water). Doing both steps in parallel is best. However you are more likely to have a positive outcome with a witnessed heart attack than with a drowning scuba diver.

 

[TSandM]

Just to do a very quick overview of the utility of defibrillators:

The heart has two important components to its function. One is electrical and the other is mechanical, or pumping. The electrical part makes sure that the heart beats at a rate that allows effective pumping, and makes sure the different chambers of the heart contract in the proper sequence, to make blood flow efficient. If the electrical signal is scrambled or confused, the heart may beat too fast to pump blood, or may just quiver. But even if the electrical procedures are going as they ought, if the heart muscle can't contract because it's damaged, there won't be enough (or sometimes any) blood flow.

Even if blood is flowing, it has to have oxygen in it, and that requires functioning lungs and air moving in and out of them. And if the brain is deprived of oxygen for too long -- more than a few minutes -- the brain may not be driving the diaphragm and chest muscles to breathe.

So, all a defibrillator does is correct abnormal electrical activity in the heart. If there is NO electrical activity (not uncommon with hypoxic arrests, as with drowning) a defibrillator will do nothing. If the muscle isn't working (not uncommon with massive heart attacks) you can correct the electrical activity, sometimes, but it won't help because no blood will flow anyway. If the brain has quit working, you may get circulation restored, but the outcome won't change.

Immediate defibrillation is the best and most effective treatment for ventricular fibrillation or ventricular tachycardia, two rhythms seen in heart attacks which are very deadly. The longer the shock is delayed from the onset, the less effective it is. As debersole observes, the majority of people who have heart attacks in the water have quite a long period before they can be removed from the water and gotten to a stable surface, whether that is land or a boat. Admittedly, administration of shock may be the BEST way to treat such a patient -- but I can't estimate the number of people who, once they have been gotten to the boat, are going to be good candidates for shock with a likely positive outcome (meaning discharge from the hospital with good neurologic function).

Drowning victims who have reached the point of Vfib or Vtach are in a world of hurt. Hypoxic arrests have a very poor survival rate, and although we have all heard the stories of people drowning in cold water who have survived long periods, it requires that the person have been IN the cold water for a long time before the arrest occurs, so they are good and cold before their circulation stops.

I guess my reason for writing this is to let people know what the actual utility of an AED is. It's not a panacea; it won't save everyone who has had a cardiac arrest from a diving incident. It WILL save a certain percentage of people who have a primary cardiac event, but only if they are treated quite promptly. If one is available, it is not at all unreasonable to attach it to anyone without a pulse. You may save some people that way. But regarding an AED as on the same level as oxygen or life vests on a boat is, I think, attaching too much importance to a piece of equipment whose applications are somewhat limited.