Why so many deaths? (DAN article)

This forum is provided for the further edification of our club members seeking to improve their knowledge and diving skills. (recreational diving only)
Post Reply
User avatar
Gregp
Frequent Bubbler
Posts: 48
Joined: Mon Mar 03, 2014 6:10 pm

Why so many deaths? (DAN article)

Post by Gregp »

Whenever we hear of or lose a member diving, it hurts us and shakes us to our core. It seems that this has happened with too much frequency here in the PNW. Sometimes, it might scare us enough to think about giving up the sport.

I've been thinking about what can we do to decrease these deaths? Whenever I've thought about the reasons why, I thought initially it was primarily due to equipment failure, lack of air, DCS, or maybe even CVD (cardiovascular disease).

Well, I just read a great article by DAN http://www.diversalertnetwork.org/files ... Causes.pdf and would like share some insight which will help us make better and safer diving decisions. I was highly surprised by what I learned. Note that the study was for OC diving.

The most prominent trigger for diving fatalities was lack of air at 41%. Entrapment as a trigger was 20%, equipment problems were 15%, and rough water was 11%. What does this mean? To me, it suggests that we are wise to place more education on air supply/consumption, getting untangled, and diving with a buddy to aid when one of us needs help. How many agencies really focus on this type of prevention? I don't know, but I suspect that unless your doing tech dives you might not get this type of education. I never got it with my OW/AOW training.

What's going to really disable a person that well lead to an injury? Well, 55% in DAN's study were due to an emergency ascent, 27% due to insufficient gas, and 13% to buoyancy problems. I can imagine how easy it is for someone to get scared when they're out of air and feel the need to hold their breath to the surface - this can easily lead to an arterial gas embolism (AGE). Maybe we need a little more education in managing and controlling our ascents and with different equipment malfunctions?

I think it gets interesting at looking at the injury which leads to the bad outcome: 33% of fatalities were to do lack of oxygen (asphyxia), 29% for an AGE, and 26% for cardiac incidents. These three injuries lead to 88% of all deaths, WOW! I thought there would be more injuries here. Note that DCS only accounted for a 2.5% of the deaths, which is where so much emphasis is placed. Do we need to change our viewpoint?? I think so!

How much do the fatality odds increase with each major injury?
- For Asyphyxia: entrapment increases the odds by 30 times and insufficient air by 15.9 times.
- For AGE: emergency ascent increases the odds by 30 times.
- For a Cardiac problem: CVD (cardiovascular disease) increases the odds by >10.5 times and being >40yrs of age the odds go up 5.9 times. Cardiac problems is a huge problem not just for divers, as 1 in 3 will be succumbed to this disease.

So what can we do??
- learn better air management and be conservative with air.
- learn how to get and help others get untangled
- be an aware diver
- dive with a buddy - DAN notes that 57% of those in the study begun their dive with a buddy and were separated.
- learn and practice emergency ascent procedures and controlling them.
- get checked out CVD risks, if you have risks get them managed by a physician, or better yet a functional medicine/nutrition expert who can uncover the many underlying causes and address them. If you don't have someone, PM me and I can either find one for you or get you the testing you need as I frequently order blood tests and EKG's for my chiropractic and nutritional patients.
- definitely don't dive if you have CVD symptoms as 60% of those had lack of breath, chest pain, or didn't feel well before or during diving. (maybe we should add this to our buddy checks)

I hope this spurs some discussions and challenges us to improve our safety procedures.
User avatar
Jeremy
I've Got Gills
Posts: 1547
Joined: Sat Jul 16, 2011 3:25 pm

Re: Why so many deaths? (DAN article)

Post by Jeremy »

Great post, thank you for sharing.

Seems like out of gas and emergency ascent fatalities are close to the same thing and would account for well over half of the fatalities. The buddy system would be an effective prevention of this bit that assumes you dive in such a way that you are always in a position to render rapid assistance and that you practice in such a way that the response is solid and automatic.
User avatar
Grateful Diver
I've Got Gills
Posts: 5322
Joined: Mon May 15, 2006 7:52 pm

Re: Why so many deaths? (DAN article)

Post by Grateful Diver »

That's why I've been doing gas management seminars for the past 10 years. And it's why that is also one of the major modules in my AOW class.

It's why I place so much emphasis on buddy skills at the AOW level ... it's one thing to tell people they should dive with a buddy, and something else altogether to teach them how to do it.

Agencies don't train divers ... instructors do. And there's nothing preventing any instructor from teaching this stuff. The reason it doesn't usually get taught at the recreational level is because of the prevalent belief that it isn't needed (despite the statistics you just quoted saying otherwise).

I keep hearing people say that all that's sufficient is to monitor your air supply and end the dive with 500 psi. If that approach is so effective, why do so many people run out of air? It is, after all, a 100% preventable problem ...

... Bob (Grateful Diver)
Threats and ultimatums are never the best answer. Public humiliation via Photoshop is always better - airsix

Come visit me at http://www.nwgratefuldiver.com/
User avatar
Gregp
Frequent Bubbler
Posts: 48
Joined: Mon Mar 03, 2014 6:10 pm

Re: Why so many deaths? (DAN article)

Post by Gregp »

Jeremy wrote:Seems like out of gas and emergency ascent fatalities are close to the same thing and would account for well over half of the fatalities. The buddy system would be an effective prevention of this bit that assumes you dive in such a way that you are always in a position to render rapid assistance and that you practice in such a way that the response is solid and automatic.
Yes, I agree Jeremy!
User avatar
BillZ
Aquanaut
Posts: 687
Joined: Mon Mar 03, 2008 12:23 am

Re: Why so many deaths? (DAN article)

Post by BillZ »

From what I've observed the root cause of most diving accidents is stress leading to panic. Stress can be caused by several factors such as doing dives that are above your training and skill level, equipment issues or just having a bad day and not being in the right mindset to be diving. IMHO the most critical skill you need to be a safe diver is self awareness, which I would define as the ability to identify stress within yourself and then the guts to call a dive when you're not feeling right.

The second thing I see is a general lack of physical fitness in divers. Diving is unique in that you don't need to be in shape to participate or to even be really good at the sport, but if you're unhealthy or out of shape you're putting a huge strain on your body and drastically increasing your chances of a physiological issue underwater. Also being out of shape means you are less likely to be able to handle issues with yourself, your buddy or your team as they arise.
User avatar
Desert Diver
Extreme Diving Machine
Posts: 472
Joined: Tue May 22, 2012 9:20 pm

Re: Why so many deaths? (DAN article)

Post by Desert Diver »

I believe that low on air triggers many deaths but I question how many actually die from that. We have seen a guy panic when he realized his air was low and instead of heading up, he still had 300 lb, he went kind of loco trying to grab my wife's primary. We had only been down about 15 minutes, there were no decompression issues. I still think that panic is what kills the most. It causes AGE, heart attacks, drownings when the people have reached the surface and fail to establish buoyancy and other issues. I'm certainly not immune to panic but I believe that thinking through what I might have to face and deciding what I will do if I face it is a good practice. Too many people are just there to see the pretty fishies and have never thought about what to do in bad situations. How many bodies have been found on the bottom with weights intact who had reached the surface and then sunk? It's a bunch.
User avatar
LCF
I've Got Gills
Posts: 5697
Joined: Tue May 30, 2006 5:05 pm

Re: Why so many deaths? (DAN article)

Post by LCF »

An ounce of prevention is worth a pound of cure . . . which is why Peter teaches gas management in every class beyond OW, and is overjoyed that the new PADI OW class includes some gas management concepts!

Catastrophic equipment failures are extremely rare, even here in our cold water. The cause of out of gas emergencies is almost always a diver who has either taken too little gas with him for the dive he proposes, or has failed to monitor his gas (or both). Education on how to predict the required gas, and how to compare the proposed dive to the gas supply available, can help a great deal, even if it's only to make divers aware that dives which seem quite benign (60 feet for 50 minutes, anybody? We were doing that problem in the OW class last night) can have unexpectedly high gas requirements.

But gas management isn't enough by itself. The other half of the problem is that divers get out of their classes (and not many take a lot of them) and never practice the emergency procedures they were taught until the emergency occurs. When was the last time any of us took our mask off and put it back on in Puget Sound? I'm as guilty as anybody else on this! How many times have those of you who aren't instructional staff done an air-sharing ascent with a buddy, to make sure you can control it well? I know of one death here that occurred because, although the divers established a competent air-share, they fell apart on the subsequent ascent.

I think, in addition to community-building, one of the biggest values of forums like this one is to help raise consciousness about these topics. For everyone who posts on a forum, there are multiple lurkers, and they read threads like this one. If this type of thing helps raise awareness that there are TOOLS out there to help prevent problems, and to deal with them if they do occur, we may help save lives here.
"Sometimes, when your world is going sideways, the second best thing to everything working out right, is knowing you are loved..." ljjames
User avatar
GearHead
Submariner
Posts: 517
Joined: Mon Dec 03, 2012 10:32 am

Re: Why so many deaths? (DAN article)

Post by GearHead »

I believe another factor to mention in this discussion is maintaining good physical health. in the more recent fatalities, I haven't seen any indication of equipment failure or running out of gas. Rather, the victims seemed fine until they either became unresponsive, or began a return to shore and were found unconscious later on the surface. If I am reading this correctly, it would appear that cardiac events might have been the cause of death.

I don't wish to engage in speculation, but simply want to emphasize the importance of being physically fit while conducting activity underwater. In that environment, stressful events that would have been benign or at least survivable on land can easily become fatal.
User avatar
Gregp
Frequent Bubbler
Posts: 48
Joined: Mon Mar 03, 2014 6:10 pm

Re: Why so many deaths? (DAN article)

Post by Gregp »

As a background, the DAN study included investigating 947 diving fatalities from 1992-2003.

One thing I didn't provide earlier were the statistics for cause of death (COD) which was determined by the medical examiner:
- 70% were due to drowning
- 14% due to arterial gas embolism
- 26% to cardiac incidents.

The authors decided that it was more relevant to place more focus on the events leading up to the Injuries because the COD was often secondary. If I can repeat the injuries that lead to the fatalities, they are:
- 33% due to lack of oxygen (asphyxia)
- 29% for AGEs
- 26% for cardiac incidents

In regards to low air and people actually dying from it, DAN stated that
- For Asphyxia (33% of fatalities), it accounted for 32% being the trigger. That would be roughly 10.5% of total deaths.
- For an AGE (29% of fatalities), insufficient air accounted for being 63% of the triggers. This would be about 18% of the deaths.
For low air, 28.5% of the cases were the trigger.

In regards to entrapment:
- Asphyxia (33% of deaths), it accounted for 40% being the trigger. That would be roughly 13.2% of total deaths.
- For an AGE (29%), insufficient air accounted for being 9% of the triggers. This would be about 2.6% of the deaths.
For entrapment, 15.8% of the cases were the trigger.

If we had a class, that addressed both low air and entrapment and we were able to eliminate all fatalities, that could possibly decrease the deaths by as much as 44%. That would be huge! I suspect that there are many instructors already doing this.
User avatar
CaptnJack
I've Got Gills
Posts: 7776
Joined: Fri Jul 07, 2006 2:29 pm

Re: Why so many deaths? (DAN article)

Post by CaptnJack »

"entrapment" AKA cave or wreck diving without training and/or not following training protocols for overhead diving
Also getting stuck in/on grates or openings due to delta-P, or in lay terminology suction. Think irrigation canal pipes and dam structures.

At a certain level you can't fix stupid and we all know of multiple deaths over the years due to plain old bullheaded stupidity. Diving a relative Mount Everest of caves (eagle's nest) without even open water scuba training nevermind actual cave, trimix, and decompression training. A new diver trying out new gear solo. Or bounce diving to 200ft on AL80s of air for thrills. There's no end to potential poor choices out there.
Sounder wrote:Under normal circumstances, I would never tell another man how to shave his balls... but this device should not be kept secret.
User avatar
Gregp
Frequent Bubbler
Posts: 48
Joined: Mon Mar 03, 2014 6:10 pm

Re: Why so many deaths? (DAN article)

Post by Gregp »

BillZ wrote:From what I've observed the root cause of most diving accidents is stress leading to panic. Stress can be caused by several factors such as doing dives that are above your training and skill level, equipment issues or just having a bad day and not being in the right mindset to be diving. IMHO the most critical skill you need to be a safe diver is self awareness, which I would define as the ability to identify stress within yourself and then the guts to call a dive when you're not feeling right.
Hi BillZ, Yes I'm inclined to think that panic is involved in more cases. DAN reported in the study that distress/panic was difficult to assess. That's probably why we aren't seeing it with more significant in the research article.
Post Reply