Suffered DCS for the first time and terrified to dive again

[vladimir]

So while over-hydration probably does happen a bit more often than most people would think, it is indeed generally a very low probability event that tends to require special conditions...

...like a "Hold Your Wee for a Wii" contest:

Too High a Price for a Wii - NYTimes.com

 

[Crush]

DCS is not a badge of shame, it's an athletic injury.

I have spoken to about five OW instructors and one cave diving instructor about DCI. Bear this small sample size in mind when you read the following:

The one cave diver that I spoke with about DCI had the attitude "it happens" and "that is the price of diving." Perhaps he meant diving on the edge - I am not sure. It was not a badge of courage, but it was not a mark of shame. Perhaps it was a dirty little secret? To him, skin bends was a warning that meant that it was time to take a few days off diving.

All five of the OW instructors that I spoke with felt that getting bent was a stigma and shameful. There was no recognition of "unanticipated" (or "unexpected" or "undeserved" or whatever other adjective you want to use) DCI.

I am glad to read your statement, Duke Dive Medicine.

 

[jbird71]

I realize you are being a bit flippant in some of your posts--and perhaps these--but I think it's important to point out that the overwhelming majority of divers never break their "DCS cherry."

I apologize if I came off poorly, that was not my intent. Too often someone's first DCS incident is fatal, so i consider myself lucky. From this experience I have learned a lot about the warning signs, things to look for, and what I need to do medically to make sure that I can dive safe.

 

[jbird71]

Scuba diving (like a lot of sports), attracts adrenaline junkies. A friend's brother got his kicks taking Air down 280 feet. It also attracts a lot of very safety conscious people. From my experience neither side understands each other well.

 

[Mr Carcharodon]

I'd second the suggestion to add safety stops or 1 to 2 minute stops at 9, 6 and 3 msw. You can lower your risk either by not coming close to the NDL in the first place, or by decompressing on the way back up. Doubling the length of the shallow stops is generally recommended if surface intervals are less than a hour. And you can add even more to the shallow time if you know you have risk factors such as being cold, tired dehydrated, short surface interval, a history of DCS, etc.

I believe (and will no doubt be corrected if I am wrong) that the reason being cold is a risk factor is that it drives the level of blood flow to the peripheral tissues of the body. The rate of blood flow drives the rate of loading and unloading those tissues. So as you get cold nitrogen is unloaded more slowly than normally during the ascent. After getting out of the water and warming up circulation increases and unloading speeds up. And of course since you are on the surface the pressure gradient is high. The high pressure gradient together with having dissolved gas is what drives bubble formation. Getting cold during the dive and then warming up on the surface is similar to a rapid ascent. Anyway doing the shallow stops, conditions permitting, is a good idea.

 

[Mr Carcharodon]

Jbird71,

What do you think drove your rapid ascent from the second dive?

Do you think you were under weighted? Out of practice on the ascents? Or maybe just not paying attention at that point in time?

 

[DandyDon]

You might consider getting checked for a PFO. Simply getting checked doesn't imply getting a PFO repaired, even if it is discovered that you have one.

I know that you are much more experienced at diving than I, as are several others here, but have you read the latest DAN article on that? Alert Diver Online Maybe I could appreciate the idea of exploring that more if it was a totally unexplained hit, but especially looking at that second dive...

It was my first day of diving.

Traveling to Coz is a long, dry experience for me - driving to airport, hustle & hassle, flying is a plane with almost no humidity in the air (none other than what comes off of passengers; bone dry air pumped in), and so forth - plus not wanting to stand in line for the tiny, messy lavatory on planes, so the first evening and morning before diving I really work at hydration. I understand that this can be overdone, but not likely.

How well do you know your computer?

Your idea of a refresher course is maybe not as important as studying your computer and knowing well what it takes to make it happy. The graphs you posted are informative but not as inclusive as the earlier examples - can't see what the N2 loading was?

I don't know what DAN studies say about type II diabetics, I know that diving is not prohibited, but can't that reduce circulation, too - along with dehydration...??

Dr.V, any comments on that...??

I do hope I am not being too blunt. No one screws up more than me diving at times, it happens, but I would like to see you enjoy it more conservatively.

 

[Crush]

I'd second the suggestion to add safety stops or 1 to 2 minute stops at 9, 6 and 3 msw. You can lower your risk either by not coming close to the NDL in the first place, or by decompressing on the way back up. Doubling the length of the shallow stops is generally recommended if surface intervals are less than a hour. And you can add even more to the shallow time if you know you have risk factors such as being cold, tired dehydrated, short surface interval, a history of DCS, etc.

I believe (and will no doubt be corrected if I am wrong) that the reason being cold is a risk factor is that it drives the level of blood flow to the peripheral tissues of the body. The rate of blood flow drives the rate of loading and unloading those tissues. So as you get cold nitrogen is unloaded more slowly than normally during the ascent. After getting out of the water and warming up circulation increases and unloading speeds up. And of course since you are on the surface the pressure gradient is high. The high pressure gradient together with having dissolved gas is what drives bubble formation. Getting cold during the dive and then warming up on the surface is similar to a rapid ascent. Anyway doing the shallow stops, conditions permitting, is a good idea.

My knowledge of cold water complicating DCI is imperfect. What little I know is seen here: http://www.scubaboard.com/forums/5650197-post23.html

Summary:

• start a dive cold and end it cold = OK
• start a dive cold and end it warm = OK
• start a dive warm and end it cold = possibly not OK

Current models for N2 uptake assume typical perfusion (i.e., normal rates of blood flow into and out of tissues). When you start a dive warm but end it cold you have had normal N2 uptake into tissues on the way down (while you are warm), but on the way up the cooling has resulted in your off-gassing slower than models predict because the cooling has caused your blood flow to peripheral tissues (i.e., perfusion) to decrease. In a sense, this is the same as surfacing rapidly. Getting chilled is not going to guarantee DCI - I get pretty cool on many dives. The trick is to hydrate, not get to the point of shivering, don't "red-line" your computer (wrt NDL) and simply take it easy.

 

[TSandM]

I looked at your profiles, and the one thing that really stood out for me was ascent rate.

When I began diving, I used the 30 fpm ascent (although I seriously doubt my ascents were that precisely controlled) with a safety stop. Subsequently, I was introduced to the concept of a more rapid ascent in the deep part of the dive, and a much slower ascent as one approached the surface. Since I adopted that strategy, I have not had the fatigue from diving that I had before, and there are folks who believe that fatigue IS a marker of decompression stress, including people who do research in decompression.

Both of your dives were significant dives, in terms of the depth-time product for nitrogen loading, and both involved fairly rapid ascents -- and the second one didn't include any kind of stop. I think, if you adopted something like the minimum deco ascent (which is 30 fpm to half maximal depth, and 10 fpm thereafter, and a very, very slow ascent from 10 feet to the surface) you might avoid symptoms in the future.

Thank you VERY much for posting your experience and your profiles. Having this kind of information go public is a great way for others to learn from your misfortune.

 

[scubadiver888]

IMHO, it's fine to make a little light of it after the fact considering the good outcome. I'll emphasize again that I think you did far more right here than you did wrong. I'll be back in clinic on Wednesday. If you'd like, I can look in our database then and see if I can find a diving physician close to you, unless somebody here knows of one in Toronto and can provide the info.

The best thing for jbird71 to do is go to Toronto General Hospital. They have a hyberbaric department and someone is on-call 24 hours a day. The best doctors would be working during the day; considering it is a follow-up I'd pop in during the day.

Even if they aren't the correct hospital, the University Health Network links all the hospitals in the downtown core (there are over a dozen).