Why Me???

[DandyDon]

Keeping my line here organized...

I was basically told that what they are assuming is that my body just dosent get rid of nitrogen as quickly as a normal average person. Their recommendation was to limit myself to 2 dives a day, dive every other day or take a day off in the middle of the week, dive nitrox only on air tables and hang on O2 if it is available. Hard to do when you are a diving professional who runs trips.

So WHO told you that? Yeah, I can see your challenge, but then the hits were amazing too.

I was told by the hyperbaric doctor in Cozumel

Ok, well - I guess you have not talked with DAN or any doctors on SB? I stick with this suggestion...

I wonder if the Cozumel doctor who completed my recompression is an expert on PFOs?

We do have experts in the Dive Medicine and Dr.Deco forums. Have you not discussed this with DAN?

SPECULATION -- I wonder if the "extreme hydration" might have been a factor. -- END SPECULATION.

Last year I attended a highly interesting presentation given by a DAN physician at a marine science conference, in which she presented the most recent data on DCS contributing factors. Amazingly, if these factors turn out to be vindicated by more data (at this point, the data are not conclusive yet and more will be needed), everything we think we know about DCS prevention will be wrong.

According to her presentation, mild exercise before and after diving, mild dehydration, mild hypothermia ALL may actually LOWER the risk of DCS. Go figure.

As I said before, the jury is still out and more research is needed, but she also said that at this point, there were NO DATA WHATSOEVER proving that dehydration is a risk factor for DCS. So most of what we take as dogmatic "knowledge" of diving medicine may in fact be flawed.

Ever since that talk, I still practice good hydration, but I am very careful not to overdo it.

What a post. DAN is continuously studying the subject and it would be amazing to see that published.

 

[diversteve]

---

---

A ScubaBoard Staff Message...

moved to Dive Medicine

---

 

[Rhone Man]

That is pretty mind blowing. If you are diving around 60 feet with a pp02 of just under 1.4 ATA, that is an EAD of, what, 43 feet?

To take a Type 1 hit would strike me as improbable, but to take a Type 2 would seem nearly impossible...

Now the odds of doing it twice...

 

[Bubbletrubble]

I'm sorry to hear about your recent DCS hits. You have every right to feel frustrated. I don't blame you for seeking out an explanation for those hits.

The scientific community still doesn't understand all the factors which modulate DCS risk. We also don't have a very good handle on the magnitude of each factor and how one factor might increase/decrease DCS risk in combination with a subset of factors. Put simply, there's a whole lot we don't know about DCS pathophysiology.

Even with "mild" nitrogen-loading, it's certainly possible for a very small percentage of divers to experience an "unexpected" DCS hit. That speaks to the nature of human physiology and the vagaries of biological phenomena. For whatever reason, your experience appears to be an outlier. Duke Dive Medicine asks some good questions which may be helpful in figuring out the cause.

If I were you, I'd take an inventory of anything you did which was out of the ordinary prior to the DCS hits. FWIW, I viewed your comments about "hydration in an extreme way" and wearing a 7mm wetsuit with a suspicious eye...because, to me, that seems unusual. I realize that lots of local DMs wear 7mm wetsuits in Cozumel, but in my experience not many visiting divers (perhaps not acclimated to the local weather/water conditions?) choose that much exposure protection. At least one study suggests that surface decompression divers who are warm at depth have an increased risk of DCS.

I do believe that the info the treating physician gave you is consistent with current research -- that there appears to be a low correlation between the presence of PFO and minor DCS hits (Type I or even minor neurological cases).

That being said, if you are curious, I don't think it would necessarily be a horrible idea to get tested for a PFO. Before having the test(s) done, you might want to spend some time thinking about what type of interventions (surgical, dive more conservatively, occupational change, etc.) you would pursue given a positive result for the test. You should also be aware that experts speculate 20-30% of the population possess a PFO which persists into adulthood. Nevertheless, DCS risk in the dive population remains very, very low -- the incidence of which is estimated to be 1/10,000 to 1/50,000 dives.

Be patient with your search. It might be helpful to contact Divers Alert Network, get acquainted with a local dive-savvy physician, and perhaps speak to a cardiologist with an understanding of hyperbaric medicine. You might want to try contacting Doug Ebersole (debersole), who is a board member and cardiologist with experience performing PFO closures for divers with a history of DCS hits. Best of luck with everything...

 

[LIdiveGirl]

Absolutely,

Computers Used:
Suunto Vytec DS
Oceanic Pro Plus 2.1

Dive Day 1: 100' for 50 min on 32%
55' for 49 min on 36%
3 hour surface interval
72' for 53 min on 36%

Dive Day 2: 102' for 46 min on 33%
43' for 67 min on 37%
7 hour surface interval
20' for 67 min on Air

Dive Day 3: 134' for 57 min on Air, approx 18 minute deco obligation not violated on suunto, 1 minute obligation on oceanic
50' for 61 min on 37%
7 hour surface interval
44' for 67 min on 33%

Dive Day 4: 99' for 52 min on 33%
60' for 60 min on 36%

Each surface interval in between dives 1 & 2 each day was always over 1:30
The dives were drift diving and very minimal energy used.
I always arrived on the boat with 800-900 psi or greater.

Type I DCS occurred after lunch, after we went back to the room and took a cool shower and began to look over photos. The rash was in the left flank area covering most of the love handle region. It was itchy, painful to the touch and constantly changing in shape and color. The prominent colors were red, purple and blueish. After Table 6 of recompression only a small amount of redness remained with minor pain in the area.

My Type II DCS hit was back in 2005 so I will need to approximate slightly

I did a check out dive off the beach the day we arrived, approx 15-20 feet.

Dive Day 1: Max of 70' for approx 45 min on 32%
Max of 60' for approx 45 min on 32%

Symptoms began showing approximately 3-4 hours after surfacing, after a normal shower and a slight amount of physical exercise.
I will admit I was not drinking enough hydrating fluids on this trip in 2005.
Symptoms presented with pain in the right thigh which gradually worsened as I walked through town.
The symptoms escalated to numbness in the right leg and butt and loss of vision, everything seemed to look like I was underwater without a mask.
The doctor said I had balance issues with my Neuro exam and hyper reflexia
Recompressed Table 6 on the first day, and only 3 hours on day 2.

I stayed out of diving for 1 year after my first DCS experience.

Since 2006, I have done many trips some more, some less involved in depth and deco.

 

[Duke Dive Medicine]

Your first incident sounds more like cutis marmorata, which is often associated with more severe DCS and is sometimes categorized as type II DCS because of that. Type I DCS rash looks more like hives. Your second incident sounds like the symptoms are disproportionate to the dive profile. I think you could make a case for being tested for PFO. Bubbletrubble gave some good advice about that, reiterated below:

Before having the test(s) done, you might want to spend some time thinking about what type of interventions (surgical, dive more conservatively, occupational change, etc.) you would pursue given a positive result for the test. You should also be aware that experts speculate 20-30% of the population possess a PFO which persists into adulthood. Nevertheless, DCS risk in the dive population remains very, very low -- the incidence of which is estimated to be 1/10,000 to 1/50,000 dives.

You may just be better off diving nitrox on an air algorithm or tables, and diving more conservatively.

I'm not sure I agree with your physician's statement that if you had a PFO, every DCS hit would be a bad one. PFO is associated with severe brain DCS and possibly cutis marmorata, but a person with a PFO could certainly experience minor DCS symptoms.

 

[Tortuga68]

SPECULATION -- I wonder if the "extreme hydration" might have been a factor. -- END SPECULATION

Is this related to hyponatremia?

 

[Dr Deco]

Hello LI diveGirl:

PFO Problem

I seriously doubt the statement that “if it was a PFO issue that every DCS hit would be a hard hit.” DCS is not an “all or nothing” event. Gas bubbles passing through a PFO might be few in number or a very large quantity. The result would be different. That is not hard to imagine. As mentioned earlier by others, a large fraction of the population has a PFO [actually about 25%]. A large fraction of divers also have bubbles in the venous return [vena cava] during decompression [about one hour post dive] with the potential for arterialization. Looking at the two together, we do not find many divers with neurological DCS. Were that true, diving would be conducted much differently that it has been.

This is not to say that your DCS event was from arterialization of bubbles through a PFO but that is a reasonable guess. Cutis marmorata has been associated with a PFO. Your user profile indicates that you have made many dives in the past, basically without any incidences of DCS. A PFO does not seem to be a "monster in the shadows" for you.

Exercise

Mild exercise post dive is good because it increases the blood flow to tissues and thus promotes nitrogen gas washout. [Sleeping between dives is the worst case as far as perfusion is concerned. Also, if you are asleep, you would not be aware of a developing DCS problem.] Strenuous exercise, on the other hand, can increase bubble size and number. There are differences of opinion on “strenuous,” but we all understand such activities as climbing ladders, hauling several air tanks, etc.

“Valsalva-like maneuvers” [pulling, straining, coughing, and sneezing] are problematic since they can effect arterialization.

Dr Deco :doctor:

 

[emoreira]

Hi, just a comment, I've read the article :

Diving amongst the stars:
NASA and its contributions to
recreational SCUBA
By Michael R. Powell,
MS, PhD

that appeared in the Tech Diving Magazine # 3. Interesting reading about the effects of exercise after diving and the probability to get a DCS.

 

[emoreira]

duplicated. sorry