Does nitrox make you feel good?

[Doc Harry]

Seriously, this survey might indicate a possibility that fatigue among divers responsive to nitrox might indicate subclinical DCS.

I have wondered long and hard about this possibility. It needs to be seriously considered.

 

[fisherdvm]

I think subclinical DCS might be like the fact that many alzheimer pts and dementia pts have actually suffered small strokes. A recent study noted that nearly 10% of folks between the age of 55 and 65 might have had strokes that were not dianosed or "clinical" enough to be seen by a doc.

In the same way, clinical DCS means that a bubble big enough to cause symptoms that calls for hyperbaric chamber treatment.

You kind of wonder what about all the tiny bubbles - slightly bigger than a capillary, but not big enough to knock out a nerve, or cause joint pain - are doing to the muscles, fat, and bones....

My guess is that your body's immune system sufficiently repair these millions of subclinical embolis - but the end result is the release of inflammatory mediators, interleukins, prostaglandins, interferons, etc. .... These products are likely the cause of fatigue.

The direction of future DCS research and nitrox studies should look not at clinical DCS or visible "bubbles"... But at the indicators of subclinical DCS... which might be nonspecific (ie - fatigue), or indirect (complement level, complement activities, ESR, etc...)...

I think we would be wrong to ignore what seemingly nearly half of the responded have noted...

 

[scubadobadoo]

Actually, it's not impossible and one double blind study was conducted. The results showed no difference. Some people do feel better after diving with nitrox, but it's not the nitrox that makes them feel better, it's their mind that does the trick.

BINGO! The results of this poll scare me, but then again, many people are hooked on things they are convinced will change lives but never will. In regards to feeling less tired, nitrox is a bit like religion. It only helps you if you believe it does and that's not a bad thing I guess. I personally rely more on my diving habits, like slow ascents, to help me feel less tired.

 

[fisherdvm]

BINGO! The results of this poll scare me, but then again, many people are hooked on things they are convinced will change lives but never will. In regards to feeling less tired, nitrox is a bit like religion. It only helps you if you believe it does and that's not a bad thing I guess. I personally rely more on my diving habits, like slow ascents, to help me feel less tired.

You might be right, but you might be wrong. That's the scary part.

Perhaps 30 years from now, and 80 extra pounds later. You might also join the religion - then it might be more believable.

I have always been a skeptic - I don't believe in chiropracty (exercise is better), I don't believe in echinasia (studies and studies disproved it), I don't believe in vitamin E (more of my patients gets rash on it), I don't believe in homeopathy....

However, I can also find that many of the skeptics here might be following the leader too blindly... Too gullable to question the "experts"... How many of us will question the dive tables? None... How many of us will question our dive computers? None....

All I am saying here is, perhaps our divetables and divecomputers might not be conservative enough for, in this survey, up to 59% of the population.

Perhaps by making the dive tables and dive computers more conservatively, perhaps we will find much less people favoring nitrox.

I am certainly not going to be stupid enough to accept everything my divemaster, divinginstructor, or even a "Navy" scuba doc telling his student's.. Especially if the evidence is only ONE singular study consisting of only ELEVEN participipants, not pushed to the limit of the dive table (33 ft, one dive).

 

[fisherdvm]

This was in response to the result of the survey, and my question if the survey might indicate subclinical DCS as the cause of diver fatigue responsive to nitrox.





Dr Deco
Medical Moderator

Status

Profile InfoJoin Date: Sep 2000
Location: Seattle, Washington
StatsPosts: 1,854
Nitrox - - -

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Hello readers:

Fatigue

Fatigue from “subclinical DCS” has been a big question over the years. I personally have a feeling that fatigue might exist post dive, but it does not result from inadequate decompression. My reasons are outlined in the following paragraphs. I am not saying that fatigue is an illusion, just that it is not from decompression gas bubbles.

Decompression Tables

Tables are always tested with human subjects. During the tests, they are always loaded to the maximum allowed. During the laboratory testing of tables with which I had some acquaintance [from saturation dives to the PADI Recreational Dive Planner], I never heard the subjects complain about fatigue. These are more severe dives than a SCUBA diver would perform with respect to gas loading. These extended dives where in a chamber; I might posit that the fatigue [if real] could result from strenuous activity in the water.

Tables always have a certain degree of conservatism built in. If divers were acquiring “subclinical DCS” and were actually close to the severe gas loads, I would actually expect more DCS cases to appear. It does not, in actuality, occur often.

Bubbles

Decompression gas bubbles appear to form/grow more readily in tissues that exhibit movement. Muscle tissue ifs a major generator of decompression bubbles as measured with a Doppler device. Muscle tissue, however, does not elicit signs or symptoms of DCS.

I t is possible to muscle tissue releases something that produces fatigue or lethargy. Tryptophane might be a candidate compound. Laboratory tests have never demonstrated that subjects with many Doppler bubbles complain of fatigue or tiredness.

Gas Comparison

In the one case where air and nitrox were tested in a controlled setting, the dives were not very provocative. It might be difficult to form a conclusion from this study. Others have commented on this.

Placebo effect

This is very powerful. It has been noted by pharmacologists that individuals taking a placebo will often display a very high level of effectiveness and even the same side effects as the drug. This even when they are not actually aware of the side effects. All of this from a sugar pill.

Nitrox might accomplish the same effect.

Dr Deco
__________________

Michael R. Powell, M.S., Ph.D.
"If a man empties his purse into his head, no man can take it away from him. An investment in Knowledge always pays the best Interest." - Benjamin Franklin

 

[bart78660]

We use Nitrox on every dive. When I started using it, it was called the Old Fart Gas and was great for people prone to DCS like Smoker, Overweight, crappy physical condition. These days I am in much better condition..hit the gym several days per week, don't smoke, slightly overweight. I know that using 32% definately leaves me feeling better at the end of the dive day than air.

 

[DonFlorida]

When I took my OW class I also took the Nitrox class. I had exactly two days of diving in a pool on 21% under my belt. My next two class dives were a deep lake and a river float dive. Both on Nitrox. I was shocked at how great I felt. My son who is an avid diver, said yeah you can expect that.

My point is I had no preconceived notions or any idea of the effects that Nitrox would have on me and therefore, I don’t think the placebo effect applied to me. I always use Nitrox now when I dive, and I always feel great after.

 

[KevinG58]

Occasional nitrox user here - I notice no difference in energy levels.
But when I am on a trip that pumps nitrox only, and diving 3 or 4 dives a day, I often have a terrible time sleeping. I feel absolutely wired edit to add: later at night.
I don't recall this happening when I use one or two tanks of nitrox on a 6-pack or a day of shore diving.

 

[happy-diver]

Well I'm sitting here and absorbing Scubaboard on my 65in monitor
finishing the dregs of an O2 bottle, before I return it to the gas shop
and I feel magnificent

 

[stiebs]

Wow! A 16 year-old thread revival! How does one even find such a thread to revive? Go-go gadget search!