Muscle injury from mild untreated DCS?

[Dr Deco]

Hello cudachaser:

Lactic Acid

I do not know where the instruction obtains his information. Lactic acid is formed from glucose in muscle tissue when work, especially anaerobic (no oxygen) work, is being performed. [This is, for example, in the case of a sprinter and anaerobic glycolysis.]

These individuals might have some pain until the lactic acid buildup is washed out by the blood; this is usually 30 to 60 minutes. [This pain is entirely different from delayed onset muscle soreness from microtrauma and inflammation.] Decompression bubbles are not numerous enough to cause this problem, or, if they do, it is masked by CNS problems.

Any paper on “Compartment DCS” I would need to see, as there is no term such as that used by professional barophysiologists in the manner suggested here.

Doppler

Some references below indicate the poor relationship of bubbles (mostly from muscle tissue) to DCS pain. I tried to find some from the US Air Force Laboratory, but they as so displeased with Doppler and seldom comment on it anymore. They consider even Spencer Grade IV as to have very little relationship to DCS outcomes, with the excetion of neurological ones.

Compartment Syndromes

These problems arise when edema forms in tissue and swelling eventually encroaches into the vascular space shutting down blood flow. It often must be treated surgically to reduce the pressure and allow the reinstitution of blood flow. It is sometimes helped by hyperbaric oxygen.

I am not aware of divers acquiring a “compartment syndrome” in the absence of a something like crush injury.

Dr Deco :doctor:


References

Gardette B. Correlation between decompression sickness and circulating bubbles in 232
divers. Undersea Biomed Res. 1979 Mar;6(1):99-107.

Powell MR, Thoma W, Fust HD, Cabarrou P. Gas phase formation and Doppler monitoring during decompression with elevated oxygen. Undersea Biomed Res. 1983 Sep;10(3):217-24.

Conkin J, Foster PP, Powell MR, Waligora JM. Relationship of the time course of venous gas bubbles to altitude decompression illness. Undersea Hyperb Med. 1996 Sep;23(3):141-9.

Dervay JP, Powell MR, Butler B, Fife CE. The effect of exercise and rest duration on the generation of venous gas bubbles at altitude. Aviat Space Environ Med. 2002 Jan;73(1):22-7.

 

[Saturation]

I concur fully with Dr. D.

 

[DocVikingo]

Hi Dr Deco,

May I take it from your earlier statement, "What is so surprising is that even when many decompression gas bubbles are detected, the individual notices nothing. There is generally no pain, fatigue, lethargy – nothing. In fact, even with Grade IV bubbles on the Spencer-Johanson grading scale, there is not even the notice [symptoms] of joint pain DCS [it occurs in less than 50% of the instances]," that no damage is being done to muscle by these bubbles when they do not reach the level required to precipitate AGE or severe DCS?

Thanks,

Doc

 

[Saturation]

Hi DV:

Let me take a stab at answering what you request of Dr. D. Bubble grades are correlated with DCS but not 1:1, I think it has a correlation coefficient more around 0.6 than 0.8 or so with quite a wide confidence interval. In this study sensitivity and specificity are calculated for bubble grades against clinical DCS:

http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?itool=abstractplus&db=pubmed&cmd=Retrieve&dopt=abstractplus&list_uids=9125093

IMHO, ultimately what also matters is the length of the persistence of the bubbles, more than just its presence. high grade bubbles are common in He mixes but clear quickly, a Grade IV from N2 is likely to be more concerning, and there is little data on that as I know.

 

[Bill51]

Hello cudachaser:

Lactic Acid

I do not know where the instruction obtains his information. Lactic acid is formed from glucose in muscle tissue when work, especially anaerobic (no oxygen) work, is being performed. [This is, for example, in the case of a sprinter and anaerobic glycolysis.]

These individuals might have some pain until the lactic acid buildup is washed out by the blood; this is usually 30 to 60 minutes. [This pain is entirely different from delayed onset muscle soreness from microtrauma and inflammation.] Decompression bubbles are not numerous enough to cause this problem, or, if they do, it is masked by CNS problems.

The statement was actually that it appears in some cases the body “thinks” microbubbles in muscle tissue is lactic acid, not that it is or creates it in any way. There was a paper about 10 years ago that I think (if my old memory serves me) came from NOAA or NASA discussing fatigue after dives (or on space walks) where it was mentioned that there was a similar physiological response to microbubbles in muscle tissue and lactic acid buildup in the way they are both washed out of the tissue. The hypothesis I remember was something to the effect that microbubbles could compete with lactic acid in being removed from the tissue and prolong muscle fatigue.

 

[Dr Deco]

Hello Bill51 :

There has been a thought that “silent bubbles” in muscle tissue could be a cause of post-dive fatigue. In laboratory tests where bubbles are monitored by Doppler ultrasound, subjects do not seem to indicate fatigue associated with bubbles. That is, they do not report a problem while at the same time they do not know their bubble grade. It is a “blind study.”

I do suspect that “silent bubbles” might play a role somewhere in the body. This seems to be helped by slow ascents and deep stops.

Dr Deco :doctor:

 

[Bill51]

Hello Bill51 :

There has been a thought that “silent bubbles” in muscle tissue could be a cause of post-dive fatigue. In laboratory tests where bubbles are monitored by Doppler ultrasound, subjects do not seem to indicate fatigue associated with bubbles. That is, they do not report a problem while at the same time they do not know their bubble grade. It is a “blind study.”

I do suspect that “silent bubbles” might play a role somewhere in the body. This seems to be helped by slow ascents and deep stops.

Dr Deco :doctor:

If silent bubbles don’t play a roll in fatigue they at least have the greatest placebo effect.

I even find it amazing how much more fatigued I can get flying over 18,000’ unpressurized on 100% O2 than at 10-12,000’ without O2 under similar conditions with hydration and other factors similar.