Skin/lymph bends

ccscuba

Anyone got thoughts on if there are any special circumstances that cause lymph bends? They don't seem to be that common but do affect some people.

I dived over the weekend and got bent, firstly looked like a skin bend but then ended up with swelling on my upper left arm, and pain in the abdomen.

Dive was 83m for 20 min, 121 minute run time used a vpm vr3 plus some additional stops to clear Boris.

I was not tired, well hydrated, been taking my antioxidants, not working hard under water.

an hour on o2 cleared the skin mottling but the upper arm swelling took 4 days to go, and it's still a bit sore now.

Any ideas?

m

JonnyB

That is very strange... what setpoint did you run? I did a test on this and i was cleared at 96 minutes and that is on a vpm +2 conservatism....
Did you run on a 1.0 setpoint?

/Jonny

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bendomatic

I can't answer your questions definitively, i can only give my experience.

My experience was on OC trimix (60m/20 min,) and it was the crusiest dive i had done in ages, no problems with the dive execution or physical stress (except when i got out of the water). Shortly after getting out of the water i had a burning sensation on my abdominal skin emanating from my diaphragm. it felt like a cold burn from dry ice. this progressed to coughing and shallower breahting. By the time i got back to shore i had mottling around my abdomen and back, a red raised rash from upper thighs to breasts, and boy did i hurt. i knew i should have had treatment but drove for an hour back home breathing 50%02 (dumb dumb dumb! ). 45 min of the O2 settled the mottling and breahting problems, but i was left with all the lymph nodes of my abdomen swollen, it felt like bubble wrap. Slept for 13 hours. couldn't do anything more vigourous than a walk because of the pain from the swelling the next day. It took 5 days for the swelling to go away.

I was silly (at best) not to go get treatment at a chamber. However as this wasn't the first time for me, i decided on a more thorough investigation. After many consultations with doctors, after being told that i was going to kill myself if i keep diving (Chamber director), after being told that what i was going to do was akin to cosmetic surgery (first cardiologist and chamber director), I have since had a PFO closure procedure and have continued diving. Its now been 360 days since i had this done, i've done dives down to 50ish m, deco, trimix and now learning on CCR etc, without problems.

But to emphasise: Time will tell! i couldn't say definitely if the PFO contributed to my previous bends experiences, i just know its not going to be a contributor to any future experiences.

best wishes with your diving
rachel

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Loneshark

My only experience of this was with a customer last year. He was diving a YBOD and had a modest amount of deco (compared to the OC guys) after 25mins at 50m. He had symptoms within an hour of surfacing and was evacuated to a chamber the next day (as we were in a remote location). I couldn't understand how/why he had got bent. Following up with the hospital, it became apparant the guy had cancer 4 years earlier, and was in remission. Unfortunately it transpired he had secondaries in his lymphatic system (which he didn't know about).
I don't think for a moment that is the problem affecting you, but I just mention it as annecdotal evidence of "lymph bends".
I suppose the best advice is "if you are concerned, go get professional advice".

AD_ward9

Perhaps a new treatment? Cancers tend to have poor blood flow (hence cancer drugs are hard to get to the right tissue), and if that is the case they will be damaged by the bends faster than other tissue. Perhaps a treatment is to test what is the half life of the cancer cells, using biopsy material, then work out a profile that stresses that compartment more than others. Interesting thoughts ...

Anyhow, back to topic: whether you get a skin bend or a lymph pain, or joint pain is dependent on four things:
1. The half life of the tissue compartment.
2. The amount of tissue in that compartment.
3. How much you bend the compartment.
4. What tissue loading the particular dive profile has produced in each compartment.

These factors determine the stress you cause to the cells in each tissue compartment and the effect on other organs (i.e. the quantity and size of the bubbles in your blood that the compartment is causing).

Dozens of other factors change the compartment half lives, from alchohol in the blood to the timing of hard exercise - whether 12 hours before the dive () to 4 days before the dive () to just after the dive (). The sheer number of parameters that drive any particular DCI event makes general statements risky.

Skin has a very short compartment half life. This means skin bend more easily than other tissue because it loads up with gas faster than other tissue, and tries to unload the gas faster also.

I do not know what the value is for lymph tissue. Anecdotal evidence is that it is also very short.

Just because one sees a skin bend does not mean that other compartments are not overloaded also, like the nerve tissue in your spine, which also seems to have a short half life.

Finally, many divers ignore evidence that diving with the wrong gas in your suit can cause serious skin bends! Skin is fairly porous. There are quite a few papers I have read about using N2 in the suit when diving helium mixes, and vica versa, that show this is a bad idea. After I read those papers, I decided to always use the same mix in my suit as I breathe. The cooling effect of helium is not a big deal shallow (and I only dive cold water). At real depth, the cooling effect of helium is an issue but for tech dives people do not spend enough time really deep to make the risk of using the wrong gas in the suit one that is worth taking.

Alex

NB 1:
I know, medics have 20 different names for a skin bend. As divers we mean skin bends vary from red mottling, to a severe burning sensation as if scalding water was poured over the skin, to bubbles of gas under the skin surface.
NB 2: I am not a medic, but then neither are/were most involved in decompression research. I am reasonably informed on the maths of various deco algorithms, and well read up on the history and research papers for deco algorithms.

ccscuba

Set point 1.2, run time about same as vpm b/e conservatism +3.

Any other experiences of cancer and bends?


m

Andy Del

This just goes to show how different people are as far as tolerances go. I did just one dive using trimix to inflate my suit (during my TX course ). It was to 78m and the water was around 17C. Last 30 minutes of deco I was shivering uncontrollably and felt extremely cold (not surprising really). Using something other than helium (travel gas, or these days my nitrox bailout) doesn't see me feeling cold in this manner anymore.

My question is, if using N2 (or a similar gas, such as O2[?]) in the suit and helium as a breathing gas, or vice versa is a bad idea, then should one and how should one, take this into consideration as the gas we breathe changes as we ascend?

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AD_ward9

You are right in that variance is a big issue: I spoke purely from personal experience and forgot that I am probably not average in this particular instance - I dive without a hood when the water is more than 52F, and feel quite comfortable most others on the boat use a hood and still feel cold. For me, I did not see any difference with helium, and do not shiver or feel cold with it, but accept your point: other people may need a different solution. I do not think that solution is a different gas in the suit through.

If you feel cold with He in the suit, you could use a heated jacket like the Typhoon Icebreaker or the EXO2 jacket to keep warm. Doing that is better than mixing gas in the suit just for warmth.

The underlying issue behind my decision is the evidence of bends when using a different mix in the suit to that one is breathing: some interesting papers on this, for anyone wanting to look.

Cheers

Alex

Scuba_Vixen

Any issues about whether helium in your inflation gas makes you colder or not aside;

I understood the concept of not using helium, especially high fractions of it, in your suit gas, revolved around it's ability to perfuse the skin. The longer/deeper you are, the more helium loading to your system, and none of it is being accounted for by your deco planning.

Using a heavier gas with much less perfusion potential, in theory, puts the skin and tissue served by that immediate circulatory network at much less risk.

A very conservative deco might mitigate the additional helium loading, where a more aggressive one may not be able to.



Darlene

AD_ward9

That is not what the researchers who tested this found to be the case.

Nitrogen does perfuse into the skin. It perfuses out much less slowly than helium, and on the profiles they tested, they could increase DCS incidence by using heliox for the diver and nitrogen mixes for the suit.

Cheers

Alex