Subclinical DCS

[JohnK]

I sometimes feel tired after a couple of dives (is it just me ?) - I put this down to being just plain knackered and not being an athlete. Someone said it could be subclinical DCS - what is this?

[John Gulliver]

Good question! I may be wrong but, as far as I can see, it seems just to be a new concept put forward to explain what you (and I, and many others) experience after a long, deepish dive or two moderately long, somewhat shallower dives and which at least I find I don't experience to the same extent when I dive on nitrox.

[MATTBIN]

Whatever it is I dont want it, but after 2 dives and a return trip to Stoney (80 odd miles each way) I'm ready for bed about 8.30, totally knackered so it looks like I've got it as well. I never said I wanted to die old.
Thats a thought, you cant get any older than dead, so surely when you die you do die old? I'm not being morbid just philosophical (typo?).
Matt

[Dr Stevil]

I think the "sub-clinical DCI" terminology is a bit of a catch-all phrase, ie if its sub-clinical how is it clinically assessed? But I feel that it is a real phenomena and I know I've felt it before, it's certainly more noticable in uk diving than warm water diving.
Chee-az
Steve

[Andy Winterburn]

Its my understanding that the reason for feeling tired after scuba diving is the fact we are breathing gas under pressure. Can't recall the medical terms used but thats it. Sorry no chamber for you Kirky, anyhow bet all the nurses are male

[PaulC]

I think that the theory goes something like this: that after most dives it is possible to detect micro bubbles in the diver's blood stream that do not give rise to acute symptoms but are abnormal nonetheless. A bend may be caused if the size of those bubbles increases to the point where they can cause identifiable damage: however the theory states that even if you do not show classic signs and symptoms of a bend there are still these abnormal micro bubbles in the blood. It is thought that a proportion of 'off-gassing' actually takes place this way with the gas circulating in the form of micro bubbles in the blood stream and not in solution.

I have come across the suggestion on more than one occasion recently that post dive fatigue is caused or contributed to by these micro bubbles. Although that isn't perhaps a bend as we know it it is a symptom of breathing compressed gas under pressure, according to that theory: perhaps that is why it has been labelled 'sub-clinical DCS'.

I wouldn't know enough about it to say one way or the other but it does seem to me (as John says) that breathing nitrox for a series of dives makes me feel less knackered afterwards.

Anyone with a deeper knowledge of this subject please post and let us know more - it must to an extent be a concern if physical symptoms are being caused by the after effects of diving, given the lack of data about the long term effects (i.e. 30+ years) of what we do!

[parahandy]

Interesting one this isn't it?
After a days or weekends diving you can be left with a variety of symptoms, feeling tired I suppose is only natural. Theres sometimes the odd ache and pain,and headache. Agree though how many of us have shook these off with the odd pain killer I have?. Enjoyed reading Paul C's slant on it. The times i've used Nitrox i've felt less tired after the dive. Theres so many dam variables in this, it only tends to become DCS if a Doctor or chambers involved. Gets you thinking though doesn't it.

[Andy Phillips]

I can't say as I have any real knowledge about this, but, just befpre Christmas I was doing some work at University College London, I just happend to pop into physiology and had a discussion with a Professor there about this, mainly it has to be said because I had been reading up on decompression theory prior to starting the TRIMIX course.

The above post about micro-bubbles in the body / blood stream is basically what it is all about. The current thinking seems to be that these bubbles are formed as you pass from deep levels to your first deco stop. It seems that they are recommending that you assend to the first deco-stop at a max rate of 3m / min with half minute stops every 3m. People have reported feeling significantly less tired after doing this than if they went straight to the first stop.

There is very little real research into this or in fact any decompression theory at the moment.

It got me thinking, and talking to said Professor, the bottom line is, it is not considered to be "sexy" science, therefore there is no money for it. Perhaps, us, that is all divers in the UK could come up with a small sum, say £5.00 a year levy for the privilage of diving in the UK. If 20,000 people paid this then It would give £100,000 which is enough to run a lab of two. The government have a matching system which would give another £100,000. Another two people plus kit.

What do you lot think, is it something we should be pushing for.

Andrew

[Phil Ennis]

Andy, I think this is what DAN research is involved in.

[JohnK]

Thanks for the info folks - indeed very interesting. I`ve always put feeling tired down to ..err.. feeling tired. Example - trip to Stoney, up at 4am, out for 5am, 3 hour drive, 2 dives to 22m (water temp 8`C) with 2 hour surface interval, 3 hour drive home. Kit up twice for dives (surely I`m not the only one that gets knackered just kitting up ??)
Get home about 4pm, sort kit, dozing off at 6pm !!!

Its a bit like the old 12 hour shifts I used to do!!

I`m not yet convinced about this subclinical DCS thing - maybe at 43 years of age and not being an athlete (err.... and yes I do smoke) I just dont lack the stamina of the young wippersnappers

Having said that some good pointers that I will be using

1.  Even Slower ascents with safety stops after every dive
2.  Nitrox

I`ll let you know if the Nitrox improves things

Thanks to all