Aging, DCS, and Deeper Diving

[bsumner]

Sure are, JR:

1. Perform deep stops when appropriate (e.g., "Rules for the NAUI Recreational RGBM Tables (Air, EANx32, and EANx36); 1. make a 1-minute safety stop at half the depth between bottom and surface for depths in excess of 40 fsw (12 meters); 2. make a 2-minute safety stop in the 15 fsw (5 meter) zone after the deeper safety stop; 3. make a 3-minute safety stop in the 15 fsw (5 meter) zone
for all bottom depths shallower than 40 fsw (12 meters)").

Helpful post!

Since I am mid-fifties, I do a two minute safety stop at half the depth below 40 ft. and still do my full three minutes at 15 ft. Probably overkill, but I like to err on the side of safety.

 

[bsumner]

I'm 62 and try to go below 100 ft. Ever. I think you were really pushing the limits going that deep and doing that many dives. I diveEAN and don't find it that much better. Besides I really don't see much better sealife at that depth anyway. As I age I personally see the effects that deep dives have on my body. I just finished my Master Diver Certification and continue to take classes to keep in touch with trends/safety issues. Deep dives are not part of my agenda

I agree that he was pushing the limits.

In my own experience, I find that I am less fatigued when diving 30+ EAN than straight 21%, so it helps me on that front as well.

 

[diverdoug1]

OK, quick paradigm shift from neo Haldanian; if you don't exceed critical supper saturation , you don't get bubbles, if you don't get bubbles you don't get bent..... to..... dual phase; if you don't exceed critical gas volume in the free phase, you don't get bent because the bubbles you do get are sub clinical. Yes I know, very simplistic, but I want to keep it short.

I have no problem with the fact that very slow ascent rates will show less sub clinical bubbles than one done at the algorithms standard ascent rate. I'd say it's not only intuitive, but there have already been studies that show this to be the case. Non the less, the off gassing at these slow rates is not as effective & the extra time spent at depth means that some tissues aren't off gassing at all, but rather on gassing during the ascent.

So you come out of the water with less bubbles. But do you come out of the water with lower or higher tissue saturation?

The bubbles most of us exit the water with using a 10mt/min ascent rate & for many in the past even double that, are sub clinical (not even fatigue). I don't quite see the point of supper slow ascents that may lead to leaving the water with a higher level of tissue saturation.

Possibly when your research is published I'll have some more to think about. Until then & just for interest....
is there a working title for your paper?
Not at this time
is the number of bubbles/ascent rate you've mentioned a sub set of a more holistic study?
Yes, it also includes diver core temperature
could you give a concise H_o for the test you mentioned.
what was your sample size
curently 14 test divers, each with between 20 and 41 tested dives[/I]
your p value was less than 5%, what was the exact p value?
As I said, our p is greater thn 5%, because we have not collected enough dives yet
how many categories were you using, (what was the df)?
5 ascent rate classes, 14 test divers,depth, Standardized bottom time for each depth core temp analysis will be retrospective
how did you arrive at the expected bubble count v's the observed result?
Base line measurement for each depth, for each diver @ accepted max. ascent rates
how were you counting the bubbles?

Precordial and carotid ultrasonography

 

[DCBC]

From what I understand there is no conclusive finding about aging and DCS as long as the aging diver is in good physical condition. Maybe I am wrong about that.

Anything else I can do to address any potential relationship between DCS and aging?

Thanks
JR

There are some reports that indicate a higher risk of DCS with increasing age, but as you've already mentioned fitness seems to be more important. Some other factors are previous bone injury and/or previous incident of DCS.

There's been quite a bit of discussion on the Board lately on topics including: in-water decompression treatment for DCS as well as diving tables & computers, which you may find helpful to read.

To put your mind at ease and to put things into perspective, I recently passed an insurance company hyperbaric medical for saturation diving (as the Diving Director I probably won't get wet, but it was required). I'm 56 and have had one previous case of Type I DCS. So age alone isn't usually a barrier.

It's good practice to talk about your health and previous injuries with a hyperbaric physician, if you have any concerns before you dive. If you adhere to a liberal decompression profile, you should be fine. Nitox is arguably a lower gear, so that may be a better route if the depth restrictions are acceptable.