Decompression Illness - varying susceptibility

[60plus]

Just been having a read of the recently published 2019 BSAC diving incident reports and in the decompression illness section there are many cases of DCI occurring during dives and circumstances that I and many others have exceeded frequently without DCI. A probable contributory factor of this randomness of DCI is individual physiology but it is unlikely that is the sole factor. During training my instructor who has done many thousands of dives and has had DCI himself told me that even adhering to my computer and diving within recommended guidelines (safety stops etc) the risk of DCI was still about 1 %.

Any thoughts?

 

[Akimbo]

There are lots of variables but circulatory problems and joint injuries are common culprits.

 

[Gareth J]

Have a look at this thread, a lot of this was discussed here.

Kudos for reading the BSAC incident report, you can learn a lot for the incident report. It will have an effect on your diving.

 

[GJC]

Changes in blood circulation can affect gas diffusion in and out of tissues.

If you start a dive warm, well hydrated and work hard during the dive, you have good circulation and it's easy for nitrogen to get into your cells.

At the end of the dive, if you get cold, dehydrated and are not moving at all at your safety stop, you can have poor blood circulation to some of your cells and nitrogen does not diffuse out of the cells very well.

 

[Johnoly]

Not just DCI.....Every person's body adjusts differently.

I have a couple of friends that dive 3 digits deep almost 7 days a week at times. That little O2 meter that stays stuck in the Red for them on hot mixes daily has never resulted in an Ox-Tox.

Everyone's different....Your dive computer is just an algorithm, not an absolute line of death.

 

[boulderjohn]

Pretty much everything I have read recently points to personal differences as being critical.

 

[JonG1]

This is quite interesting and kind of related:

The Unearned Bullhit

I guess we are lucky now that GFs give us an option to tweak deco models to fit experiential feedback but even then individual susceptibility will play a part and change daily.

I moved my GFs after a hit and have been fine since, but constantly monitor and flex the deco pre and during a dive if I think I need to.

 

[100days-a-year]

Wrong by a quite a bit. Significantly lower that .1% much less 1%.

 

[dmaziuk]

Any thoughts?

Download the 1994 DSAT report from the Rubicon Foundation and read the introductory chapters. In particular "3. Decompression testing and statistics", "6. Safe or reliable; DCS is not an accident", and the bit on validation of USN air tables.

We had a DM once who said when she got into the chamber and the staff asked how many dives she had under her belt, upon hearing the answer the doc said "don't waste any time trying to figure out whats and hows: with this many dives, it's just your time".