Does Dehydration / Fatigue lead to DCS?

trimix

Do any of our resident Professionals know of any articles or studies that relate how much of a factor dehydration plays in DCS? And what about fatigue?

• How dehydrated does one have to be, to have increased risk of DCS? Just thirsty?
• Is there a way to know if you are 'dehydrated' to a problematic degree?
• How do you rehydrate yourself effectively if you are frequently 'dehydrated'? (cheeky monkeys: don't say 'drink more'!)

And about fatigue: obviously there are different levels - from needing a nap, to barely able to get into the water... But for most of us, would there be an increased risk of DCS if we were diving after a difficult physical workday, or a mentally demanding week at the office?

Comments?

__________________
Just another piece of Mel's Train Wreck !
BOOM!

ScubaDadMiami

There was just a Rubicon reference about pre-dive hydration. Run a search for that. Probably a good start.

__________________
Howard Packer
IANTD CCR Instructor
Miami Beach, Florida
CCRDiveTraining.com

Gene_Hobbs

Thanks! Here is the paper that just came out:

Gempp E, Blatteau JE, Pontier JM, Balestra C, Louge P. Preventive Effect Of Pre-Dive Hydration On Bubble Formation In Divers. Br J Sports Med. 2008 Mar 4; [Epub ahead of print] PubMed ID: 18308884 the abstract the published for the last EUBS Meeting gives more detail than the pubmed version. (EUBS listed under Newsletters/ EJUHM on left, file is Volume 8 Number 3.)

Here are a few select references from that paper:

9 Skogland S, Hope A, Sundland H, et al. Effect of water deprivation and decompression on venous gas emboli in conscious rats. Proceedings of the XXXIInd Annual Meeting of the European Underwater and Baromedical Society; 23-26 Aug 2006;Bergen, Norway;2006:29-31. (NOTE: Volume 6 link above)

10 Broome JR, Kittel CL, Dick EJ. Failure of pre-dive hydration status to influence neurological DCI rate in pigs. Undersea Hyperb Med 1995;22(suppl):52. (NOTE: will be added to the RRR when we have a chance to get to 1995)

11 Fahlman A, Dromski DM. Dehydration effects on the risk of severe decompression sickness in a swine model. Aviat Space Environ Med 2006;77:102-6. (NOTE: ASEM is online here but not all content is free)

12 Leni P, Menu JP, Laforest F, et al. Extracellular dehydration induces functional motor spinal deficit after severe decompression in the rabbit. Proceedings of the XXVIIth Annual Meeting of the European Underwater and Baromedical Society; 12-16 Sep 2001;Hamburg, Germany;2001:13-17. (NOTE: Volume 2 linked above)

13 Plafki C, Almeling M, Welslau W. Dehydration-a risk for decompression accident in diving. Dtsch Z Sportmed 1997;48:242-4.

15 Regnard J, Roy C, Peyras C, et al. Dehydration is common after sport diving. Proceedings of the XIVth Annual Meeting of the European Underwater and Baromedical Society; 5-9 Sep 1988;Aberdeen, Scotland,UK;1988:47-9.

17 Hjelde A, Koteng S, Eftedal O, et al. Surface tension and bubble formation after decompression in the pig. Appl Cardiopulm Pathophysiol 2000;9: 47-52.

18 Walder DN. Serum surface tension and its relation to the decompression sickness of aviators. J Physiol Lond. 1948;107:43-44 (NOTE: This is the supplement and it is an abstract. Full work of this study is Walder. 1945. The Surface Tension of the Blood Serum in "Bends". Royal Air Force Technical Report)

35 Hjelde A, Brubakk AO. Variability in serum surface tension in man. Appl Cardiopulm Pathophysiol 2000;9: 9-12.

Also of interest would be:

Conkin J. A literature survey: fluid balance in animals and man and its influence on decompression sickness. Houston, TX: Technology Incorporated; 1983:1-27. (NOTE: will be added to the RRR when we have a chance to get to it)

I have a friend translating this one for me but we do not have permission to add it to the RRR:
K-P Munchen. 1971. [Decompression Experiments with Animals as a Function of the Water Balance of the Organism] Deutsche Luft- und Raumfahrt. Forschungsbericht 71-20.

Hope this helps get you started... as for fatigue... well, I'd have to find a good starting point and have not personally looked into it. The tools for searching are getting better. Have fun!

__________________
http://rubicon-foundation.org/
Home of the Rubicon Research Repository.
For help getting started with the Repository, please visit our FAQ page. PLEASE support our work.

"Oxygen is addictive and deadly. Everyone who uses it will eventually die" --RW Hamilton, PhD 1991

jkaterenchuk

With regards to how can you tell if your dehydrated...here are a couple of things. I am passing them on for information as they are not mine and I do not claim they are accurate:

If your not drinking a minimum of 12 x 8oz glasses of water per day then you are probably dehydrateds....if you exercise you need to drink more. This is alot of water....try to do it sometime and you will see.

Might be a old wives tale but I remember being told that if your urine is yellow then you are on the dehydrated side of the table....the more yellow the more you are dehydrated.

John

nigelh

If those are US fl. oz. then that's 2.8 Litres.

After a run in with Kidney stones the Urology department at the local hospital told me to drink 3 litres a day at least.
"What? Because I had the stones?"
"No. Everybody should drink at least that much."

Once I sat down and thought about how little I drank against that as a yard stick I can quite see why the plumbing silted up and caused all that pain.

__________________
nigelh

andrespp

Just finished a safety diving course. IAW training gurus, dehydration is the main factor that leads to DCS. It is deemed to be more significant than age, obesity, etc.

It is important to drink water enough, but most important is to drink frequently.

Fatigue also contributes to DCS, but all I have been told is that a diver should be rested before going into water.

shil

Years ago my yoga instructor insisted we drink at least 12 glasses of water a day, as laid down by the first yoga manuals and practitioners.
To make it easier for beginners he asked us to make it a habit of drinking fixed amounts at regular intervals and also avoiding too many glasses before and after meals. So it broke down to- 3 glasses first thing in the morning , 3 glasses mid morning. 3 mid afternoon, 3 at bed time. any more as required by lifestyle, so totalling more than 12 glasses.
Difficult at first but soon, it become a habit and then second nature.

Shil

Simon Mitchell

With all due respect to your training gurus, this is not proven by any stretch of the imagination. Indeed, prior to the recent study in Br J Sports Med, there were no studies of direct relevance in humans and the animal studies were conflicting. Moreover, the recent study in humans demonstrated an increase in venous bubble formation in less well hydrated divers; not an increase in risk of DCS. The correlation between venous bubble grade and DCS risk is not as good as you might think based on first principles. Some of the other citations provided by Gene are only indirectly relevant, and are from non peer reviewed publications whose value is uncertain.

All we can say at the present time is that the weight of evidence favours the hypothesis that dehydration is a risk factor for DCS. It certainly does not justify a claim that dehydration is the pre-eminent cause.

Warm regards,

Simon M

andrespp

I was saying just what I was told in the training sessions; meanwhile I do not know what scientific support they rely upon, what I can tell is that the instructors were highly qualified, most of them with more than 30+ years of technical diving experience.On a side note, I am engaged right now on the ANDI manual, and it also points dehydration as one of the main factors that leads to DCS. Does not say it is the pre-eminent one, however....

Captain Nemo

__________________
Look beyond the dark side into the light.




Beware of false knowledge; It is more dangerous than ignorance.