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RenaB wrote:I was solely basing my statements off what I know to be solubility principles, and what I have personally observed from samples in the lab I work in. If nitrogen is being dissolved into the liquid portion of your blood and you have less of it, due to dehydration, it's coming out of solution quicker than somewhere with more as they surface. That is a chemical fact, if the statement is true that it's dissolved in your blood then the latter is true.
As for the dehydration of caffeine, I stated that it is a recommendation to drink water. I guess it would depend on how much water is in your coffee. I know it dehydrates me.
As for whether other factors play a role, I am sure they did. I would argue that this was a large factor.
Sounds good to me - drink up!
More Pics Than You Have Time To Look AT "Anyone who thinks this place is over moderated is bat-crazy anarchist." -Ben, Airsix "Warning: No dive masters are going to be there, Just a bunch of old fat guys taking pictures of fish." -Bassman
And although I didn't do any research at all when making the above statement (as noted in my next post), here is a study that provides VERY good proof that dehydration plays a large role in DCS, in an experiment put on by the Aerospace Medical Association. The abstract to that paper follows: (public record)
Background: Several physiological factors have been suspected of affecting the risk of decompression sickness (DCS), but few have been thoroughly studied during controlled conditions. Dehydration is a potential factor that could increase the risk of DCS. It has been suggested that hydration may enhance inert gas removal or increase surface tension of the blood. Hypothesis: Dehydration increases DCS risk. Methods: Littermate pairs of male Yorkshire swine (n = 57, mean ± 1 SD 20.6 ± 1.7 kg) were randomized into two groups. The hydrated group received no medication and was allowed ad lib access to water during a simulated saturation dive. The dehydrated group received intravenous 2 mg · kg−1 Lasix (a diuretic medication) without access to water throughout the dive. Animals were then compressed on air to 110 ft of seawater (fsw, 4.33 ATA) for 22 h and brought directly to the surface at a rate of 30 fsw · min−1 (0.91 ATA · min−1). Outcomes of death and non-fatal central nervous system (CNS) or cardiopulmonary DCS were recorded. Results: In the hydrated group (n = 31): DCS = 10, cardiopulmonary DCS = 9, CNS DCS = 2, Death = 4. In the dehydrated group (n = 26): DCS = 19, cardiopulmonary DCS = 19, CNS DCS = 6, Death = 9. Dehydration significantly increased the overall risk of severe DCS and death. Specifically, it increased the risk of cardiopulmonary DCS, and showed a trend toward increased CNS DCS. In addition, dehydrated subjects manifested cardiopulmonary DCS sooner and showed a trend toward more rapid death (p < 0.1). Conclusion: Hydration status at the time of decompression significantly influences the incidence and time to onset of DCS in this model.
Rena
Drink water, breathe air. Never get these mixed up.
RenaB wrote:And although I didn't do any research at all when making the above statement (as noted in my next post), here is a study that provides VERY good proof that dehydration plays a large role in DCS, in an experiment put on by the Aerospace Medical Association. The abstract to that paper follows: (public record)
Background: Several physiological factors have been suspected of affecting the risk of decompression sickness (DCS), but few have been thoroughly studied during controlled conditions. Dehydration is a potential factor that could increase the risk of DCS. It has been suggested that hydration may enhance inert gas removal or increase surface tension of the blood. Hypothesis: Dehydration increases DCS risk. Methods: Littermate pairs of male Yorkshire swine (n = 57, mean ± 1 SD 20.6 ± 1.7 kg) were randomized into two groups. The hydrated group received no medication and was allowed ad lib access to water during a simulated saturation dive. The dehydrated group received intravenous 2 mg · kg−1 Lasix (a diuretic medication) without access to water throughout the dive. Animals were then compressed on air to 110 ft of seawater (fsw, 4.33 ATA) for 22 h and brought directly to the surface at a rate of 30 fsw · min−1 (0.91 ATA · min−1). Outcomes of death and non-fatal central nervous system (CNS) or cardiopulmonary DCS were recorded. Results: In the hydrated group (n = 31): DCS = 10, cardiopulmonary DCS = 9, CNS DCS = 2, Death = 4. In the dehydrated group (n = 26): DCS = 19, cardiopulmonary DCS = 19, CNS DCS = 6, Death = 9. Dehydration significantly increased the overall risk of severe DCS and death. Specifically, it increased the risk of cardiopulmonary DCS, and showed a trend toward increased CNS DCS. In addition, dehydrated subjects manifested cardiopulmonary DCS sooner and showed a trend toward more rapid death (p < 0.1). Conclusion: Hydration status at the time of decompression significantly influences the incidence and time to onset of DCS in this model.
Yep- it's pretty well accepted in the community of divers that do decompression dives that hydration is important. But for those of us that actually DO decompression dives (and, yes, I do know that every dive is a decompression dive- but if you were going to pounce on that, you already know what I'm talking about) we know that hydration is just one of many factors that play in to a decompression, and doesn't adequately explain divers that do everything "right," including adequate hydration, and still get bent. There IS no magic formula that will work for every diver, every time.
