A pre-dive meal at KFC or MickeyD's to reduce risk of DCS?+

[JanK]

Dan Volker's reputation is known on this board. On what are you basing your statements? A Snopes' decry of a single myth, and an opinion from the 3-year-old DAN proceedings?

Did you actually read anything of the texts to which I provided the links (or indeed the whole post as opposed to parts of it)?

If you did, I cannot see how you have failed to notice that in addition to Snopes I also provided links to two articles, one published in the American Journal of Physiology, the other in the Journal of the American Society of Nephrology, both written by university researchers.

As for the opinion from the 3-year-old (if I understand you correctly, this somehow makes it worth less - why?) DAN proceedings, if it's an opinion by Simon Mitchell, Richard Pyle (does the phrase "pyle stops" ring a bell) and Richard Moon I tend to place a lot of weight on it. If you have a reason not to do so, I'd like to hear it, please.

 

[Jax]

Yes, I did.

Did you read post #6? and post #9?

 

[Thalassamania]

Did you actually read anything of the texts to which I provided the links (or indeed the whole post as opposed to parts of it)?

If you did, I cannot see how you have failed to notice that in addition to Snopes I also provided links to two articles, one published in the American Journal of Physiology, the other in the Journal of the American Society of Nephrology, both written by university researchers.

As for the opinion from the 3-year-old (if I understand you correctly, this somehow makes it worth less - why?) DAN proceedings, if it's an opinion by Simon Mitchell, Richard Pyle (does the phrase "pyle stops" ring a bell) and Richard Moon I tend to place a lot of weight on it. If you have a reason not to do so, I'd like to hear it, please.

Anecdotal data is not worth much, but ... in the late 1960s I picked up the habit from some French divers whom I resepected to drink a liter of liquid (usually OJ) and take a baby aspirin before every dive. I have done this now for over 15,000 dives and I have never had any kind of DCS, but then I am also very careful about depth and time and ascent rate. I intend to keep on doing so, though I have no reason to recommend that you do so. When I was diving with Pyle he did not do so, but he also did not comment on my "habit." As far as fatty meals are concerned, puking a Big Mac through my regulator when I was young and foolish was an experience that has keep me out of McDonalds ever since.

 

[Insta-Gator]

 

[JB]

I'm afraid hyperhydration with water can be deleterious to your health! Had a lady the other day told to drink "a lot" of water for an ultrasound, as her bladder wasn't full, and she arrived fitting from low blood sodium content. (I guess her interpretation of "a lot" was not the same as mine might have been). Like almost everything, the truth is always somewhere in the middle, and everything in moderation is fine/good. Depends what you want, if you are rehydrating low blood volume you need close to isotonic fluid (0.9% NaCl), if you are replacing sweat from exercise you need a very hypotonic fluid as sweat is 0.2% NaCl. "Guru's" seem to run on faith, hero-worship, anecdotal tales and not science, their major gift seems to be the ability to make others believe, (and part with excessive amounts of money). You can't argue with the faithful, because it is not based on logic, evidence, common sense or science.
I think the 8 glasses of water thing refers to total fluid intake rather than just H2O, so if you had close to 2 litres of total fluid intake daily that might be the norm. I would contend that the human body is pretty bloody marvelous at maintaining homeostasis, and can cope with most things that you might throw at it. Without massive excesses it will maintain normal hydration, and electrolytes. You have to really overwhelm it's capacity to get into trouble. I suspect for someone to be dehydrated there has to be a cause (eg. alcohol), and I wonder if the DCS refers to those that are pathologically dehydrated and not to some one in perfect health with normal fluid balance? You can only transiently hyperhydrate, because the body will sort itself out very quickly, and get rid of the excess fluid.
I think this is one for "Mythbusters".

 

[Insta-Gator]

Compromise: Water during the day, beer at night.

 

[Jax]

I suspect for someone to be dehydrated there has to be a cause (eg. alcohol), and I wonder if the DCS refers to those that are pathologically dehydrated and not to some one in perfect health with normal fluid balance? . . .
I think this is one for "Mythbusters".

Really??? Seems like you nailed this one on the head! (At least in my experience in travel to vacation places and looking at the other divers who spent the previous night up late drinking and puking . . . )

 

[danvolker]

I'm afraid hyperhydration with water can be deleterious to your health! Had a lady the other day told to drink "a lot" of water for an ultrasound, as her bladder wasn't full, and she arrived fitting from low blood sodium content. (I guess her interpretation of "a lot" was not the same as mine might have been). Like almost everything, the truth is always somewhere in the middle, and everything in moderation is fine/good. Depends what you want, if you are rehydrating low blood volume you need close to isotonic fluid (0.9% NaCl), if you are replacing sweat from exercise you need a very hypotonic fluid as sweat is 0.2% NaCl. "Guru's" seem to run on faith, hero-worship, anecdotal tales and not science, their major gift seems to be the ability to make others believe, (and part with excessive amounts of money). You can't argue with the faithful, because it is not based on logic, evidence, common sense or science.
I think the 8 glasses of water thing refers to total fluid intake rather than just H2O, so if you had close to 2 litres of total fluid intake daily that might be the norm. I would contend that the human body is pretty bloody marvelous at maintaining homeostasis, and can cope with most things that you might throw at it. Without massive excesses it will maintain normal hydration, and electrolytes. You have to really overwhelm it's capacity to get into trouble. I suspect for someone to be dehydrated there has to be a cause (eg. alcohol), and I wonder if the DCS refers to those that are pathologically dehydrated and not to some one in perfect health with normal fluid balance? You can only transiently hyperhydrate, because the body will sort itself out very quickly, and get rid of the excess fluid.
I think this is one for "Mythbusters".

Let's go at this from a cyclist's perspective....If I ride 40 miles per day, 4 to 5 days per week, I am losing about 1.5 quarts of fluid by sweating each ride...av pace 21 to 25 on my own, with no pace line, in florida heat.

I have to drink more than this though. because more is going on than just replacing what I lost for body cooling.
I am probably burning 2500 to 3000 calories at minimum on the ride, and my metabolism is cranked up for the day....Water is an essential part of the chemical side of the digestive process, and the more metabolic demand, the more food and the more water is being called for....lately, I have been eating less and letting stored food handle some of the metabolic load

When people say you need only 8 glasses a day, first, I will say they don't live in florida, next, they are not training at any kind of aerobic level, and third, they dont get what can happen when you get your body used to a gallon or more of water each day----this actually changes your metabolism

 

[danvolker]

From a diver's need perspective...
My thoughts on this, are that a diver that wants to push the envelope ( their own personal envelope, and or the envelope for all of us) needs to increase their cardivascular development...better perfusion, less effort on dives due to conditioning, lower breathing rate due to less effort swimming -- by training adaptations. This diver will be training many days per week, and training hard. They will eat high protein, low sugar diets. They will need to drink far more than 8 glasses of water per day, because:

1. their system is used to drinking more like a gallon of water every day, and you tend to need this amount of water once your system adapts to it ( after 2 to 3 weeks, everyone I ever knew that tried Terry's 2 gallon per day optimaization, got radical benefits in recovery from workouts, fat loss, and general energy levels, as well as better glycogen levels in muscles. This is at least 40 to 50 people i personally have known to try this, which can be added to the thousands or tens of thousands Terry ran through the gyms as his personal lab rats--all getting tremendous benefits.)
2. A fit diver here in Florida, will sweat out at huge amounts of water, in their body's attempt to stay cool...an athlete can perspire and cool better than a sedentary person, but will also have a much higher metabolic rate, meaning their body will run hotter, and need more cooling The opposite is a 95 year old Century Villager, wearing a sweater on a 90 degree day.
3. Gas exchange is better when well hydrated....I'm sorry, this is just to easy to prove for each person, themself, it they try cycling dehydrated, versus well hydrated. If the gas exchange is so much better on the bike, why should it not factor in on a dive?
   1. Some of us, like George Irvine and myself, have always offgassed much faster than the tables would predict we should, as was shown by many dopplers that were done in the late 90's. We both were training in cardio sports at elite levels, and both were drinking more than a gallon of water every day. For a diver, this would appear to be relevant, though clearly it does not prove anything all by itself. But remember, "good science is good observation"

 

[DocVikingo]

... in the late 1960s I picked up the habit from some French divers whom I respected to drink a liter of liquid (usually OJ) and take a baby aspirin before every dive.

Hi Thalassamania,

And the reason for this is?

There really is no research or diving medicine expert support for doing so.

E.g.:

Research:

“J Appl Physiol. 2011 Jan 6.

Pharmacological intervention against bubble-induced platelet aggregation in a rat model of decompression sickness.

Pontier JM, Vallée N, Ignatescu M, Bourdon L.

1 Naval Medical Institute.

Abstract

Decompression sickness (DCS) with alterations in coagulation system and formation of platelet thrombi occurs when a subject is subjected to a reduction in environmental pressure. Blood platelet consumption after decompression is clearly linked to bubble formation in humans and offers an index for evaluating DCS severity in animal models. Previous studies highlighted a predominant involvement of platelet activation and thrombin generation in bubble-induced platelet aggregation. In order to study the mechanism of the bubble-induced platelet aggregation in DCS, we examined the effect of acetylsalicylic acid (ASA), heparin (Hep) and clopidogrel (Clo), with anti-thrombotic dose pre-treatment in a rat model of decompression sickness. Male Sprague-Dawley rats were first compressed to 1000 kPa for 45 min then decompressed to surface in 38 min. In a control experiment, rats were treated with ASA, Clo, or Hep, and maintained at atmospheric pressure for an equivalent period of time. Onset of DCS symptoms and death were recorded during a 60-min observation period after surfacing. DCS evaluation included pulmonary and neurological signs. Blood samples for platelet count (PC) were taken before hyperbaric exposure and after surfacing. Clopidogrel reduces the DCS mortality risk and DCS severity. Clopidogrel reduced fall in platelet count and bubble-induced platelet aggregation (-4,5% with Clo, - 19.5% with ASA, -19,9% with Hep and -29,6% in the untreated group). ASA which inhibits the thromboxane A2 pathway and Hep which inhibits thrombin generation have no protective effect on DCS incidence. Clopidogrel, a specific ADP-receptor antagonist, reduces post-decompression platelet consumption. These results point to the predominant involvement of the ADP release in bubble-induced platelet aggregation but cannot differentiate definitively between bubble-induced vessel wall injury and bubble-blood component interactions in DCS.”

Expert opinion:

- Dive Training, September 2008 Volume 18 Number 9, statement by Joel Dovenbarger, recently retired Vice President for Medical Services at DAN: "There is no benefit to taking aspirin before a dive any way you look at it. Aspirin will no more prevent DCS than it will prevent pain if you fall down while taking it. There is no anti-bubble-formula aspirin or nitrogen off-gassing dosage that will make any difference, at least none that has ever been reported. In studies, there was no change in outcome for people who took aspirin versus those who did not, and researchers have pretty much stopped looking at aspirin in DCS. So, no matter what you do, the outcome is pretty much the same. By the way, the same is true for oral steroids. Even after you have symptoms, there is no outcome change with or without steroids and it will not prevent DCS. There is also at least one circumstance where aspirin could be problematic, and that's if someone takes so much aspirin that it causes hearing issues or impedes blood clotting. Aspirin is toxic to the eight cranial nerve in high doses, and may prolong bleeding, which is something you don't want to have happen if you've ruptured a small vessel in the spinal cord or brain from AGE [arterial gas embolism] or DCS."

- See post #31 (by a noted diving medicine cardiologist) in the following thread --> http://www.scubaboard.com/forums/diving-medicine/256344-aspirin-diving-4.html

The above notwithstanding, taking a baby aspirin before every dive in an effort solely to prevent DCS under such circumstances as a liveaboard where 4 or more dives day are being done over 7-10 days, a not uncommon situation, is taking too much ASA.

Regards,

DocVikingo