The Iceni
Medical Moderator
Hi Dr Deco,
Here I am for the second time after my winter hybernation.
Like Ralph, I am somewhat amused by all the theories about why we should not drink carbonated or other specified beverages during a diving trip.
Like so many recommendations I suspect in the dim and distant past there were very good reasons to suggest that these were not so good for you when diving. Perhaps this harks back to the days when cokes contained the actual stimulant after which they are named!
If I can bring this discussion down to earth with a bump may I say that the fit human body is pretty good at maintaining itself in physiological balance (homeostasis). I believe this discussion is about the choice of beverage during a dive trip in order to maintain hydration because dehydration predisposes to DCI.
It should not about the treatment or prevention of dehydration in the clinical sense, which is where products like paedialyte (dioralyte/rehydrat in the UK) and gatorate are indicated. The former are designed to prevent dehydration and salt loss in pyrexial infants and children with diarrhoea and vomiting and, if gatrorate is what I think it is, it is to prevent "stokers cramps" by replacing the salts (and fluids) lost by excessive perspiration in a hot environment, such as a ship's boiler room or tropical rain forest.
Submersion itself directly causes a considerable diuresis and the gas used in open circuit scuba is dry. Thus without an above-average fluid intake during a dive trip the diver will become relatively dehydrated, but by itself this is not a danger.
Mixing this with unconservative dive profiles or a DCI hit is another matter.
Unless you drink a good qauntity of hypertonic solution such as sea water or ingest a powerful diuretic I believe I am right in suggesting that all the usual beverages will be beneficial and rehydrate you, some better than others and some more pleasantly than others!
Caffeine causes a diuresis and is a stimulant so is not really recommended but boy doesn't a hot cup of tea or coffee make you feel so much better after a cold dip in the North Sea! I'll happily take my chances with that one but there is far too much caffeine in "coke" for my liking.
Excess glucose will cause a diuresis if your insulin is not up to scratch but for most of us it is simply stored as glycogen.
As for carbon dioxide. This is an interesting one from the medical point of view. It is acidic and is taken via the alimentary tract in supersaturated solution. What little is dissolved in the blood will be excreted by the lungs. However I suspect the vast majority of the CO2 in such drinks immediately comes out of solution in the stomach because the hydrochloric acid drives it out of solution, chemically.
I suspect the worry is that as it forms a pocket of gas in the stomach there is an attendant risk of gastrointestinal barotrauma (burst stomach) on subsequent dives.
Alcohol is a powerful diuretic and so should be avoided if no other reason.
This old "codger" always takes a litre bottle of still spring water with him on a dive trip and I drink the lot and find my bladder and dry suit not to be a major problem bearingboy!
Hope this helps.
Paul
Here I am for the second time after my winter hybernation.
Like Ralph, I am somewhat amused by all the theories about why we should not drink carbonated or other specified beverages during a diving trip.
Like so many recommendations I suspect in the dim and distant past there were very good reasons to suggest that these were not so good for you when diving. Perhaps this harks back to the days when cokes contained the actual stimulant after which they are named!
If I can bring this discussion down to earth with a bump may I say that the fit human body is pretty good at maintaining itself in physiological balance (homeostasis). I believe this discussion is about the choice of beverage during a dive trip in order to maintain hydration because dehydration predisposes to DCI.
It should not about the treatment or prevention of dehydration in the clinical sense, which is where products like paedialyte (dioralyte/rehydrat in the UK) and gatorate are indicated. The former are designed to prevent dehydration and salt loss in pyrexial infants and children with diarrhoea and vomiting and, if gatrorate is what I think it is, it is to prevent "stokers cramps" by replacing the salts (and fluids) lost by excessive perspiration in a hot environment, such as a ship's boiler room or tropical rain forest.
Submersion itself directly causes a considerable diuresis and the gas used in open circuit scuba is dry. Thus without an above-average fluid intake during a dive trip the diver will become relatively dehydrated, but by itself this is not a danger.
Mixing this with unconservative dive profiles or a DCI hit is another matter.
Unless you drink a good qauntity of hypertonic solution such as sea water or ingest a powerful diuretic I believe I am right in suggesting that all the usual beverages will be beneficial and rehydrate you, some better than others and some more pleasantly than others!
Caffeine causes a diuresis and is a stimulant so is not really recommended but boy doesn't a hot cup of tea or coffee make you feel so much better after a cold dip in the North Sea! I'll happily take my chances with that one but there is far too much caffeine in "coke" for my liking.
Excess glucose will cause a diuresis if your insulin is not up to scratch but for most of us it is simply stored as glycogen.
As for carbon dioxide. This is an interesting one from the medical point of view. It is acidic and is taken via the alimentary tract in supersaturated solution. What little is dissolved in the blood will be excreted by the lungs. However I suspect the vast majority of the CO2 in such drinks immediately comes out of solution in the stomach because the hydrochloric acid drives it out of solution, chemically.
I suspect the worry is that as it forms a pocket of gas in the stomach there is an attendant risk of gastrointestinal barotrauma (burst stomach) on subsequent dives.
Alcohol is a powerful diuretic and so should be avoided if no other reason.
This old "codger" always takes a litre bottle of still spring water with him on a dive trip and I drink the lot and find my bladder and dry suit not to be a major problem bearingboy!
Hope this helps.
Paul
