The Iceni
Medical Moderator
Hi all,
I believe there are two distinct problems associated with excessive fluid intake.
The first is fluid overload, as Dr Vikingo touched upon, which is unlikely to occur in healthy subjects drinking "reasonable" quantities over a short period of time, such as before or after a dive.
The second is a mismatch between fluid and elecrolyte loss and their replacement. In clinical practice this is seen in
a) Diarrhoeal and vomiting illnesses, and
b) Extremes of heat and humidity (and pyrexia).
In both cases the electrolyte (salt) loss exceeds intake if salts are not taken with the water that is ingested to replace its loss. In the first case the salts are lost in the vomitus and excrement. In the second in the sensible perspiration (sweating).
In a hot environment, a considerable amount of sodium is lost in sensible perspiration (at least in an unadapted individual new to that environment) and water mustbe ingested to prevent heat exhaustion or heat stroke.
If this salt is not replaced, the result is a dilution of the body's sodium content and as one of the earlier contributors rightly states, the healthy body attempts to reverse this by taking these salts from the tissues. This results in an increase in extracellular calcium, which leads to involuntary muscle spasms, or cramps, which I have discussed before.
In canning factories and other hot environments, such as mines and boiler rooms, our Health and Safety at Work Act obliges employers to provide accessible electrolyte-rich rehydration fluid at the work place to prevent such problems.
For the vast majority of healthy divers I very much doubt either clinical manifestation will appear, unless perhaps you sit in your dry suit for hours on end in the hot sun (sufficient perhaps to soak the inside of your boots with perspiration) and then drink large quantities of water, containing no salt or sugar.
An interesting physiological phenomenon.
Hope this helps.
Regards,
Paul
I believe there are two distinct problems associated with excessive fluid intake.
The first is fluid overload, as Dr Vikingo touched upon, which is unlikely to occur in healthy subjects drinking "reasonable" quantities over a short period of time, such as before or after a dive.
The second is a mismatch between fluid and elecrolyte loss and their replacement. In clinical practice this is seen in
a) Diarrhoeal and vomiting illnesses, and
b) Extremes of heat and humidity (and pyrexia).
In both cases the electrolyte (salt) loss exceeds intake if salts are not taken with the water that is ingested to replace its loss. In the first case the salts are lost in the vomitus and excrement. In the second in the sensible perspiration (sweating).
In a hot environment, a considerable amount of sodium is lost in sensible perspiration (at least in an unadapted individual new to that environment) and water mustbe ingested to prevent heat exhaustion or heat stroke.
If this salt is not replaced, the result is a dilution of the body's sodium content and as one of the earlier contributors rightly states, the healthy body attempts to reverse this by taking these salts from the tissues. This results in an increase in extracellular calcium, which leads to involuntary muscle spasms, or cramps, which I have discussed before.
In canning factories and other hot environments, such as mines and boiler rooms, our Health and Safety at Work Act obliges employers to provide accessible electrolyte-rich rehydration fluid at the work place to prevent such problems.
For the vast majority of healthy divers I very much doubt either clinical manifestation will appear, unless perhaps you sit in your dry suit for hours on end in the hot sun (sufficient perhaps to soak the inside of your boots with perspiration) and then drink large quantities of water, containing no salt or sugar.
An interesting physiological phenomenon.
Hope this helps.
Regards,
Paul
