Awkward Question

[ozskipper]

Dehydration. We all know its a killer. We all know what fixes it. Water!

Most of us know, that in the case of severe dehydration, colonic irrigation (enema) can save a persons life. In fact one can even use tainted water that way.

But what about salt water? If tainted water full of nasty bacteria can be safely used "up there", can salt water also be used? Or is the colon/bowel still going to absorb the salt and pass it through the kidneys, ultimately killing the person?

Any medico's out there with experience or knowledge on this?

Cheers
Oz

[SurferShane]

One thing I can say is this is not as absurd a question as it sounds. In these situations you can’t afford to waste a drop of this precious commodity.

I have read one account of a group lost at sea in a life raft who did similar with salt tainted water gathered from the first of the rainfall using the raft’s canopy. Those who did fared better than the individual who refused.

[swagman]

I hope someone else can confirm but seem to recall the Smeatons (family adrift for months after boat sunk by whales off Chile years back) used salt water to rehydrate in this way. I believe one or both of them were doctors.

If nothing else, it would certainly bring a tear to my eyes.......

Cheers
JOHN

[David_Old_Jersey]

Originally Posted by swagman

If nothing else, it would certainly bring a tear to my eyes.......

Cheers
JOHN

I wouldn't use the bilge pump.............


My quick Googles says saltwater won't immediately kill ya (and saline up the jacksy seems quite popular ) - but freshwater water of course better to re-hydrate.

But I guess one of those things that is about moderation. a couple of pints might save your life - a couple of gallons every day for a week might kill ya

Pack a funnel into the liferaft

[marc2012]

Going to keep checking here.Hope we get to the bottom of this.Is this where the saying"the end is near"is derived from.marc

[Hudson Force]

The movement of water through membranes from high to low concentration (osmosis) is the process by which are tissues are hydrated by the normal ingestion of water and the transport by the blood to all our tissues. The saltwater, a hypertonic, solution compared to the "fresh' water would not be a fluid that has a higher concentration of water than our tissues and therefore would not result in water moving from the lumen of our colon into the body tissues. Likely, the salinity of the ocean water would be slightly greater than our blood and draw water out of our tissues. With the salt concentration of our blood being uniform throughout our body; if it doesn't work orally, it won't work in the colon. Someone might surprise me with knowledge that doesn't conform with this basic physiology, but it seems unlikely; although, there may be some active transport use of cellular energy occuring in the colon that pumps water against the natural gradient. I be interested in looking at this further.

[capt_douglas]

I read somewhere that sailors have mixed salt with fresh water in order to extend water use. They seem to think the small amounts of salt water (up to the amount of salt you might ingest in 24 hours) can be ingested with few problems.

No one I know of even considers drinking salt water as a main source of liquid. As for tainted water, I would consider it only as a last resort and even then would take the clean salt water over tainted/brackish any time.

The bottom line is that humans can live for weeks without food and only about 3 days without water. That would indicate to me that making sure you have enough water for the trip is a very high priority.

[tartansail]

There are two ways to ingest seawater -- at the top and at the bottom. The body's response will differ depending on the route of entry, but the end result will be the same -- further dehydration.

If you drink sea water, much of it is absorbed and increases the salt concentration in your blood stream and fluid outside cells. The salt increases the osmotic load in those fluids. Water will leave your body's cells to equilibrate with this increased osmotic load. The kidneys try to dump the excess salt. Unfortunately, while their capacity to concentrate salt into the urine is impressive, they can't achieve the salt concentration of sea water. As a result, more water than salt is excreted leading to worsening dehydration.

Not all the salt water is absorbed so it will move downstream to where it meets the water put in the, um, other way. In the colon, the body usually tries to absorb water before leaving semi-solids behind. Unfortunately, it uses osmosis to help achieve this and the osmotic effect is a two way street. If there is a higher concentration of salt in the colon than the blood and extracellular fluid, water flows from body to colon to out causing osmotic diarrhea and further dehydration.

Unfortunately, at ocean salt concentrations, the "Water, water everywhere nor any drop to drink." adage is true.

[speciald@ocens.]

My wife threatens crew before a trip with her turkey baster should any of them get really seasick. Actually the best fluids to use are Pedealyte (?s, a fluid used for dehydrated babies) or diluted Gatorade. Sea water would probably worsen the situation.

[GordMay]

Originally Posted by ozskipper

Dehydration. We all know its a killer. We all know what fixes it. Water!

Most of us know, that in the case of severe dehydration, colonic irrigation (enema) can save a persons life. In fact one can even use tainted water that way ...

I didn't/don't know. In fact, I though that one of the possible side effects of colonic irrigation was dehydration.

[rtbates]

absolutely. survivors have also stayed alive by drinking their urine..And a Brit cossed the Atlantic solely drinking saltwater...

[Cormorant]

The Robertsons ("Survive the Savage Sea") used brackish unpalatable water from the floor of their raft when they administered enemas, not pure sea water.

A rough guesstimate would take into consideration these two facts: the salinity of human blood is about 0.9%. (Not sure how much that goes up in an extreme dehydration situation.) The salinity of seawater is about 3.5%. So -- just guessing here -- you'd want to mix in about 3 parts fresh to 1 part seawater to have a solution that wouldn't create a negative osmotic gradient in your colon.