free water

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In regards to NG tube, what does the term free water mean?

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Specializes in Geriatrics.

As far as I understand it's water that is necessary for hydration, in other words the water you would drink on a daily basis to prevent dehydrating yourself. For me that's roughly 2000cc/day. If I was unable to drink and was relying solely on the NG tube for nourishment and hydration, the free water would be used in place of my oral fluids. I could be wrong and I am sure its probably a bit more complicated than that but that's the way I understand it?

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Specializes in critcal care, CRNA.
In regards to NG tube what does the term free water mean?[/quote']

We had a formula with our tube feed. The machine would give tube feed followed by water every so often.

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Free water is water without solutes-- plain, ordinary water. Bouillon, for example, is not free water. NS is not free water. Juice is not free water.

People who have low serum sodium are often on a free water restriction. Why is that?

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Specializes in Geriatrics.
Free water is water without solutes-- plain, ordinary water. Bouillon, for example, is not free water. NS is not free water. Juice is not free water.

People who have low serum sodium are often on a free water restriction. Why is that?

I always enjoy reading your posts. I knew it was more complicated. I have dubbed you the fluid queen. Your posts helped me pass my fluid test. :)

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I always enjoy reading your posts. I knew it was more complicated. I have dubbed you the fluid queen. Your posts helped me pass my fluid test. :)

Happy to hear it! You have made my day.

Now, tell the OP why people with low serum Na+ are on free water restrictions! (You know how I cranky I get about memorize-for-the-test-and-forget-it!!)

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Specializes in Forensic Psych.
Free water is water without solutes-- plain ordinary water. Bouillon, for example, is not free water. NS is not free water. Juice is not free water. People who have low serum sodium are often on a free water restriction. Why is that? [/quote']

Huh. For some reason I thought it meant "all the water you want!"

Learn something (or multiple somethings in this field) every day!

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Specializes in Geriatrics.
Happy to hear it! You have made my day. Now tell the OP why people with low serum Na+ are on free water restrictions! (You know how I cranky I get about memorize-for-the-test-and-forget-it!!)[/quote']

This is how out instructor explained it. When your electrolytes are imbalanced you don't want to add more of the opposite. Water and Na are buddies and need to balance so if your serum sodium is low you wouldn't want to make it a worse ratio by adding more of the opposite to the body... ie: water. It'll only cause a larger and worse imbalance. You would treat it by bringing the Na levels up, not the fluids to restore the balance.

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The short way to think about this is that serum sodium is not telling you about sodium; it really is telling you about water balance. Low water balance (de-hydrat-ion) makes the sodium more concentrated-> higher serum sodium. Water excess dilutes serum sodium -> lower serum sodium.

You change these not by adding or withholding sodium, but by regulating the water.

So someone with hyponatremia is usually on a free water restriction to prevent further dilution.

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The short way to think about this is that serum sodium is not telling you about sodium; it really is telling you about water balance. Low water balance (de-hydrat-ion) makes the sodium more concentrated-> higher serum sodium. Water excess dilutes serum sodium -> lower serum sodium. You change these not by adding or withholding sodium but by regulating the water. So someone with hyponatremia is usually on a free water restriction to prevent further dilution.[/quote']

And just like that, GrnTea rocked.

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Specializes in Geriatrics.
The short way to think about this is that serum sodium is not telling you about sodium; it really is telling you about water balance. Low water balance (de-hydrat-ion) makes the sodium more concentrated-> higher serum sodium. Water excess dilutes serum sodium -> lower serum sodium. You change these not by adding or withholding sodium but by regulating the water. So someone with hyponatremia is usually on a free water restriction to prevent further dilution.[/quote']

See why you're the fluid queen? We were really only taught the gist of it and I literally took my test a few days ago and also have yet to apply the knowledge. I learn better by applying the info. I do remember you stating serum sodium is not salt levels but rather fluid levels and normal saline is not salt water. :p

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Thank you for sharing. Low serum sodium is the ratio of sodium to water is low. To bring it back into balance, restrict H20. Would that also mean that there is fluid excess possibly edema? How do you go about memorizing the signs and symptoms of hyponatremia? I know it affects the nerve impulse and CNS mostly. We had an exam on the electrolytes and trying to memorize all the signs and symptoms were brutal.

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