Free water restriction

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Specializes in cardiac rehab, medical/tele, psychiatric.

Can anyone explain to me? I had a pt with hyponatremia (not sure which type), she had apparently been taking laxatives and drinking a ton of water..and we put on a free water restriction. I am not understaning why they can have other fluids which contain water but not "free water".

Thanks!

Specializes in Nephrology, Cardiology, ER, ICU.
Specializes in LTAC, Telemetry, Thoracic Surgery, ED.

Simple explaination: Free water would contribute to the hemodilution. Other beverages have sodium and other things in them. That's why sometimes you'll see someone on a fluid restriction and bet getting IVF.

Specializes in Family Nurse Practitioner.

hyponatremia, a NA level lower than 135

can be associated with syndrome of inappropiate antidiuretic hormone ie aldosterone. aldosterone is causes the body to retain water, causes of this include head trauma, renal failure, sickness in the elderly

Addisons dz is the other culprit, this happens when adrenal glands dont make enough cortisol.

treatment involves restoring sodium balance, prevent the K from getting to high

you wanna watch the urine for osmolarity,

Patients should be monitored in a ICU during the acute phase IMO

Fluid restrictions occur with SAIDH and demeocyline.. this antibiotic helps restore normal ADH levels

Specializes in LTC, home health, critical care, pulmonary nursing.
hyponatremia, a NA level lower than 135

can be associated with syndrome of inappropiate antidiuretic hormone ie aldosterone. aldosterone is causes the body to retain water, causes of this include head trauma, renal failure, sickness in the elderly

Addisons dz is the other culprit, this happens when adrenal glands dont make enough cortisol.

treatment involves restoring sodium balance, prevent the K from getting to high

you wanna watch the urine for osmolarity,

Patients should be monitored in a ICU during the acute phase IMO

Fluid restrictions occur with SAIDH and demeocyline.. this antibiotic helps restore normal ADH levels

The patient the OP referred to sounds a lot like he or she has an eating disorder.

Specializes in Family Nurse Practitioner.
The patient the OP referred to sounds a lot like he or she has an eating disorder.

sounds like psychogenic polydipsia then

Specializes in psych, addictions, hospice, education.

maybe she drinks water to feel full so she won't eat anything with calories in it

Specializes in Medical.

We get a lot of psychogenic polydipsia - having a low Na+ makes them feel good.

having a low Na+ makes them feel good.

Why?

...

Specializes in psych, addictions, hospice, education.

How would someone with psychogenic polydipsia know that drinking lots of water would yield low sodium?

Specializes in Medical.

I have no idea how I knew this, having a fly-paper memory for facts but not their origins. I had the idea that some brain chemistries have a dopaminergic response but when I googled I could find anything, making me thing I was - heaven forfend - wrong!

Then I searched for "water intoxication"; usually inadvertent, I narrowed it down with "self induced" and found this abstract about the use of naloxone in polydipsic schitzophrenic patients that concluded: "naloxone seems to be a potential treatment for psychiatric patients displaying self-induced water intoxication and that endogenous opioid systems are involved in the compulsive drinking behavior of this syndrome."

This was supported by another report that states: "There seems to be a direct link between water intake and an increase in the activity of the dopaminergic system. Thus in these patients, drinking excessive amounts of water would result in the reward of endogenous opioids being released in the brain. It basically puts them on a high."

So - for some people with an already altered brain chemistry (ie psychiatric conditions like schitzophrenia), an increase in water consumption lowers their serum sodium, resulting in increased dopaminergic response, releasing naturally-occuring opioids, which makes them feel good and/or high.

I imagine they don't know anything about the chemistry of it and just know it happens when they drink a lot of water. I thought it was interesting that psychiatric inpatients already drink a higher amount of water than the general population.

Unfortunately it's really risky - drop your Na+ below 120 and it's potentially fatal.

Specializes in psych, addictions, hospice, education.

I agree with all you wrote, taxalandra, just didn't know where the low sodium came in. Definitely if someone is hypervolemic, he/she is hyponatremic, if the body is working "normally." Water dilutes sodium. I'm thinking the psychogenice polydipsia has more to do with opioid receptors being happy due to lots of things, not just sodium-lack.

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