IV Therapy

Isotonic Normal Saline (NS)

Used to replace body fluids

Hypertonic More concentrated than plasma

Used to draw water from tissue

Hypotonic Less concentrated than plasma

Used to rehydrate tissue

there is a good thread in the nursing student assistance forums / called

any good iv therapy or nursing procedure web sites

it's got a ton of good info and web sites. you should try this thread. i start ns on jan. 17 and by reading this thread i already know tons of stuff. hope this helps and good luck.

Does anyone out there have cool memory aids or tricks for remembering which IV fluid is used for particular therapies?

Also, I seem to be forgetting how hypertonic and hypotonic solutions effect the body. Does anyone have a cool way of explaining it?

I've read about it lots, but am having a difficult way of retaining the information (maybe its just the way its been presented? Not sure)...

Any help will be much appreciated!:heartbeat:heartbeat

Babybird,

The osmolarity or tonicity of an IV solution is compared to what normal serum osmolarity is. Normal serum osmolarity is approx. 290 (serum).

So, for a solution to be isotonic (most like blood plasma) it can have an osmolarity of + or - 50 on either side of the 290. In other words, an isotonic solution can have an osmo. of 240-340.

Look at your IV fluid bags... Usually within the first five "lines" in the paragraph below the named fluid, it will give you its osmolarity.

Anything above 340 is Hypertonic, and below 240 is hypotonic.

An isotonic fluid will just expand the vascular space. However, one way of looking at a hypertonic solution that makes sense to most is that a hypertonic solution is one in which it has more "salt" than water. If a solution has more salt, it will draw fluid into itself.. So, this solution in a vein will cause fluids to be drawn out of the cells and interstitial spaces and into the vein, or vascular space.

In contrast, a hypotonic solution, has less "salt" than water and therefore,

fluid will leave the vascular space and go out and "bathe" the interstitial and the cells.

Remember the body always wants that equilibrium or homeostasis.

So, someone with cellular dehydration would do well to get a hypotonic fluid, but someone who has edema (perhaps from surgery shifts) may need a hypertonic fluid to help "pull" the fluid out of the cells and interstitial spaces and back into the blood vessel where the body can pass it through the kidneys for elimination.

Hope this helps!

:loveya:

I read this one somewhere on allnurses, and it really helps me remember.

hypo= hippo

With hypo tonic solutions, there is more water than solutes. To maintain a balance, water leaves the vascular system and goes into the cells. Your cells swell like fat hippos.

Works for me. Especially when I imagine fat little hippo cells. :chuckle

read this one somewhere on allnurses, and it really helps me remember.

hypo= hippo

"With hypo tonic solutions, there is more water than solutes. To maintain a balance, water leaves the vascular system and goes into the cells. Your cells swell like fat hippos.

Works for me. Especially when I imagine fat little hippo cells." :chuckle

To add to this hypertonic solution makes the cells shrink, while isotonic solution is good for everyone that has normal osmolarity and hypotonic solution can cause the cells to burst.