[DAMomma]

osmolality. osmosis, isotonic, hypertonic, hypotonic....... I am actually trying to read ahead for this subject. I am confusing the hell out of myself. The lecture will be in 2 more weeks......I am running into major anxiety here. Please tell me it is going to be okay. FEAR of the unknown.

I need a hug

Am I over catastrophe (catastrosizing?) here? I can't get the search thing to work here on all nurses so I can't see if there were prior post to help understand this.

I learned blood plasma osmolarity is about 290mOsm/L

[CritterLover]

Yes, I think you are making this too hard.

Osmolality tells you how concentrated a solution is.

A hypotonic solution is less concentrated than blood. (Think of weak tea)

A hypertonic solution is more concentrated than blood. (Think of syrup)

An isotonic solution is the same concentration as blood. (Think of ocean water)

Osmosis is the diffusion of water. Diffusion is a passive (doesn't require energy input) process by which a solution tends to "even out" concentrations accross a "semi-permiable membrane." (Think cell membrane).

This is important because if you add a hypotonic IV solution to blood (such as sterile water), the red blood cells tend to swell because the extra water from the solution will diffuse into the RBCs in an attempt to even out the concentration, since the hypotonic solution will make the blood less concentrated. (As an aside, those RBCs could swell to the point they rupture).

If you add a hypertonic IV solution to blood (such as 10% dextrose), the RBCs tend to shrivel up, because water will leave the RBCs in an attempt to even out the concentration, since the hypertonic solution will make the blood more concentrated.

How much these things happen will depend greatly on how hypertonic or hypotonic the solution is.

Does this help?

[onduty23]

hypo tonic has less solute it has more fluids

hyper tonic more fluid less soilute

isotonic has same of amount

hypertonic fluids pull fluids towards itself to dilute the its already high solute content
hypotonic fluid give its fluid so it can be use to dilute

so let say i put a hypertonic solution next to the body cells it would shrink the cell of fluids so it can dilute itself

whereas if i put a hypotonic fluid next to a body cell it would give away fluid to the cell so the cell would enlarge

hyper takes
hypo gives

[Daytonite]

DAMomma. . .I had to laugh when I read your post. You shouldn't do this to yourself, but I understand that you are enthusiastic and are like a sponge and want to know about everything--yesterday! Yes, it's going to be OK. Hug. I was an IV therapist for many years. Fortunately, I did a bit of surfing some time ago to find information on this subject. Also, I happen to like Fluid & Electrolyte Balance: Nursing Considerations (now in it's 4th edition) by Norma M. Metheny as my poison. It explains all these concepts and includes information on IV solutions as well. I've never looked at the "made easy" or "dummies" books on this subject so I can't speak to them. Matheny's book has been around for a long, long time and she is definitely someone who knows her "Ps" and "Qs" about this subject.

There was a very nice site that listed the various IV solutions and the electrolytes that were in them and whether they were isotonic, hypertonic or hypotonic. However, that site was shut down and the article is no longer available. Creating one of these tables is something I'll have to put on my ToDo list for the future.

http://www.indstate.edu/mary/Fluidlytecf/index.htm - a slide show presentation on fluid and electrolytes. Covers sodium, potassium and calcium and treatment including IV fluids.

http://www.indstate.edu/mary/n205.htm - this is the home page for the above site. The link to the above is at the bottom of this page. There are more links there to information on fluids and electrolytes including lecture note outlines

http://connection.lww.com/Products/Taylor5e/ClinSim/Tutorial.html - Fluid and Electrolytes tutorial from Taylor's Fundamentals of Nursing student resources website. You will need to register and create a user name and ID, but the tutorial is free.

Here are a couple of older allnurses threads with information about IV electrolytes. One has lots of links I listed on electrolyte, ABG and alkalosis/acidosis resources:

http://allnurses.com/forums/f50/flui...es-200537.html
http://allnurses.com/forums/f205/one...on-196672.html
http://allnurses.com/forums/f205/iv-fluids-189983.html

[NRSKarenRN]

Great analogies Critter Lover--refreshed my crowded brain too!

[DutchgirlRN]

Critterlover, Thanks for the simple, easy to understand refresher! To the OP, us old nurses still get confused. Take Heart!

[DAMomma]

Thanks you guys....I just had to step back and calm down. Daytonite....you know me too well . I did feel like I wanted to know EVERYTHING yestereday. I am going to check out those incredibly easy books to help me. Why am I freakin out? I do have spring break of no classes to really sit down to figures this out. I am finding that I really love the science aspect of nursing and I am hard on myself when I "think" I will not be able to grasp something.

I just had to vent....I am demented....

[Daytonite]

Originally Posted by DAMomma

I just had to vent....I am demented....

We all were and are. That's why we went or are going into this profession!

[Danish]

Originally Posted by CritterLover

Yes, I think you are making this too hard.

Osmolality tells you how concentrated a solution is.

A hypotonic solution is less concentrated than blood. (Think of weak tea)

A hypertonic solution is more concentrated than blood. (Think of syrup)

An isotonic solution is the same concentration as blood. (Think of ocean water)

Osmosis is the diffusion of water. Diffusion is a passive (doesn't require energy input) process by which a solution tends to "even out" concentrations accross a "semi-permiable membrane." (Think cell membrane).

This is important because if you add a hypotonic IV solution to blood (such as sterile water), the red blood cells tend to swell because the extra water from the solution will diffuse into the RBCs in an attempt to even out the concentration, since the hypotonic solution will make the blood less concentrated. (As an aside, those RBCs could swell to the point they rupture).

If you add a hypertonic IV solution to blood (such as 10% dextrose), the RBCs tend to shrivel up, because water will leave the RBCs in an attempt to even out the concentration, since the hypertonic solution will make the blood more concentrated.

How much these things happen will depend greatly on how hypertonic or hypotonic the solution is.

Does this help?

I dont know about the OP, but you summarized it well for me

[Scoobiedoo]

So,
What solutions ARE:

Hypo Iso Hpyer

Where do LR, NS, 1/2 NS, D5W fit in?



???