Published Jul 2, 2007
kimber3ks, ASN, BSN, RN, EMT-B
71 Posts
I am trying to get straight between the different types of IV solutions:
ISOtonic, HYPER and HYPO tonic and when you would give one versus the other
I know that 0.9 NS and LR are isotonic and are used most often.
When you give the only HYPOtonicn solution of 0.45% NS
and when for the HYPERs with all of the D5s, etc???
I presume it has to do with what TYPE of dehydration they have, and I also know that the MD is the one to figure that out and orders the appropriate med, but I feel like I SHOULD know WHY a patient is getting one fluid over another.
TIA,
Kim
Daytonite, BSN, RN
1 Article; 14,604 Posts
hi, kim. one of the things i'm supposed to do this summer is create a chart that lists the various hypotonic, hypertonic and isotonic iv solutions and what they are used for. it's just not completed yet, so your question is kind of forcing my hand here in trying to answer your question. i may be giving you more information than you wanted but your question encompasses fluids and electrolytes as well as iv fluids themselves. much of the information below comes from intravenous therapy: clinical principles and practice, edited by judy terry, leslie baranowski, rose anne lonsway and carolyn hedrick, a book that was written for the intravenous nurses society in 1995. i've tried to give you some specific information on dehydration that merges with iv therapy and iv infusion.
[*]isotonic solutions
[*]hypertonic solutions
basically
[*]5% dextrose in one liter of water contains 5 grams of dextrose per every 100ml which gives 170 calories per liter of fluid (this was a question on my state board exam in 1975).
[*]free water - the dextrose in iv solutions is metabolized very rapidly since it is a simple sugar which leaves behind plain old water. this water is able to cross all cell and tissue membranes to go into the various fluid compartments where is it needed.
[*]the higher percentage dextrose solutions are used to supply the patient with calories and often need to be given via a central iv line.
[*]hypovolemia occurs in acute pancreatitis.
[*]always review your patient's laboratory tests to determine if the iv solution is appropriate, particularly
[*]arterial blood gasses for the
dehydration may also be called fluid volume deficit or hypovolemia and is due to:
ammonthenephite
24 Posts
wow.......I'm a pre-nursing student and just ran across this. Had to tell myself to take a deep breath and just take baby steps.....get that A&P done first.......lol:)
Uber excited though, can't wait for stuff like this!!
Jutay24
1 Post
Daytonite
The amount of that information was unnecessary. Thank you for not breaking it down...and thank you for copying and pasting.
Double-Helix, BSN, RN
3,377 Posts
I'm going to try to make this as simple as possible, but it's necessary to give a little information about osmolarity.
Hypo, Iso and Hyper tonic solutions all are compared to the osmolarity, or concentration of particles in liquid, of blood plasma. Think of osmolarity as the amount of grains of salt in a cup of water. Particles can never move, only the fluid can. The fluid wants to balance out the number of particles in the veins and outside the veins. It does this by moving between the veins and the cells.
Isotonic solutions are the easiest. They contain the same amount of particles as blood plasma. So if you had a cup of Isotonic solution and a cup of blood, they would contain the same amount of salt. Because the osmolarity is the same, isotonic solutions stay in the blood stream. So when you give an isotonic solution, it increases the amount of fluid in the veins. This is good for someone who has lost a lot of blood or has low blood pressure due.
Hypotonic solutions have fewer particles than blood. So when you give a hypotonic solution, you have more water and fewer particles in the blood. To balance this, the body shifts fluid out of the veins and into the cells. So hypotonic solutions hydrate cells.
Hypertonic solutions contain a higher concentration of particles than blood plasma. So when you give hypertonic solutions, the body balances out by pulling fluid from the cells and interstitial (between cells) space and into the vascular system. Hypertonic solutions increase the amount of fluid in the veins by pulling fluid from the cells and interstitial space. This might be helpful if a patient has edema.
There are plenty of places online that you can find a list of which solutions are hyper, hypo, iso, so I'm not going to list them. But be careful with solutions that contain glucose (D5 or D10). Glucose is used within minutes of entering the blood stream, so you are left with the base solution. For example, D5 NS is hypertonic in the bag, but the glucose is used to quickly that you are left with the base solution, NS, which is isotonic. D5 0.45NS is hypertonic in the bag, but once the glucose is used you are left with 0.45 NS, which is hypotonic.
akulahawkRN, ADN, RN, EMT-P
3,523 Posts
The only thing I can add to what Ashley stated (which is a good description) is to think about where you want the water in the IV solution to go. Do you need it to replenish intracellular and intercellular fluid? Do you simply need to top off the vascular compartment? Do you need to fill up the vascular compartment and the other compartments are basically OK or at the expense of the other compartments?
On top of all that, the fluid that's appropriate now might not be appropriate in a few hours. That's what reassessment is for...