IV fluids...need some help

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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

Specializes in med/surg, telemetry, IV therapy, mgmt.

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.

  • hypotonic solutions
    • 0.45% sodium chloride (osmolarity of 155, ph of 5.0 to 5.6) - replaces sodium, replaces chloride, and provides free water. contains 77meq of sodium and 77meq of chloride. used most often to hydrate patients and to treat hyperosmolar diabetes, metabolic alkalosis where there has been sodium depletion and fluid loss. when used continuously and exclusively, the patient needs to be monitored for hyponatremia and calorie depletion (there are no calories in this solution).

    [*]isotonic solutions

    • 2.5% dextrose and 0.45% sodium chloride (osmolarity of 280, ph of about 4.0 to 4.5) - provides calories and free water
    • 5% dextrose and 0.11% sodium chloride (osmolarity of 290, ph of about 4.3) - provides calories and free water, provides some sodium and chloride
    • 0.9% sodium chloride (osmolarity of 308, ph of 5.7) - primarily used to replace sodium and chloride, treats hyperosmolar diabetes, metabolic alkalosis where there has been sodium depletion and fluid loss. the reason for it's used with blood transfusion is because it will not hemolyze erythrocytes. often given as rapid bolus for fluid replacement during resuscitation.
    • 5% dextrose and water (osmolarity of 253, ph of about 4.5 to 5.0) - provides calories and free water.
    • normosol r [abbott] (osmolarity of 295, ph of 6.6) - provides electrolytes
    • plasmalyte a [baxter] (osmolarity of 294, ph of 7.4) - provides electrolytes
    • plasmalyte r [baxter] (osmolarity of 312, ph of 4.0 to 6.5) - provides electrolytes. also contains sodium lactate which is used in treating mild to moderate metabolic acidosis.
    • isolyte e [mcgaw] (osmolarity of 315, ph of 6.0) - provides electrolytes
    • ringer's (osmolarity of 310, ph of 5.5 to 5.8) - it's content is very similar to plasma, but should not be used continuously since it contains no calories and could result in an excessive amount of one or more of the electrolytes it contains. it's components include sodium, chloride, potassium and calcium. it is used to replace electrolytes and to hydrate, often where there has been extracellular fluid loss. adding dextrose increases the osmolarity of the solution and lowers it's ph making it a hypertonic solution.
    • lactated ringer's [also known as hartmann's solution] (osmolarity of 275, ph of 6.5 to 6.6) - as with ringer's, it's content is very similar to plasma, but should not be used continuously since it could result in an excessive amount of one or more of the electrolytes it contains. it's components include sodium, chloride, potassium, calcium and sodium lactate which is used to replace electrolytes and to hydrate, often used where there has been extracellular fluid loss. it is used in treating mild to moderate metabolic acidosis and hypovolemia. often given as rapid bolus for fluid replacement during resuscitation. since lactate is metabolized in the liver it shouldn't be used in patients with hepatic diseases. using it in a patient with lactic acidosis will overload the person's buffering system. adding dextrose also increases the osmolarity of the solution and lowers it's ph making it a hypertonic solution.
    • 2.5% dextrose in half strength lactated ringer's (osmolarity of 263, ph of 5.0) - provides calories and free water, provides electrolytes. also contains sodium lactate which is used in treating mild to moderate metabolic acidosis. also see the information above with lactated ringers.
    • 6% dextran and 0.9% sodium chloride (osmolarity of 308, ph of 4.0 to 4.5) - 6% dextran is a high molecular weight solution. the nacl replaces sodium and chloride. treats hyperosmolar diabetes, metabolic alkalosis where there has been sodium depletion and fluid loss. it draws fluid into the vascular system. dextran is a plasma expander that is given for shock or anticipated shock related to trauma, surgery, burns or hemorrhage, and for the prophylactic prevention of venous thrombosis and pulmonary embolism during surgery. it should not be used as a blood substitute except in emergencies when blood is not available. it's volume expansion effect lasts for approximately 24 hours during which the dextran is slowly broken down to glucose and metabolized into carbon dioxide and water. complications with the use of this solution include anaphylactic reaction, wheezing, tightness in the chest, gi problems of nausea and vomiting, circulatory overload and tissue dehydration. if blood transfusion is intended, the type and cross match needs to be done before this solution is started. because dextran pulls fluid into the vascular system it will result in altered blood tests.
    • 10% dextran and 0.9% sodium chloride (osmolarity of 252, ph of 4.0 to 4.5) - 10% dextran is a low molecular weight dextran. it is used in treating shock related to vascular system fluid losses such as in burns, trauma, hemorrhage and surgery. it is also used for the prophylactic prevention of venous thrombosis and pulmonary embolism during surgery. complications include circulatory overload that results in various kinds of congestion and increased bleeding time. as with the 6% dextran solutions, subsequent laboratory blood tests will be altered due to it entering the vascular system. this dextran is excreted through the renal system within 24 hours.

    [*]hypertonic solutions

    • 5% dextrose and 0.2% sodium chloride (osmolarity of 320, ph of 4.0 to 4.4) - provides calories and water, replaces sodium and chloride. this is given for fluid replacement.
    • 5% dextrose and 0.3% sodium chloride (osmolarity of 365, ph of 4.0 to 4.4) - provides calories and water, replaces sodium and chloride
    • 5% dextrose and 0.45% sodium chloride (osmolarity of 405, ph of 4.0 to 4.4) - provides calories and water, replaces sodium and chloride. this is given for fluid replacement.
    • 5% dextrose and 0.9% sodium chloride (osmolarity of 560, ph of 4.0 to 4.4) - provides calories and water, replaces sodium and chloride. this is given for fluid replacement.
    • 10% dextrose and 0.2% sodium chloride (osmolarity of 575, ph of 4.3) - provides calories and water, replaces sodium and chloride
    • 10% dextrose and 0.45% sodium chloride (osmolarity of 660, ph of 4.3) - provides calories and water, replaces sodium and chloride
    • 10% dextrose and 0.9% sodium chloride (osmolarity of 815, ph of 4.0 to 4.3) - provides calories and water, replaces sodium and chloride
    • 3% sodium chloride (osmolarity of 1030, ph of 5.0) - used to replace severe sodium and chloride losses. other conditions it might be used for are excessive sweating, vomiting, renal impairment and excessive water intake where hyponatremia has occurred.
    • 5% sodium chloride (osmolarity of 1710, ph of 5.0 to 5.8) - used to replace severe sodium and chloride losses. other conditions it might be used for are excessive sweating, vomiting, renal impairment and excessive water intake where hyponatremia has occurred.
    • 10% dextrose and water (osmolarity of 505, ph of 4.3 to 4.5) - provides calories and water
    • 50% dextrose and water (osmolarity of 2526, ph of 4.0 to 4.2) - provides calories and water
    • 5% dextrose in ringer's (osmolarity of 562, ph of 4.3) - provides calories and free water, provides electrolytes. also see the information above with ringer's
    • 5% dextrose in lactated ringer's (osmolarity of 527, ph of 4.9) - provides calories and free water, provides electrolytes. also contains sodium lactate which is used in treating mild to moderate metabolic acidosis. also see the information above with lactated ringers.
    • 5% dextrose and 5% alcohol (osmolarity of 1114, ph of 4.5) - provides calories and free water
    • 5% sodium bicarbonate injection (osmolarity of 1190, ph of 8.0) - is an alkalizing solution that is used to treat metabolic acidosis associated with renal disease and cardiac arrest. the sodium in the solution is an antagonist to the cardiac effects of potassium. it is also used in severe hyperkalemia. it maintains osmotic pressure and acid-base balance. the major complications associated with it's use are related to electrolytes and include metabolic alkalosis, hypocalcemia, hypokalemia, water and sodium retention that cause hypernatremia, other electrolyte imbalances and iv site extravasation that causes chemical cellulitis, necrosis, ulceration and sloughing of the skin.
    • 1/6 m(olar) sodium lactate (osmolarity of 335, ph of 6.5) - contains sodium lactate which is used in treating mild to moderate metabolic acidosis.
    • 10% mannitol injection (osmolarity of 549, ph of 5.7) - mannitol is a sugar alcohol colloid and a plasma expander. it promotes diuresis by drawing fluid from the cells into the plasma. it acts rapidly and is excreted within 3 hours through the kidneys. it is primarily used for intracranial pressure and cerebral edema where it acts within 15 minutes of being infused. it will also be used during the oliguric phase of acute renal failure to promote the excretion of toxic substances from the body. in high intraocular pressure, it pulls fluid from the anterior chamber of the eye within 30 to 60 minutes of infusion. complications include frequent and severe fluid and electrolyte imbalances, cell dehydration, fluid overload, skin extravasation and necrosis with infiltration of the iv site, precipitate formation in the iv line and altered laboratory blood tests. the patient's blood tests should be monitored when the patient is receiving mannitol.
    • 15% mannitol injection (osmolarity of 823, ph of 5.7) - mannitol is a sugar alcohol colloid and a plasma expander. it promotes diuresis by drawing fluid from the cells into the plasma. it acts rapidly and is excreted within 3 hours through the kidneys. it is primarily used for intracranial pressure and cerebral edema where it acts within 15 minutes of being infused. it will also be used during the oliguric phase of acute renal failure to promote the excretion of toxic substances from the body. in high intraocular pressure, it pulls fluid from the anterior chamber of the eye within 30 to 60 minutes of infusion. complications include frequent and severe fluid and electrolyte imbalances, cell dehydration, fluid overload, skin extravasation and necrosis with infiltration of the iv site, precipitate formation in the iv line and altered laboratory blood tests. the patient's blood tests should be monitored when the patient is receiving mannitol.
    • 20% mannitol injection (osmolarity of 1098, ph of 5.7) - mannitol is a sugar alcohol colloid and a plasma expander. it promotes diuresis by drawing fluid from the cells into the plasma. it acts rapidly and is excreted within 3 hours through the kidneys. it is primarily used for intracranial pressure and cerebral edema where it acts within 15 minutes of being infused. it will also be used during the oliguric phase of acute renal failure to promote the excretion of toxic substances from the body. in high intraocular pressure, it pulls fluid from the anterior chamber of the eye within 30 to 60 minutes of infusion. complications include frequent and severe fluid and electrolyte imbalances, cell dehydration, fluid overload, skin extravasation and necrosis with infiltration of the iv site, precipitate formation in the iv line and altered laboratory blood tests. the patient's blood tests should be monitored when the patient is receiving mannitol.

basically

  • the dextrose solutions also serve as diluents for the administration of many iv medications.
  • in general, the electrolyte solutions are isotonic. adding dextrose to them makes the resulting solution hypertonic.
  • sodium deficits occur in head injuries, siadh (syndrome of inappropriate antidiuretic hormone) and cirrhosis
  • i boldfaced the solutions with the lowest and highest osmolarity
  • problems with using iv solutions of strictly sodium chloride include
    • hyponatremia (with continuous infusions of 0.45%)
    • calorie depletion
    • hypernatremia (with continuous infusion of the higher percentage nacl solutions)
    • peripheral edema
    • an exhaustion of other body electrolytes
    • hyperchloremia

    [*]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

    • the bun (blood urea nitrogen) - normal: 10-20 mg/dl
    • serum creatinine - normal: 0.7-1.5 mg/dl
    • hematocrit - normal: 44-52% (male); 39-47% (female)
    • hemoglobin - normal: 13.5-18.0 g/dl (male); 12.0-16.0 g/dl
    • serum osmolality - normal: 280-295 mosm/kg
    • serum electrolytes
      • sodium - normal: 135-145 meq/liter
      • potassium - normal: 3.5-5.0 meq/liter
      • chloride - normal: 97-110 meq/liter
      • calcium - normal: 8.9-10.3 mg/dl, or 4.6-5.1 meq/liter
      • magnesium - normal: 1.3-2.1 meq/liter, or 1.8-3.0 mg/dl
      • phosphate - normal: 2.5-4.5 mg/dl, or 1.8-2.6 meq/liter (adults); 4.0-7.0 mg/dl, or 2.3-4.1 meq/liter (children)

      [*]arterial blood gasses for the

      • ph - normal: 7.35-7.45
      • pao2 - normal: 80-100 mm hg
      • paco2 - normal: 38-42 mm hg
      • bicarbonate - normal: 22-26 meq/liter
      • base excess - normal: -2 to +2

dehydration may also be called fluid volume deficit or hypovolemia and is due to:

  • excessive fluid and electrolyte losses from the extracellular compartment
  • loss of gi fluids due to vomiting, diarrhea, suctioning and fistulas
  • fluid lost through the skin as the body attempts to regulate it's temperature or trauma of the skin (burns, large open wounds, cuts).
  • loss of fluid through the renal system (these losses are usually excessive) by polyuria due to hyperglycemia, renal disorders, administration of osmotic diuretics, administration of concentrated iv solutions and tube feedings
  • hemorrhage which causes loss from the intracellular compartment
  • third spacing - the shift of fluid from the circulation to a space where it is trapped and cannot be exchanged with fluid in the extracellular space. there is no actual physical fluid loss but the involved fluid is basically "out of commission". this occurs in intestinal ileus
  • decreased fluid intake due to confusion, coma, very young age or very old age and not recognizing the sense of thirst

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!!

Daytonite

The amount of that information was unnecessary. Thank you for not breaking it down...and thank you for copying and pasting.

Specializes in PICU, Sedation/Radiology, PACU.

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.

Specializes in Emergency Department.

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... ;)

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