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IV Fluids
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IV fluids are utilized for resuscitation, to replace fluid losses, and for maintenance hydration in patients who are not able or not allowed to drink water. Like all prescribed medications, IV fluids have benefits and risks. Fluid therapy should be carefully administered, with specific goals or end points established to avoid inadvertent fluid overload or acid-base alterations.
Crystalloids
Crystalloid solutions contain small molecules that flow easily across semipermeable membranes, from the bloodstream into the cells and body tissues. Crystalloid solutions are distinguished by the relative tonicity (before infusion) in relation to plasma and are categorized as isotonic, hypotonic, or hypertonic.
Isotonic solutions
Isotonic solutions have a concentration of dissolved particles similar to plasma, and an osmolality of 250 to 375 mOsm/L. These fluids remain within the extracellular compartment and are distributed between intravascular (blood vessels) and interstitial (tissue) spaces, increasing intravascular volume. They are used primarily to treat fluid volume deficit.
General nursing considerations:
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Document baseline vital signs, edema, lung sounds, and heart sounds, and continue monitoring during and after the infusion.
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Monitor for continued signs of hypovolemia, including urine output < 0.5 mL/kg/hour, poor skin turgor, tachycardia, weak pulse, and hypotension.
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Monitor for signs of hypervolemia such as hypertension, bounding pulse, pulmonary crackles, dyspnea, shortness of breath, peripheral edema, jugular vein distension (JVD) and extra heart sounds such as S3.
I.V. Fluid
Osmolarity
Composition |
Uses/Clinical Considerations |
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0.9% NaCL
(Normal Saline Solution, NSS)
308 mOsm/L Na+ 154 mmol/L Cl- 154 mmol/L
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Fluid of choice for resuscitation efforts.
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Used to replace fluid loss from hemorrhage, severe vomiting or diarrhea, heavy drainage from GI suction, fistulas or wounds.
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Use to treat shock, mild hyponatremia, metabolic acidosis, hypercalcemia.
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Caution in cardiac or renal disease.
- May cause fluid volume overload.
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The only solution that should be administered with blood products.
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Monitor for hyperchloremic acidosis with large volumes of fluid replacement with 0.9%NaCl.
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Lactated Ringer’s Solution
(LR, Ringer’s Lactate)
273 mOsm/L
Na+ 130mEq/L
K+ 4 mEq/L Ca++ 3 mEq/L
Cl- 109 mEq/L
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First-line fluid resuscitation for burn and trauma patients.
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Used to treat acute blood loss or hypovolemia due to third-space fluid shift; GI loss and fistula drainage; electrolyte loss; and metabolic acidosis.
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Contraindicated in patients who cannot metabolize lactate, (i.e. liver disease) or experiencing lactic acidosis.
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Do not administer if pH > 7.5. (Normal liver will convert LR to bicarbonate, worsening alkalosis.)
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Caution in patients with renal failure (LR contains some potassium and hyperkalemia can occur).
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5% dextrose in water
(D5W)
253 mOsm/L
5 g dextrose/100mL
50 g dextrose/L
170 calories/L 3-
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Both isotonic and hypotonic. Initially dilutes osmolality of extracellular fluid (hypotonic); once cell has used dextrose, remaining saline and electrolytes act isotonic, expanding the extracellular compartment.
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Provides free water for the kidneys, aiding renal excretion of solutes. May be used to treat hypernatremia. Should not be used alone to treat fluid volume deficit because it dilutes plasma electrolyte concentrations.
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Contraindicated in resuscitation, early postoperative period, and patients with known or suspected increased intracranial pressure (ICP).
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Provides some calories, but not enough nutrition for prolonged use.
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| Additional isotonic solutions: |
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Ringer’s Solution
Similar to LR but does not contain lactate. Not an alkalizing agent; not ideal for patients with metabolic acidosis.
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PlasmaLyte
Electrolyte composition similar to plasma; can be infused with packed red blood cells. Less likely than other fluids to lead to dilutional or hyperchloremic acidosis.
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