Fluid and Electrolyte Therapy
Types of therapy
- Maintenance therapy
- Provides water, electrolytes, glucose, vitamins, and in some instances protein to meet daily requirements.
- Restoration of deficits
- In addition to maintenance therapy, fluid and electrolytes are added to replace previous losses.
- Replacement therapy
- Infusions to replace current losses in fluid and electrolytes.
Types of intravenous fluids
- Isotonic solutions
a. Fluids that approximate the osmolarity (280-300 mOsm/L) of normal blood plasma.
- Sodium Chloride (0.9%) - Normal Saline
Indications:
- Extracellular fluid replacement when Cl- loss is equal to or greater the Na loss.
- Treatment of matebolic alkalosis.
- Na depletion
- Initiating and terminating blood transfusions.
Possible side effects:
- Hypernatremia
- Acidosis
- Hypokalemia
- Circulatory overload.
b. Five percent dextrose in water (D5W).
- Provides calories for energy, sparring body protein and preventing ketosis resulting from fat breakdown.
Indications:
- Dehydration
- Hypernatremia
- Drug administration
Possible side effects:
- Hypokalemia
- Osmotic diuresis – dehydration
- Transient hyperinsulinism
- Water intoxication.
c. Five percent dextrose in normal saline (D5NS).
- Prevents ketone formation and loss of potassium and intracellular water.
Indications:
- Hypovolemic shock – temporary measure.
- Burns
- Acute adrenocortical insufiency.
Possible side effects:
- Hypernatremia
- Acidosis
- Hypokalemia
- Circulatory overload
d. Isotonic multiple-electrolyte fluids.
- Used for replacement therapy; ionic composition approximates blood plasma.
Types:
- a. Plasmanate
- b. Polysol
- c. Lactated Ringers
Indications:
- Vomiting
- Diarrhea
- Excessive diuresis
- Burns
Possible side effects:
- Circulatory overload.
- Lactated Ringers is contraindicated in severe metabolic acidosis and/or alkalosis and liver disease.
- Hypernatremia
- Acidosis
- Hypokalemia
2. Hypertonic solutions
- Fluids with an osmolarity much higher than 310 mOsm (+ 50 mOsm); increase osmotic pressure of blood plasma, thereby drawing fluid from cells.
a. Ten percent dextrose in normal saline
- Administered in large vein to dilute and prevent venous trauma.
Indications:
- Nutrition
- Replenish Na and Cl.
Possible side effects:
- Hypernatremia (excess Na)
- Acidosis (excess Cl)
- Circulatory overload.
b. Sodium Chloride solutions, 3% and 5%
Indications:
- Slow administration essential to prevent overload (100 mL/hr)
- Water intoxication
- Severe sodium depletion
3. Hypotonic solutions
- Fluids whose osmolarity is significantly less than that of blood plasma (-50 mOsm); these fluids lower plasma osmotic pressure, causing fluid to enter cells.
a. 0.45% sodium chloride
- Used for replacement when requirement for Na use is questionable.
b. 2.5% dextrose in 0.45% saline, also 5% in 0.2 % NaCl
- Common rehydrating solution.
Indications:
- Fluid replacement when some Na replacement is also necessary.
- Encourage diuresis in clients who are dehydrated.
- Evaluate kidney status before instituting electrolyte infusions.
Possible side effects:
- Hypernatremia
- Circulatory overload
- Used with caution in clients who are edematous, appropriate electrolytes should be given to avoid hypokalemia.
Table of Commonly Used IV Solutions
Name of Solution
|
Type of Solution
|
Ingredients in
1-Liter
|
Uses
|
Complications
|
0.45% Sodium Chloride
Shorthand Notation:
½NS
|
Hypotonic
pH 5.6
|
77 mEq Sodium
77 mEq Chloride
|
hypotonic hydration; replace sodium and chloride; hyperosmolar diabetes
|
if too much is mixed with blood cells during transfusions, the cells will pull water into them and rupture
|
0.9% Sodium Chloride
Shorthand Notation:
NS
|
Isotonic
pH 5.7
|
154 mEq Sodium
154 mEq Chloride
|
isotonic hydration; replace sodium and chloride; alkalosis; blood transfusions (will not hemolyze blood cells)
|
None known
|
3% Sodium Chloride
|
Hypertonic
pH 5.0
|
513 mEq Sodium
513 mEq Chloride
|
symptomatic hyponatremia due to excessive sweating,
vomiting, renal impairment, and excessive water intake
|
rapid or continuous infusion can result in hypernatremia or
hyperchloremia
|
5% Sodium Chloride
|
Hypertonic
pH 5.8
|
855 mEq Sodium
855 mEq Chloride
|
||
5% Dextrose in Water
Shorthand Notation:
D5W
|
Isotonic
pH 5.0
|
5 grams dextrose
(170 calories/liter)
|
isotonic hydration; provides some calories
|
water intoxication and dilution of body’s electrolytes with long, continuous infusions
|
10% Dextrose in Water
Shorthand Notation:
D10W
|
Hypertonic
pH 4.3
|
10 grams dextrose
(340 calories/liter)
|
may be infused peripherally;
hypertonic hydration; provides some calories
|
|
5% Dextrose in 1/4 Strength (or 0.25%) Saline
Shorthand Notation:
D5¼NS
|
Hypertonic
pH 4.4
|
5 grams Dextrose
34 mEq Sodium
34 mEq Chloride
|
fluid replacement; replacement of sodium, chloride and some calories
|
vein irritation because of acidic pH, causes agglomeration (clustering) if used with blood transfusions; hyperglycemia with rapid infusion leading to osmotic diuresis
|
5% Dextrose in 0.45 Sodium Chloride
Shorthand Notation:
D5½NS
|
Hypertonic
pH 4.4
|
5 grams Dextrose
77 mEq Sodium
77 mEq Chloride
|
hypertonic fluid replacement; replace sodium, chloride, and some calories
|
|
5% Dextrose in Normal Saline
Shorthand Notation:
D5NS
|
Hypertonic
pH 4.4
|
5 grams Dextrose
154 mEq Sodium
154 mEq Chloride
|
hypertonic fluid replacement; replace sodium, chloride and some calories
|
|
Ringer’s Injection, U.S.P.
|
Isotonic
pH 5.8
|
147 mEq Sodium
4 mEq Potassium
4 mEq Calcium
155 mEq Chloride
|
electrolyte replacement; hydration; often used to replace extracellular fluid losses
|
rapid administration leads to excessive introduction of electrolytes and leads to fluid overload and congestive conditions; provides no calories and is not an adequate maintenance solution if abnormal fluid losses are present
|
Lactated Ringer’s
Shorthand Notation:
LR
|
Isotonic
pH 6.6
|
130 mEq Sodium
4 mEq Potassium
3 mEq Calcium
109 mEq Chloride
28 mEq Sodium Lactate (provides 9 calories/liter)
|
isotonic hydration; replace electrolytes and extra-
cellular fluid losses; mild to moderate acidosis (the lactate is metabolized into bicarbonate which counteracts the acidosis)
|
not enough electrolytes for maintenance; patients with hepatic disease have trouble metabolizing the lactate; do not use if lactic acidosis is present
|
5% Dextrose in Lactated Ringer’s Injection
Shorthand Notation:
D5LR
|
Hypertonic
pH 4.9
|
5 grams Dextrose
(170 calories/liter)
130 mEq Sodium
4 mEq Potassium
3 mEq Calcium
109 mEq Chloride
28 mEq Sodium Lactate (provides 9 calories/liter)
|
hypertonic hydration; provides some calories; replace electrolytes and extra-
cellular fluid losses; mild to moderate acidosis (the lactate is metabolized into bicarbonate which counteracts the acidosis), the dextrose minimizes glycogen depletion
|