Fundamentals of Nursing / Student's Reviewer

Fluid and Electrolyte Therapy

by · December 4, 2009

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:

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:

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