Fluid and Electrolyte Therapy

Types of therapy

  1. Maintenance therapy
    • Provides water, electrolytes, glucose, vitamins, and in some instances protein to meet daily requirements.
  2. Restoration of deficits
    • In addition to maintenance therapy, fluid and electrolytes are added to replace previous losses.
  3. Replacement therapy
    • Infusions to replace current losses in fluid and electrolytes.

Types of intravenous fluids

  1. 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

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