1. Fluid Balance, Electrolytes, and Acid-Base Disorders
Chapter 31

2. Drugs Crystalloids and Colloids Electrolytes Acid- Base Agents
Dextran 40 (Gentran 40, LMD, others)
Electrolytes
Sodium chloride (NaCl)
Potassium chloride (KCL)
Acid- Base Agents
Sodium bicarbonate

3. Frequent indications for IV therapy
Drugs to reverse:
Fluid Balance Deficit/Excess
Electrolyte Imbalance
Acid-base Disorders

4. Body Fluid Compartments
Intracellular
Extracellular
Interstitial
Intravascular
Transcelluar
Diffusion
Active Transport
Osmosis

5. Frequent indications for IV therapy
Fluid Volume Deficit ?
Fluid Volume Excess ?
Two basic types of replacement:
Crystalloids
Colloids

6. Crystalloids Contain electrolytes
Used to replace fluids and promote urine output
Capable of leaving plasma and moving to interstitial spaces and intracellular fluid
Isotonic
Hypertonic
Hypotonic

7. Colloids Molecules too large to easily cross capillary membrane
Stay in intravascular space
Rapidly expand plasma volume
Draw water from intracellular fluid and interstitial spaces into plasma

8. Electrolytes Positively or negatively charged inorganic molecules
Essential to
Nerve conduction, membrane permeability
Water balance, other critical body functions

9. Electrolytes Sodium (135mEq/L-145mEq/L) Potassium (3.5mEq/L-5mEq/L
Essential for maintaining osmolality, water balance, acid-base balance
Potassium (3.5mEq/L-5mEq/L
Essential for
Proper nerve and muscle function
Maintaining acid-base balance
Imbalances can be serious , even fatal

10. Electrolytes Prototype drug: sodium chloride
Mechanism of action: as electrolyte/sodium supplement
Primary use: to treat hyponatremia when serum levels fall below 130mEq/L
Adverse effects: hypernatremia and pulmonary edema

11. Sodium Replacement Therapy
Assess sodium and electrolyte balance
Be alert for signs of hyponatremia or hypernatremia
Client should report symptoms that may relate to fluid overload
Client should drink water or balanced sports drinks to replenish lost fluids and electrolytes

12. Electrolytes Prototype drug: potassium chloride
Mechanism of action: as electrolyte/potassium supplement
Primary use: to treat hypokalemia
Adverse effects: GI irritation, hyperkalemia; contraindicated in clients with chronic renal failure or those taking potassium-sparing diuretic

13. Potassium Replacement Therapy
Monitor for cardiac abnormalities
Do not use with potassium-sparing diuretics
Take with meals to avoid irritating GI tract
Can be given PO/IV
If IV, administer slowly
No IV Push

14. Dextran 40 Colloid= plasma volume expander
Mechanism of action: to maintain plasma osmotic pressure and transport substances through blood
Primary use: restoration of plasma volume and blood proteins
Adverse effects: overload

15. Alkalosis and Acidosis
Normal narrow range
Acidosis is excess acid (pH below 7.35)
Alkalosis is excess base (pH above 7.45)
Both symptoms of underlying disorder
Buffers (lungs/kidneys):
Bicarbonate ions
Phosphate ions

16. Alkalosis and Acidosis
Respiratory
Metabolic (Renal)

18. Pharmacotherapy of Acidosis
Symptoms affect central nervous system
Lethargy, confusion, coma
Deep, rapid respirations in attempt to blow off excess acid
Goal is to quickly reverse effects of excess acid in blood
Administration of bicarbonate is appropriate pharmacotherapy

20. Acid-Base Agents Prototype: sodium bicarbonate
Mechanism of action: to decrease pH of body fluids
Primary use: acidosis or bicarbonate deficiency
metabolic alkalosis caused by receiving too much bicarbonate ion and hypokalemia

21. Pharmacotherapy of Alkalosis
Symptoms are due to central- nervous- system stimulation
Nervousness, hyperactive reflexes, convulsions
Slow, shallow respirations in attempt to retain acid
Treatment
Administration of ammonium chloride (severe cases)
Administration of sodium chloride with potassium chloride (mild cases)