Fluid and Electrolytes in Nursing

Importance of Fluid and Electrolyte Balance

• Essential for maintaining life.
• 70% of the body is made up of water.
• Functions:
  • Brain, muscle, bones function.
  • Transport nutrients and oxygen.
  • Blood consists of 83% water.

What are Electrolytes?

• Substances that produce an electrical charge when dissolved in water.
• Six main electrolytes:
  • Potassium
  • Sodium
  • Chloride
  • Calcium
  • Phosphate
  • Magnesium

Functions of Electrolytes

• Muscle contraction.
• Nerve impulses.
• Bone creation.
• Fluid balance (osmosis).
• Acid-base balance.

Maintenance of Electrolytes

• Absorbed from food and drink.
• Major absorption in the gut.
• Filtered by kidneys:
  • Nephrons filter blood.
  • Filtrate becomes urine.
  • Electrolytes are balanced via urine excretion.

Factors Affecting Electrolyte Balance

• Kidney problems lead to imbalance.
• Diuretics and dialysis can influence levels.
• Loss through trauma, burns, vomiting, diarrhea, and suction.
• Diseases like Addison's, SIADH, and hormonal issues.

Electrolyte Imbalances

Sodium (Na)

• Extracellular concentration.
• Regulates water balance, muscle contraction, and nerve impulses.
• Normal: 135-145 mEq/L
  • Hyponatremia (<135 mEq/L):
    • Causes: Low intake, diuretics, GI loss, Addison's disease, SIADH.
    • Symptoms: Seizures, stupor, abdominal cramps, lethargy, decreased reflexes, orthostatic hypotension.
  • Hypernatremia (>145 mEq/L):
    • Causes: Hormonal imbalances, low water intake, diabetes insipidus, excessive sodium intake.
    • Symptoms: Fatigue, restlessness, increased reflexes, extreme thirst, dry mouth.

Chloride (Cl)

• Related to sodium; affects acid-base balance and digestion.
• Normal: 95-105 mEq/L
  • Hypochloremia:
    • Causes: GI loss, diuretics, cystic fibrosis, fluid overload.
    • Symptoms: Dehydration signs, lethargy, low blood pressure.
  • Hyperchloremia:
    • Causes: Excess sodium, dehydration, reduced bicarb, aldosteronism, medications.
    • Symptoms: Similar to hypernatremia, acidosis.

Potassium (K)

• Intracellular; crucial for muscle contraction and nerve impulses.
• Normal: 3.5-5 mEq/L
  • Hypokalemia (<3.5 mEq/L):
    • Causes: Diuretics, corticosteroids, insulin excess, Cushing's syndrome, GI loss.
    • Symptoms: Lethargy, shallow respirations, cardiac dysrhythmias, leg cramps.
  • Hyperkalemia (>5 mEq/L):
    • Causes: Cellular trauma, Addison's, renal failure, medications.
    • Symptoms: Muscle weakness, low urinary output, respiratory failure, rhythm changes.

Calcium (Ca)

• Bone health, nerve conduction, and clotting.
• Normal: 8.5-10.5 mg/dL
  • Hypocalcemia (<8.5 mg/dL):
    • Causes: Low parathyroid hormone, low vitamin D, CKD, certain medications.
    • Symptoms: Convulsions, hyperactive reflexes, muscle spasms, Chvostek's and Trousseau's signs.
  • Hypercalcemia (>10.5 mg/dL):
    • Causes: Hyperparathyroidism, excess vitamin D, cancer, medications.
    • Symptoms: Muscle weakness, EKG changes, absent reflexes, kidney stones.

Magnesium (Mg)

• Intracellular; affects nerve and muscle function.
• Normal: 1.5-2.5 mg/dL
  • Hypomagnesemia (<1.5 mg/dL):
    • Causes: Low intake, malabsorption, alcoholism, medications.
    • Symptoms: Hyperactive reflexes, muscle cramps, torsades de pointes.
  • Hypermagnesemia (>2.5 mg/dL):
    • Causes: Excess supplementation, renal failure.
    • Symptoms: Lethargy, EKG changes, absent reflexes, hypotension.

Phosphate (PO4)

• Bone and teeth building; regulated by parathyroid and vitamin D.
• Normal: 2.5-4.5 mg/dL
  • Hypophosphatemia (<2.5 mg/dL):
    • Causes: Antacid overuse, starvation, hyperparathyroidism, low vitamin D.
    • Symptoms: Bone pain, osteomalacia, neurological changes.
  • Hyperphosphatemia (>4.5 mg/dL):
    • Causes: Laxative overuse, renal failure, hypoparathyroidism.
    • Symptoms: Similar to hypocalcemia, itching, muscle spasms.

Conclusion

• Understanding electrolytes is crucial for nursing.
• Imbalances can affect many body systems.
• Access additional resources and quizzes for deeper understanding.