Electrolytes and Electrolyte Imbalances

Introduction

• Focus on sodium, calcium, potassium, and magnesium.
• A knowledge check will be provided at the end.
• Use medical surgical nursing flashcards for additional reference.

Sodium (Na)

• Function: Maintains fluid balance and is crucial for nerve and muscle function.
• Normal Range: 136 - 145 mEq/L.

Hypernatremia

• Definition: Sodium level > 145 mEq/L.
• Causes: Excess sodium intake, Cushing's syndrome, diabetes insipidus.
• Symptoms: Thirst, agitation, muscle weakness, GI upset.
• Treatment:
  • Provide hypotonic IV fluids (e.g., 0.45% NaCl).
  • Use diuretics like furosemide.
  • Restrict sodium intake, increase water intake.

Hyponatremia

• Definition: Sodium level < 136 mEq/L.
• Causes: Diuretics, kidney failure, SIADH, heart failure.
• Symptoms: Confusion (especially in the elderly), fatigue, nausea, headache.
• Treatment:
  • Provide hypertonic IV fluid replacement (e.g., 2-3% NaCl).
  • Increase sodium intake, restrict fluid intake.

Calcium (Ca)

• Function: Important for bone and teeth formation, nerve and muscle function, clotting.
• Normal Range: 9 - 10.5 mg/dL; mnemonic: "Call 911" or earthquake range 9-10.5.

Hypercalcemia

• Definition: Calcium level > 10.5 mg/dL.
• Causes: Hyperparathyroidism, corticosteroids, bone cancer.
• Symptoms: Constipation, decreased deep tendon reflexes, kidney stones, lethargy, weakness.
• Treatment:
  • Provide 0.9% NaCl IV fluids.
  • Administer calcitonin.
  • Dialysis for severe cases.

Hypocalcemia

• Definition: Calcium level < 9 mg/dL.
• Causes: Diarrhea, vitamin D deficiency, hypoparathyroidism.
• Symptoms: Positive Chvostek's sign (cheek twitch), positive Trousseau's sign (hand spasm), muscle spasms, numbness in lips/fingers.
• Treatment:
  • Provide calcium supplements.
  • Increase intake of calcium-rich foods.

Potassium (K)

• Function: Maintains intracellular fluid and crucial for nerve and muscle function.
• Normal Range: 3.2 - 5 mEq/L; mnemonic: "Run a 5K is 3.2 miles" or buy bananas in bunches of 3-5.

Hyperkalemia

• Definition: Potassium level > 5 mEq/L.
• Causes: DKA, metabolic acidosis, salt substitutes, kidney failure.
• Symptoms: Dysrhythmias, muscle weakness, numbness, nausea.
• Treatment:
  • Administer furosemide, Kayexalate, insulin (with dextrose to prevent hypoglycemia).
  • Decrease potassium-rich food intake.

Hypokalemia

• Definition: Potassium level < 3.5 mEq/L.
• Causes: Diuretics, GI losses, Cushing's syndrome.
• Symptoms: Dysrhythmias, muscle spasms, constipation.
• Treatment:
  • Provide potassium supplements.
  • Increase intake of potassium-rich foods.

Magnesium (Mg)

• Function: Important for biochemical reactions, muscle and nerve function.
• Normal Range: 1.3 - 2.1 mg/dL; mnemonic: "MG cars fit 1-2 people."

Hypermagnesemia

• Definition: Magnesium level > 2.1 mg/dL.
• Causes: Kidney disease, excess antacids/laxatives.
• Symptoms: Hypotension, lethargy, muscle weakness.
• Treatment:
  • Administer furosemide.
  • Provide calcium to reverse cardiac effects.

Hypomagnesemia

• Definition: Magnesium level < 1.3 mg/dL.
• Causes: GI losses, diuretics, alcohol abuse.
• Symptoms: Dysrhythmias, tachycardia, increased deep tendon reflexes, tremors.
• Treatment:
  • Provide magnesium supplements.
  • Increase intake of magnesium-rich foods.

Knowledge Check

1. Question: Positive Chvostek's and Trousseau's sign indicate what imbalance?
   • Answer: Hypocalcemia.
2. Question: What key side effect occurs with both hyperkalemia and hypokalemia?
   • Answer: Dysrhythmia.
3. Question: Signs of hypomagnesemia include hypotension and decreased deep tendon reflexes: True/False?
   • Answer: False. (Increased DTRs and hypertension).