Electrolytes

Electrolytes Disturbances - AMBER MOORE, MSN, APRN - SPRING 2025

Objectives

  • Describe the etiology, laboratory diagnostic findings, clinical manifestations, and nursing and interprofessional management of the following disorders:

    • Sodium Imbalances: Hypernatremia and Hyponatremia

    • Potassium Imbalances: Hyperkalemia and Hypokalemia

    • Magnesium Imbalances: Hypermagnesemia and Hypomagnesemia

    • Calcium Imbalances: Hypercalcemia and Hypocalcemia

    • Phosphate Imbalances: Hyperphosphatemia and Hypophosphatemia

  • Identify the specific lab values, disease processes affecting these values, methods to correct the problems, and nursing interventions to reduce patient's risk factors.

Definition of Electrolytes

  • Electrolytes are electrically charged particles dissolved in water or gas.

  • This electrical charge causes cellular reactions and regulates body fluid distribution, expressed in MEQ/L (milliequivalents per liter).

Specific Electrolytes

Sodium (Na+)

  • Regulates blood osmolality, fluid volume, and neurological function.

  • Normal range: 136-145 mEq/L

Potassium (K+)

  • Critical for cardiac function and muscle activities.

  • Normal range: 3.5-5.0 mEq/L

    • Memorize these ranges

Calcium (Ca++)

  • Important for bone, muscle, and cardiac functions.

  • Has an inverse relationship with phosphorus.

  • Normal range: 9.0-10.5 mg/dL

Phosphorus (PO4)

  • Also has an inverse relationship with calcium.

  • Normal range: 3.0-4.5 mg/dL

Magnesium (Mg++)

  • Primarily absorbed via the gastrointestinal tract; significant in cardiac function.

  • Normal range: 1.3-2.1 mg/dL

Major Intracellular Electrolytes

  • Potassium (K+)

  • Magnesium (Mg++)

  • Phosphate (HPO4-)

  • Sulfate (SO4-)

  • Other electrolytes are present in small quantities within cells.

Major Extracellular Electrolytes

  • Sodium (Na+)

  • Chloride (Cl-)

  • Bicarbonate (HCO3-)

  • Calcium (Ca++)

Hyponatremia

  • Defined as serum sodium less than 136 mEq/L.

  • Common causes include:

    • Increased water gain diluting sodium (e.g., fluid overload, increased ADH).

    • Rarely due to low sodium intake.

Sodium Loss Causes

  • Diaphoresis, vomiting, diarrhea, feeding tube (NGT) suction.

  • Overuse of diuretics.

  • Adrenal insufficiency.

Manifestations

  • Symptoms include:

    • Nausea, abdominal cramps, weakness, fatigue.

    • Confusion, irritability, personality changes, potentially a coma with severe cases.

Prevention and Correction

  • To prevent:

    • Use normal saline for irrigations instead of distilled water.

    • Teach patients to replace fluid losses with juices instead of plain water.

  • To correct:

    • Administer prescribed hypertonic IV solutions cautiously (e.g., 3% NaCl).

Hypernatremia

  • Defined as serum sodium greater than 145 mEq/L.

  • Caused by excess sodium gain or water loss.

Increased Water Loss Causes

  • Watery diarrhea

  • Diabetes Insipidus

Decreased Water Intake Causes

  • Inadequate water consumption or excessive sodium intake.

Manifestations

  • Behavioral changes, confusion, lethargy, dry mucous membranes, extreme thirst, muscle weakness.

Prevention and Correction

  • To prevent:

    • Administer water between hypertonic tube feedings.

    • Teach elderly to drink fluids regularly.

  • To correct:

    • Monitor water replacement; use diuretics if applicable.

Hypokalemia

  • Defined as serum potassium less than 3.5 mEq/L.

Causes

  • Inadequate intake, excessive renal loss (diuretics), intestinal losses (vomiting), skin losses.

Manifestations

  • Muscle weakness, flaccid muscles, decreased bowel motility, confusion, potentially life-threatening cardiac arrhythmias.

Prevention and Correction

  • To prevent:

    • Educate on high potassium foods (e.g., bananas, spinach).

  • To correct:

    • Administer potassium supplements as ordered, use IV KCl cautiously.

Hyperkalemia

  • Defined as serum potassium greater than 5 mEq/L.

Causes

  • Medications, impaired renal excretion, adrenal insufficiency.

Manifestations

  • Cardiotoxicity, muscle dysfunction, GI hyperactivity, mental confusion.

Prevention and Correction

  • To prevent:

    • Monitor potassium infusions, educate on dietary restrictions.

  • To correct:

    • Administer fluids, administer sodium bicarb, use cation exchange resin if indicated.

Hypocalcemia

  • Defined as serum calcium less than 9.0 mg/dL.

Causes

  • Vitamin D deficiency, chronic insufficient dietary intake, hypoparathyroidism.

Manifestations

  • Muscle cramps, confusion, irritability, potential cardiac issues.

Prevention and Correction

  • To prevent:

    • Educate on dietary sources of calcium and vitamin D.

  • To correct:

    • Administer calcium supplements as ordered.

Hypercalcemia

  • Defined as serum calcium greater than 10.5 mg/dL.

Causes

  • Hyperparathyroidism, metastatic carcinoma, excessive vitamin D.

Manifestations

  • Muscle weakness, confusion, pathological fractures.

Prevention and Correction

  • To prevent:

    • Increase client mobility, restrict vitamin D.

  • To correct:

    • Administer diuretics and isotonic saline as prescribed.

Hypomagnesemia

  • Defined as serum magnesium less than 1.3 mg/dL.

Causes

  • Chronic alcoholism, kidney disease, diuretics.

Manifestations

  • Dysphasia, muscle weakness, seizures, cardiac arrhythmias.

Prevention and Correction

  • To prevent:

    • Provide diet counseling for at-risk patients.

  • To correct:

    • Administer IV magnesium as ordered and monitor renal function.

Hypermagnesemia

  • Defined as serum magnesium greater than 2.1 mg/dL.

Causes

  • Can occur in renal failure, especially with magnesium administration.

Manifestations

  • Hypotension, CNS depression, potential respiratory depression.

Prevention and Correction

  • To prevent:

    • Educate on Mg++ containing antacids.

  • To correct:

    • Administer fluids to increase urinary output, provide emergency calcium gluconate if indicated.

Hypophosphatemia

  • Defined as serum phosphate less than 2.7 mg/dL.

Causes and Manifestations

  • Can indicate a total body deficit or a shift into cells, leading to muscle weakness, confusion, and decreased heart contractility.

Prevention and Correction

  • To prevent:

    • Increase dairy products, consider phosphate oral medication.

  • To correct:

    • Administer IV sodium or potassium phosphate.

Hyperphosphatemia

  • Defined as serum phosphate greater than 4.5 mg/dL.

Causes and Manifestations

  • Commonly related to renal failure, may cause symptoms through secondary hypocalcemia.

Prevention and Correction

  • To prevent:

    • Restrict dairy, ensure hydration.

  • To correct:

    • Administer calcium supplements, dietary phosphate restrictions.