Electrolytes

Electrolyte Overview

Intracellular Cation: Potassium (3.5 - 5.0 mEq/L)

  • Functions:

    • Regulates muscle activity and cardiac functions.

    • Important for acid-base balance and enzyme reactions.

  • Key Signs of Hyperkalemia:

    • Peaked T waves on ECG.

    • Increased neuromuscular irritability and deep tendon reflexes.

    • Symptoms: Restlessness, intestinal cramping, diarrhea.

    • Severe cases include muscle weakness/loss of tone and paralysis.

  • Key Signs of Hypokalemia:

    • Flat T waves on ECG and arrhythmias.

    • Decreased neuromuscular excitability, skeletal muscle weakness, and smooth muscle wasting.

Extracellular Cation: Sodium (135 - 145 mEq/L)

  • Functions:

    • Controls water, blood volume, blood pressure, and nerve impulses.

  • Signs of Sodium Gain (Hypernatremia):

    • Jugular venous distention (JVD), bounding pulse, increased thirst, weight gain, increased blood pressure.

  • Signs of Water Loss (Hyponatremia):

    • Increased thirst + heart rate, decreased weight + blood pressure.

    • CNS symptoms include hyperactive reflexes, muscle twitching, convulsions.

  • Life-Threatening Signs:

    • Cerebral edema and increased intracranial pressure.

    • Decreased reflexes, seizures, lethargy, confusion, coma.

  • Signs of Pure Sodium Loss:

    • Hypotension, decreased urine output, tachycardia.

  • Signs of Excess Water Dilution:

    • Weight gain, edema, ascites, JVD.

Extracellular Anion: Chloride (97 - 105 mEq/L)

  • Functions:

    • Follows Sodium’s roles in controlling blood volume, acid-base balance, and gas exchange.

  • Signs: Same as Hypernatremia and Hyponatremia.

Cation in the Skeletal System: Calcium (8.8 - 10.5 mEq/L)

  • Functions:

    • Important for bone and teeth formation, regulates heart rate, nerve transmission, and clotting.

  • Signs of Hypercalcemia:

    • Dysrhythmias, bradycardia, cardiac arrest.

  • General Symptoms:

    • Fatigue, weakness, lethargy, anorexia, nausea, constipation.

  • Bone Symptoms:

    • Pain and osteoporosis.

  • Signs of Hypocalcemia:

    • Increased neuromuscular excitability, tingling, and muscle spasms (Chvostek and Trousseau signs).

    • Severe cases can lead to convulsions and tetany.

Intracellular Anion: Phosphate (2.5 - 5.0 mEq/L)

  • Functions:

    • Bone and teeth formation, energy production (ATP), DNA synthesis, and metabolism of nutrients.

    • Regulates acid-base balance, and calcium levels, and supports muscle/nerve functions.

  • Symptoms Similar to Hypocalcemia:

    • Irregularities in leukocyte and platelet functions, and deranged nerve/muscle functions.

  • Severe Symptoms:

    • Irritability, confusion, numbness, coma, convulsions, respiratory failure, and cardiomyopathies.

Intracellular Cation: Magnesium (1.8 - 3.0 mEq/L)

  • Functions:

    • Muscle relaxation, cellular metabolism, cardiac regulation, nerve transmission, and blood sugar control.

  • Signs of Hypermagnesemia:

    • Loss of deep tendon reflexes, hypotension, nausea/vomiting, muscle weakness, respiratory distress.

  • Signs of Hypomagnesemia:

    • Behavioral changes, irritability, hypertension, increased reflexes, tachycardia, convulsions, and nystagmus.