Electrolyte

Definition

Electrolytes are charged minerals dissolved in body fluids that maintain fluid balance, acid-base homeostasis, nerve and muscle function, and other essential processes.

Major Electrolytes and Normal Values

• Sodium (Na+): 135 to 145 mEq/L
• Potassium (K+): 3.5 to 5.0 mEq/L
• Calcium (Ca): 9.0 to 10.5 mg/dL
• Magnesium (Mg): 1.5 to 2.5 mEq/L
• Chloride (Cl): 95 to 105 mEq/L
• Phosphorus (P): 3.0 to 4.5 mg/dL

Clinical Impact of Imbalances

Each electrolyte has distinct signs of excess and deficit. Potassium imbalances are most immediately dangerous due to cardiac effects (peaked T waves in hyperkalemia, flat T waves and U waves in hypokalemia).

Nursing Considerations

Monitor lab values, cardiac rhythm, neurologic status, and muscle function, never push IV potassium; always dilute and use an infusion pump. Correct imbalances gradually to avoid complications like central pontine myelinolysis (too-rapid sodium correction).

NCLEX Relevance

Electrolyte questions are among the most frequent on the exam.