Serum Sodium (Na+)

 Sodium is a major cation of extracellular fluid that maintains osmotic pressure and acid-base balance, and assists in the transmission of nerve impulses. Sodium is absorbed from the small intestine and excreted in the urine in amounts dependent on dietary intake.

Normal Lab Values for Serum Sodium

• 135-145 mEq/L

Indications for Serum Sodium

• Determine whole-body stores of sodium, because the ion is predominantly extracellular
• Monitor the effectiveness of drug, especially diuretics, on serum sodium levels.

Nursing consideration for Serum Sodium

• Drawing blood samples from an extremity in which an intravenous (IV) solution of sodium chloride is infusing increases the level, producing inaccurate results.