P016 - ELECTROLYTES, SERUM Detail

Sodium (Na⁺), Potassium (K⁺), and Chloride (Cl⁻) are the principal electrolytes of the body and play a vital role in maintaining fluid balance, osmotic pressure, acid–base equilibrium, and normal cellular function. Sodium is the major extracellular cation responsible for regulation of extracellular fluid volume, blood pressure, nerve impulse transmission, and muscle contraction. Potassium is the main intracellular cation and is essential for maintaining membrane potential, neuromuscular activity, and normal cardiac rhythm. Chloride is the major extracellular anion that works closely with sodium to maintain electrical neutrality, fluid distribution, and acid–base balance, and is also an important component of gastric acid. Estimation of these electrolytes in serum is commonly performed using the ion selective electrode (ISE) method and is routinely used to assess hydration status, electrolyte imbalance, renal function, and metabolic or acid–base disorders. Measurement of sodium, potassium, and chloride is particularly important in emergency and critically ill patients, as disturbances in their levels may be associated with renal, cardiac, hepatic, endocrine, or gastrointestinal disorders and can lead to significant neuromuscular and cardiovascular complications.