electrolyte /ilek″trōlīt/ [Gk, elektron + lytos, soluble] , an element or compound that, when melted or dissolved in water or another solvent, dissociates into ions and is able to conduct an electric current. Electrolytes differ in their concentrations in blood plasma, interstitial fluid, and cell fluid and affect the movement of substances between those compartments. Proper quantities of principal electrolytes and balance among them are critical to normal metabolism and function. For example, calcium (Ca) is necessary for relaxation of skeletal muscle and contraction of cardiac muscle; potassium (K) is required for contraction of skeletal muscle and relaxation of cardiac muscle. Sodium (Na) is essential in maintaining fluid balance. Certain diseases, conditions, and medications may lead to a deficiency of one or more electrolytes and to an imbalance among them; for example, certain diuretics and a low-sodium diet prescribed in hypertension may cause hypokalemic shock as a result of a loss of potassium. Diarrhea may cause a loss of many electrolytes, leading to hypovolemia and shock, especially in infants. Careful and regular monitoring of electrolytes and IV replacement of fluid and electrolytes are aspects of acute care in many illnesses. −electrolytic, adj.
