Clinical Lab Handbook

10 mL (minimum volume: 5 mL) from a random urine collection in a plastic urine container. No preservative. Send specimen refrigerated.

Potentiometric, Ion-Selective Electrode (ISE)

This procedure provides instructions for quantitatively measuring sodium concentration in urine using VITROS NA slides. Sodium is the main cation of extracellular fluid and plays a major role in controlling acid-base equilibrium and the balance of water between blood and body tissue cells. Sodium is absorbed into the bloodstream from the small intestine and excreted in the urine in amounts that vary depending dietary sodium chloride intake. Urine sodium determinations are a sensitive guide to fluctuations in sodium balance. The kidneys excrete the concentrations of sodium needed to maintain serum sodium levels within the narrow limits required for osmotic equilibrium and electrolyte balance. Elevated sodium levels may be found in adrenocortical insufficiency, dehydration, diabetic acidosis, diuretic therapy, fever, head trauma, salicylate intoxication, starvations, hypoaldosteronism, adrenal failure and SIADH. Decreased urine sodium levels may be found in acute renal failure, diarrhea, emphysema, fluid retention, hypernatremic dehydration, diaphoresis, diuresis, hyperventilation, severe vomiting, cirrhosis, congestive heart failure, shock, malabsorption syndrome and pyloric obstruction.

Monday through Sunday

84300 (Urine Sodium)

81050-Urine timed measurement (For 24 hr collection)