Synonyms
Special Instructions
Expected Turnaround Time
Within 1 day
Specimen Requirements
Specimen
Within 1 day
Volume
1 mL
Minimum Volume
0.7 mL (Note: This volume does not allow for repeat testing.)
Container
Red-top tube, gel-barrier tube, or green-top (lithium heparin) tube. Do not use oxalate, EDTA, or citrate plasma.
Collection
Separate serum or plasma from cells within 45 minutes of collection; avoid hemolysis.
Storage Instructions
Maintain specimen at room temperature or refrigerate.
Causes for Rejection
Hemolysis; improper labeling; unspun or improperly spun specimen
Test Details
Use
Evaluate electrolyte balance; followed patients on diuretic therapy and with renal diseases, particularly salt-losing nephropathy; evaluate patients being treated for acidosis; prevent cardiac arrhythmias; evaluate alcoholism with delirium tremens; evaluate and treat ketoacidosis in diabetes mellitus; evaluate acid-base balance, water balance; manage intravenous therapy; evaluate anion gap; evaluate muscular weakness, leukemia, diseases of the gastrointestinal tract including laxative abuse, large villous adenomas, emesis, fistulas and tube drainage; detect, diagnose, and manage mineral corticoid excess (primary aldosteronism, Cushing syndrome, tumor with ectopic ACTH production, some cases of congenital adrenal hyperplasia); licorice ingestion. Potassium is increased in oliguria, anuria, urinary obstruction, renal failure due to shock (decreased removal of potassium), and renal tubular acidosis. Potassium is decreased in three ways:
• Inadequate intake
• Excessive loss due to diarrhea or vomiting or decreased reabsorption due to increased secretion of mineralocorticosteroids
• Movement into the cell as occurs with conditions causing alkalosis