Phosphorus

Message

Performed in Chemistry

Test Code

PHOS

CPT Codes
84100

Preferred Specimen

Green Top LiHep, Plasma
WyMCC - SST

Other Acceptable Specimens

Gold/SST or Red Top

Reject Criteria (Eg, hemolysis? Lipemia? Thaw/Other?)

Collected in an outdated/expired tube
Hemolyzed, icteric or lipemic
Contaminated

FDA Status
FDA Approved

Setup Schedule

Daily, Sunday through Saturday

Report Available

Less than 4 hours

Clinical Significance

88 % of the phosphorus contained in the body is localized in bone in the form of calcium phosphate as the apatite Ca2+[Ca3(PO4)2]3 2-. The remainder is involved in intermediary carbohydrate metabolism and in physiologically important substances such as phospholipids, nucleic acids and ATP. Phosphorus occurs in blood in the form of inorganic phosphate and in organically bound phosphoric acid. The small amount of extracellular organic phosphorus is found almost exclusively in the form of phospholipids. The ratio of phosphate to calcium in the blood is approximately 6:10. An increase in the level of phosphorus causes a decrease in the calcium level. The mechanism is influenced by interactions between parathormone and vitamin D. Hypoparathyroidism, vitamin D intoxication and renal failure with decreased glomerular phosphate filtration give rise to hyperphosphatemia. Hypophosphatemia occurs in rickets, hyperparathyroidism and Fanconi's syndrome.

The CPT Codes provided in this document are based on AMA guidelines and are for informational purposes only. CPT coding is the sole responsibility of the billing party. Please direct any questions regarding coding to the payor being billed. Any Profile/panel component may be ordered separately. Reflex tests are performed at an additional charge.