Phosphorus

Message

Performing Lab: Central Lab, Hudson, Lakeview, Regions, Sartell, Westfields

Test Code

0123

Alias/See Also

Sunquest: PHOS

CPT Codes
84100

Preferred Specimen

100 uL Lithium Heparin Plasma (light green-top) tube

Minimum Volume

5 uL (does not include dead volume)

Other Acceptable Specimens

Serum (gold-top, red-top, red/gray-top), Lithium Heparin (light green-top) on ICE

Transport Temperature

Refrigerated

Specimen Stability

Room Temperature: < 1 day
Refrigerated: < 4 days
Frozen: < 1 year at -20 C

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

Hemolysis

Methodology
Rhosphomolybdate

Setup Schedule

Daily

Report Available

Same day

Limitations

Hemolysis produces elevated phosphorus levels due to the inorganic phosphates and phosphatases present in red blood cells.

Reference Range

Age	Reference Range	Critical
>= 16 Years	2.3 - 4.7 mg/dL	<= 1.0 mg/dL >= 10.0 mg/dL
10 - 15 Years	3.3 - 5.4 mg/dL
3 - 9 Years	3.2 - 5.8 mg/dL
0 - 2 Years	4.0 - 6.5 mg/dL

Clinical Significance

Phosphorus, as phosphate, is distributed throughout the body. Causes of high serum phosphorus include dehydration, hypoparathyroidism, hypervitaminosis D, metastases to bone, sarcoidosis, pulmonary embolism, renal failure, and diabetes mellitus with ketosis. Low serum phosphorus is found in primary hyperparathyroidism and other causes of serum calcium elevation, sepsis, vitamin D deficiency, renal tubular disorders, chronic hemodialysis, vomiting, and occasionally with decreased dietary phosphate intake.

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.