Phosphorus
CPT Code(s):
84100
Turnaround Time:
4 hours
Specimen Requirements
Preferred Specimen:
Serum
Minimum Volume:
1.0 mL
Transport Container:
Serum Separator Tube (SST) or Red Top Tube
Transport Temperature:
Room Temperature
Collection Instructions:
Allow blood to clot completely prior to centrifugation. Separate serum from cells within 45 minutes of collection.
Rejection Criteria:
Citrate, Fluoride,Sodium Heparin, or EDTA plasma specimen; gross hemolysis; lipemia; improper labeling
Stability Criteria
Room Temperature:
8 hours
Refrigerated:
7 days
Frozen:
30 days
Clinical Significance
Phosphorus is clinically significant and diagnostically useful in measuring the levels of phosphorus in a patient's blood. Phosphorus is an essential mineral that plays a crucial role in various physiological processes in the body, including bone health, energy production, and cellular function.
The specific clinical significance and diagnostic use of Phosphorus include:
1. Assessment of Bone Health: Phosphorus is a key component of hydroxyapatite, the mineral matrix of bones and teeth. The test helps evaluate the adequacy of phosphorus levels in the body, which is essential for maintaining bone strength and integrity. Abnormal phosphorus levels can indicate conditions such as osteoporosis, rickets, or renal osteodystrophy.
2. Monitoring Kidney Function: The kidneys play a vital role in regulating phosphorus levels in the body. Phosphorus is particularly important for patients with chronic kidney disease (CKD) or other kidney-related conditions. Elevated phosphorus levels, known as hyperphosphatemia, can occur in kidney dysfunction and may contribute to complications such as vascular calcification and mineral bone disorder.
3. Evaluation of Calcium-Phosphorus Balance: Phosphorus and calcium work in tandem to maintain mineral balance in the body. Phosphorus, along with calcium and parathyroid hormone tests, helps assess the balance between these minerals. Imbalances, such as a high phosphorus-to-calcium ratio, can indicate underlying disorders like parathyroid dysfunction or vitamin D deficiency.
4. Monitoring and Adjusting Medications: Certain medications, such as phosphate binders and vitamin D supplements, are commonly prescribed to manage phosphorus levels in patients with kidney disease or other conditions. Phosphorus aids in monitoring the effectiveness of these medications and guiding dose adjustments to maintain optimal phosphorus levels.
5. Evaluation of Nutritional Status: Phosphorus is present in various food sources, and Phosphorus can provide insights into a patient's nutritional status. Low phosphorus levels, known as hypophosphatemia, may be associated with malnutrition, malabsorption disorders, or certain dietary restrictions.
6. Diagnosis and Management of Metabolic Disorders: Abnormal phosphorus levels can be observed in metabolic disorders such as hyperparathyroidism, hypoparathyroidism, and certain inherited conditions like familial hypophosphatemia. Phosphorus aids in diagnosing and monitoring these conditions, guiding treatment strategies, and assessing treatment response.
Overall, Phosphorus is valuable in assessing bone health, monitoring kidney function, evaluating calcium-phosphorus balance, adjusting medications, assessing nutritional status, and diagnosing metabolic disorders. It provides critical information for healthcare providers to manage and optimize patient care, particularly in conditions affecting bone metabolism, kidney function, and mineral balance. Interpretation of the test results should consider the patient's clinical history, concurrent medications, and other relevant laboratory findings to provide comprehensive patient management.