Osmolality, Serum or Plasma
Also known as: OSMO
Use
The osmolality test measures the concentration of solutes in the serum or plasma. It is primarily used to evaluate fluid balance in the body, diagnosis of disorders accompanied by osmolality imbalance like central diabetes insipidus or SIADH, and to monitor treatments affecting fluid status. Serum osmolality is influenced by electrolytes, especially sodium, as well as glucose and urea levels.
Special Instructions
Ensure proper collection and preparation of specimens by separating serum or plasma from cells within 2 hours of collection to avoid inaccurate results. Use ARUP standard transport tubes for specimen submission.
Limitations
Test results may be affected by incorrect specimen collection or handling, delayed separation of serum or plasma, or improper storage conditions. Osomolality measurements might be inaccurate if specimens are contaminated or if exogenous substances that influence solute concentration are present.
New York Approved
Methodology
Automated Analyzer (Clinical Chemistry)
Biomarkers
LOINC Codes
- 2692-2
- 2692-2
Result Turnaround Time
1-3 days
Related Documents
For more information, please review the documents below
Specimen
Serum
Volume
0.5 mL
Minimum Volume
0.5 mL
Container
ARUP standard transport tube
Collection Instructions
Separate serum or plasma from cells within 2 hours of collection.
Storage Instructions
Refrigerated.
Causes for Rejection
Specimens not separated from cells within the appropriate time may be rejected.
Stability Requirements
| Temperature | Period |
|---|---|
| Room Temperature | 24 hours |
| Refrigerated | 1 week |
| Frozen | 6 months |