Test Code OSMO Osmolality
EHR Test Codes
| Test Code | Test Name | |
| Atlas | OSMO | Osmolality, Serum |
| Cerner | Osmolality |
Specimen Requirements
Preparation of Patient:
None
Container Type:
Green Top 5mL Lithium Heparin Separator Tube
Or
Gold Top 6mL SST Gel & Clot Activator Tube
Specimen Type:
Plasma or Serum
Specimen Volume:
2.5 mL Plasma or Serum minimum .6 mL
Specimen Handling/Transport:
Separate plasma or serum from cells within 2 hours of collection.
Transport ambient room temperature or refrigerated.
Specimen Stability/Storage:
2 days ambient room temperature
2 days refrigerated 2-8°C
Specimen Rejection:
Frozen samples
Performing Laboratory
Munson Medical Center Laboratories
Chemistry Department
Priority, Frequency, & Turnaround
Priority:
Non-Emergent
Frequency:
24 hours 7 days a week
Turnaround:
0 - 1 days
Methodology
Freezing Point Depression
Reporting
Reference Range:
275 - 295 mOsm/kg H2O
Critical Decision:
None
Clinical Significance
Osmolality is used in assessing the concentrating ability of the kidney. In normal individuals on an average intake, the ratio of urine osmolality to serum osmolality is between 1.0 and 3.0. In patients with renal tubular deficiency the ratio will be below that observed in normal individuals. In polyuria of diabetes insipidus, the ratio will be between 0.2 and 0.7. It is also used to evaluate mannitol treatment for head injury patients. Mannitol will help regulate intracranial pressure.
CPT Code(s)
83930